Human leukocyte antigen alleles, genotypes and haplotypes frequencies in renal transplant donors and recipients from West Central India.

BACKGROUND: Human leukocyte antigen (HLA) is comprised of a highly polymorphic set of genes which determines the histocompatibility of organ transplantation. The present study was undertaken to identify HLA class I and class II allele, genotype and haplotype frequencies in renal transplant recipients and donors from West Central India. MATERIALS AND METHODS: HLA typing was carried out using Polymerase Chain Reaction-Sequence Specific Primer in 552 live related and unrelated renal transplant recipients and donors. RESULTS: The most frequent HLA class I and class II alleles and their frequencies in recipients were HLA-AFNx0101 (0.1685) and AFNx0102 (0.1649), HLA-BFNx0135 (0.1322), and HLA-DR beta 1 (DRB 1)FNx0115 (0.2192), whereas in donors, these were HLA-AFNx0102 (0.1848) and AFNx0101 (0.1667), HLA-BFNx0135 (0.1359), and HLA-DRB1FNx0115 (0.2409). The two-locus haplotype statistical analysis revealed HLA-AFNx0102-B61 as the most common haplotype with the frequency of 0.0487 and 0.0510 in recipients and donors, respectively. Further, among the three locus haplotypes HLA-AFNx0133-BFNx0144-DRB1FNx0107 and HLA-AFNx0102-BFNx0161-DRB1FNx0115 were the most common haplotypes with frequencies 0.0362 and 0.0326, respectively in recipients and 0.0236 and 0.0323, respectively in donors. Genotype frequency revealed a high prevalence of genotype HLA-AFNx0102/AFNx0124 in recipients (0.058) compared to donors (0.0109) whereas low prevalence of HLA-AFNx0101/AFNx0102 in recipients (0.0435) than in donors (0.0797). The phylogenetic and principal component analysis of HLA allele and haplotype frequency distribution revealed genetic similarities of various ethnic groups. Further, case control analysis provides preliminary evidence of association of HLA-A genotype (P < 0.05) with renal failure. CONCLUSION: This study will be helpful in suitable donor search besides providing valuable information for population genetics and HLA disease association analysis.

Feohifomicosis subcutánea en un paciente trasplantado renal / Subcutaneous pheohyphomycosis in a renal transplanted patient

La feohifomicosis es una entidad poco frecuente causada por hongos formadores de hifas de la familia Dematiaceae, afecta principalmente a pacientes inmunosuprimidos, produce lesiones subcutáneas en forma de quistes y pseudoquistes que en su mayoría se tratan con la exéresis quirúrgica y tratamiento medicamentoso con anfotericin B e itraconazol. Se describió un caso de feohifomicosis, en un paciente masculino de 38 años de edad, con antecedentes de enfermedad renal crónica, hepatitis por virus C adquirida en hemodiálisis. Recibe trasplante renal en el 2010 y se le aplica triple terapia inmunosupresora, tacrolimus, micofenolato mofetil y prednisona. Desarrolla diabetes mellitus postrasplante. Un año después del injerto, comienza a presentar lesiones dermatológicas pseudoquísticas violáceas, solitarias, que forman conglomerados, en la pantorrilla, el tobillo y los dedos de ambos pies. Mediante examen clínico, micológico y por biopsia de la lesión se diagnostica feohifomicosis. Se realizó tratamiento quirúrgico con exéresis de las lesiones y medicamentoso con itraconazol 200 mg al día, se modificó el tratamiento inmunosupresor según interacción del itraconazol con los anticalcineurínicos, se sustituyó este por everolimus. Tres meses después se observó evolución satisfactoria

Pheohyphomycosis is a rare disease caused by Dematiaceae family hypha-forming fungi; it mainly affects immunosuppresed patients and causes subcutaneous lesions in the form of cysts and pseudocysts that are mostly treated with surgery and amphotericin B and Itraconazol-based treatment. A case of pheohyphomycosis was presented in a 38 years-old man with a history of chronic renal disease and of hepatitis C caught in hemodialysis. He was a renal transplant recipient in 2010 and was administered a triple immunosuppressive treatment with tacrolimus, mycophenolate mophetil and prednisone. He developed post-transplant diabetes mellitus and one year after the transplantation, he presented with purplish blue-colored pseudocystic dermatological lesions forming clusters in his calves, ankles and toes. The clinical, mycological and biopsy exams of the lesions yielded the diagnosis of pheohyphomycosis. The lesions were surgically removed and then 200mg of itraconazol was administered daily. This treatment was changed on account of the interaction between itraconazol and the anti-calcineuric drugs. The patient was then prescribed everolimus. Three months later, the patient recovered satisfactorily

Epidemiología de la patología tumoral en el trasplante renal / Epidemiology of tumoral pathology in renal transplantation

Introducción: La patología tumoral (PT) implica una morbimortalidad no despreciable después del trasplante renal, siendo la inmunosupresión un factor de riesgo potencialmente responsable de su desarrollo. El objetivo de nuestro estudio es determinar la prevalencia de malignidad durante el trasplante y estudiar su posible asociación con el uso de anticuerpos antilinfocitarios, infección por citomegalovirus y el antecedente de rechazo agudo. Métodos: Se trata de un estudio de cohorte, retrospectivo, en 1034 receptores de trasplante renal en el que se revisaron los eventos tumorales acontecidos entre abril de 1981 y marzo de 2010. Se consignaron el uso de anticuerpos antilinfocitarios (AAL), infección por CMV y episodios de rechazo agudo (RA), relacionando estas variables con el desarrollo posterior de patología tumoral. Resultados: NO se detectó mayor frecuencia de PT maligna en aquellos que recibieron AAL (13,8% vs. 17,6%, p=0,094) p=0,094). No hubo mayor frecuencia de PT en pacientes con infección por CMV (16,3% vs. 15,2%, p=0,69). Por último, hubo mayor frecuencia de PT en aquellos con antecedentes de RA, si bien con significación limítrofe (19,5% vs. 14,3%, p=0,05). Conclusiones: La patología tumoral maligna se ve potencialmente favorecida por la inmunosupresión cada vez más potente y duradera. No hemos encontrado asociación entre la administración de AAL, infección y / o enfermedad por CMV; si bien esta se ve ligeramente incrementada en aquellos pacientes con el antecedente de RA.

Introduction: Tumoral pathology (TP) implies morbidity which is significant after the renal transplantation; Immunosuppression is a risk factor which is potentially responsible for tumoral development. The aim of our study is to determine the prevalence of malignancy during transplantation and to study its possible relation with the usage of antillymphocvte antibodies, cytomegalovirus infection and the history of acute rejection. Methods: It is a cohort study, retrospective, in 1014 receptors of Kidney transplantation in which tumoral events were revised between April 1981 and March 2010. The development of tumoral pathology in recipients was related with the usage of AAL, CMV infection and AR episodes. Results: a greater frequency of malign TP was no recorded in those who received AAL (13.8% vs. 17.6%, p=0.094). There was not greater frequency of TP in patients with infection due to CMV (16,3% vs, 15.2%, p=0.69). Finally, there was greater frequency of TP in those with antecedent of AR, though with bordering significance (19.5%, vs. 14.3% p=0.05). Conclusions: Malign tumoral pathology is potentially favored by immunosuppression increasingly powerful lasting. We have not found any relationship between AAL use, infection and/ or disease due to CMV, although this is slightly increased in those patients with AR history.

Inmunosupresión en donantes renales: Expresión de citoquinas proinflamatorias / Immunosuppression in kidney donors with rapamycin and tacrolimus: Proinflammatory cytokine expression

La lesión por isquemia y reperfusión (IRI) es uno de los principales problemas en el trasplante. Nuestro objetivo fue evaluar el efecto del pre - acondicionamiento al donante con rapamicina y tacrolimus para prevenir la lesión por IRI. Las ratas Wistar donantes, 12 horas antes de la nefrectomía, recibieron fármacos inmunosupresores. La muestra se dividió en cuatro grupos experimentales: un grupo con intervención simulada (sham), un grupo control sin tratamiento, otro tratado con rapamicina (2 mg/kg) y el restante tratado con tacrolimus (0.3 mg/kg). Se retiró el riñón izquierdo y después de tres horas de isquemia fría, se lo trasplantó. Veinticuatro horas después, el órgano trasplantado se recuperó para el análisis histológico y la evaluación de la expresión de citoquinas. El tratamiento de pre-acondicionamiento con rapamicina o con tacrolimus redujo significativamente el nitrógeno ureico en sangre y los niveles de creatinina en comparación con el control (BUN: p < 0.001; creatinina: p < 0.001). La necrosis tubular aguda fue significativamente menor en las ratas donantes tratadas con inmunosupresores en comparación con el grupo control (p < 0.001). Finalmente, las citoquinas inflamatorias, como TNF-α, IL-6 y rIL-21, mostraron niveles más bajos en el injerto de los animales que recibieron tratamiento. Este estudio experimental exploratorio muestra que el pre-acondicionamiento en donantes con rapamicina y tacrolimus en dos grupos distintos mejora los resultados clínicos y anatomopatológicos en receptores, con una reducción in situ de citoquinas pro-inflamatorias relacionadas con la diferenciación Th17, y de este modo crea un ambiente favorable para la diferenciación de células T regulatorias (Tregs).

The ischemia-reperfusion injury (IRI) remains a major problem in transplantation. The objective of this study was to evaluate the effects of preconditioning a donor group with rapamycin and another donor group with tacrolimus to prevent IRI. Twelve hours before nephrectomy, donor Wistar rats received immunosuppressive drugs. The sample was divided into four experimental groups: a sham group, an untreated control group, a group treated with rapamycin (2 mg/kg) and a group treated with tacrolimus (0.3 mg/kg). Left kidneys were removed and, after three hours of cold ischemia, grafts were transplanted. Twenty-four hours later, the transplanted organs were recovered for histological analysis and evaluation of cytokine expression. The pre-conditioning treatment with rapamycin or tacrolimus significantly reduced donor blood urea nitrogen and creatinine levels compared with control group (BUN: p < 0.001 vs. control and creatinine: p < 0.001 vs. control). Acute tubular necrosis was significantly lower in donors treated with immunosuppressant drugs compared with the control group (p < 0.001). Finally, inflammatory cytokines such as TNF-α, IL-6 and rIL-21 showed lower levels in the graft of pre-treated animals. This exploratory experimental study shows that preconditioning donors with rapamycin and tacrolimus in different groups improves clinical outcome and pathology in recipients and reduces in situ pro-inflammatory cytokines associated with Th17 differentiation, creating a favorable environment for the differentiation of regulatory T cells (Tregs).

The impact of pretransplant donor-specific antibodies on graft outcome in renal transplantation: a six-year follow-up study

OBJECTIVE: The significance of pretransplant, donor-specific antibodies on long-term patient outcomes is a subject of debate. This study evaluated the impact and the presence or absence of donor-specific antibodies after kidney transplantation on short- and long-term graft outcomes. METHODS: We analyzed the frequency and dynamics of pretransplant donor-specific antibodies following renal transplantation from a randomized trial that was conducted from 2002 to 2004 and correlated these findings with patient outcomes through 2009. Transplants were performed against a complement-dependent T- and B-negative crossmatch. Pre- and posttransplant sera were available from 94 of the 118 patients (80%). Antibodies were detected using a solid-phase (LuminexH), single-bead assay, and all tests were performed simultaneously. RESULTS: Sixteen patients exhibited pretransplant donor-specific antibodies, but only 3 of these patients (19%) developed antibody-mediated rejection and 2 of them experienced early graft losses. Excluding these 2 losses, 6 of 14 patients exhibited donor-specific antibodies at the final follow-up exam, whereas 8 of these patients (57%) exhibited complete clearance of the donor-specific antibodies. Five other patients developed ''de novo'' posttransplant donor-specific antibodies. Death-censored graft survival was similar in patients with pretransplant donor-specific and non-donor-specific antibodies after a mean follow-up period of 70 months. CONCLUSION: Pretransplant donor-specific antibodies with a negative complement-dependent cytotoxicity crossmatch are associated with a risk for the development of antibody-mediated rejection, although survival rates are similar when patients transpose the first months after receiving the graft. Our data also suggest that early posttransplant donor-specific antibody monitoring should increase knowledge of antibody dynamics and their impact on long-term graft outcome.

Role of Plasma Exchange in ABO-incompatible Kidney Transplantation

BACKGROUND: In the past, ABO incompatibility was an absolute contraindication for solid organ transplantation. However, multiple recent trials have suggested strategies for overcoming the reactions between graft antigens and recipient antibodies that cause graft rejection. In this study, we determined the usefulness of plasma exchange (PE) for removing anti-A/B antibodies that cause hyperacute/acute humoral graft rejection in patients undergoing ABO-incompatible kidney transplantation. METHODS: In our study, 12 patients underwent ABO-incompatible kidney transplantation. All recipients received pre-transplantation conditioning by PE or intravenous immunoglobulin (IVIG) administration. After pre-transplantation conditioning, anti-A/B antibody titers were evaluated, and transplantation was performed when the titer was below 1:8. To assess the transplantation outcome, anti-A/B antibody titers, creatinine level, estimated glomerular filtration rate (eGFR), and proteinuria levels were measured. RESULTS: Anti-A/B antibody titers were below 1:8 in all patients at the time of transplantation. eGFR measured on post-transplant day 14 showed that 10 patients had immediate recovery of graft function, while 2 patients had slow recovery of graft function. Short-term outcomes of ABO-incompatible kidney transplantation (measured as creatinine levels) after reducing anti-A/B antibody titers were similar to those of ABO-compatible kidney transplantation. After transplantation, the anti-A/B antibody titers were below 1:8 in 7 patients, but the remaining 5 patients required post-transplantation PE and IVIG treatment to prevent antigen-antibody reactions. CONCLUSIONS: With the increasing demand for kidney donations, interest in overcoming the ABO incompatibility barrier has increased. PE may be an important breakthrough in increasing the availability of kidneys for transplantation.

Clinical Relevance of Pretransplant HLA Class II Donor-specific Antibodies in Renal Transplantation Patients with Negative T-cell Cytotoxicity Crossmatches

BACKGROUND: We evaluated the clinical relevance of pretransplant donor-specific HLA antibodies (DSA) in renal transplantation patients who had negative T-cell cytotoxicity crossmatches. METHODS: From 328 consecutive renal transplant recipients, we selected 28 patients who had positive pretransplant (historical or at the time of transplantation) flow cytometry crossmatches, but negative T-cell cytotoxicity crossmatches at the time of transplantation. The presence of DSA and its level at the time of transplantation were retrospectively tested using Luminex single antigen assays. RESULTS: DSA was present in 16 (57.1%) of 28 patients. Biopsy-proven acute rejection (9 patients) occurred more frequently in patients with DSA than in those without DSA (56.3% vs. 0.0%; P=0.003). The positivity rate of class II DSA was significantly higher in patients with antibody-mediated rejection (AMR) than in those without AMR (100% vs. 21.7%; P=0.003). However, the positivity rate of class I DSA was not different between the two groups (40% vs. 40.9%). Among patients with class II DSA, those with AMR tended to have higher antibody levels (median fluorescence intensity, MFI) than those without AMR (16,359 vs. 5,910; P=0.056). A cut-off MFI value of 4,487 for class II DSA predicted the occurrence of AMR with good sensitivity and specificity (100% and 87.0%). CONCLUSIONS: In patients with negative T-cell cytotoxicity crossmatches, the presence of class II DSA and its level at the time of transplantation were associated with the occurrence of AMR. Pretransplant DSA measurement with Luminex single antigen assay would be useful in renal transplantation.

Complement-dependent lymphocytotoxicity crossmatch in deceased donor renal transplant: A single institutional experience.

Complement-dependent lymphocytotoxicity crossmatches (n=217) between 47 deceased donors and 150 potential renal recipients were retrospectively studied. A negative cross match was reported in 48 (22.1%), doubtful positive in 126 (58.1%), weakly positive in 32 (14.7%) and positive in 11 (5.1%). No autoantibodies were detected. Renal transplantation was performed in 35.5% of the potential recipients. There was no incidence of hyperacute rejection. The graft survival rate was 88% at 15 months of follow up. The study concludes that a negative pretransplant lympocytotoxicity crossmatch using the basic National Institute of Health technique eliminates hyperacute rejection, but carries drawbacks, which require modification and supplementation with more sensitive and specific assays.

Restriction enzyme analysis of the human cytomegalovirus genome in specimens collected from immunodeficient patients in Belém, State of Pará, Brazil / Análise de restrição enzimática do genoma viral do citomegalovírus humano em espécimes clínicos de pacientes imunodeficientes, Belém, Estado do Pará

INTRODUCTION: Human cytomegalovirus is an opportunistic betaherpesvirus that causes persistent and serious infections in immunodeficient patients. Recurrent infections occur due to the presence of the virus in a latent state in some cell types. It is possible to examine the virus using molecular methods to aid in the immunological diagnosis and to generate a molecular viral profile in immunodeficient patients. The objective of this study was to characterize cytomegalovirus genotypes and to generate the epidemiological and molecular viral profile in immunodeficient patients. METHODS: A total of 105 samples were collected from immunodeficient patients from the City of Belém, including newborns, hemodialysis patients, transplant recipients and HIV+ patients. An IgG and IgM antibody study was completed using ELISA, and enzymatic analysis by restriction fragment length polymorphism (RFLP) was performed to characterize viral genotypes. RESULTS: It was observed that 100 percent of the patients had IgG antibodies, 87 percent of which were IgG+/IgM-, consistent with a prior infection profile, 13 percent were IgG+/IgM+, suggestive of recent infection. The newborn group had the highest frequency (27 percent) of the IgG+/IgM+ profile. By RFLP analysis, only one genotype was observed, gB2, which corresponded to the standard AD169 strain. CONCLUSIONS: The presence of IgM antibodies in new borns indicates that HCMV continues to be an important cause of congenital infection. The low observed genotypic diversity could be attributed to the small sample size because newborns were excluded from the RFLP analysis. This study will be continued including samples from newborns to extend the knowledge of the general and molecular epidemiology of HCMV in immunodeficient patients.

INTRODUÇÃO: O citomegalovírus é um betaherpesvírus oportunista, causador de infecções persistentes e graves em pacientes imunodeficientes. As infecções recorrentes ocorrem devido à presença do vírus em estado de latência, em alguns tipos celulares, o que possibilita a pesquisa viral por métodos moleculares para auxiliar nos diagnósticos imunológicos, assim como traçar o perfil epidemiológico e molecular viral em pacientes imunodeficientes. O objetivo deste estudo foi caracterizar os genótipos de citomegalovírus e traçar o perfil epidemiológico e molecular viral em pacientes imunodeficientes. MÉTODOS: Um total de 105 amostras foi coletado de pacientes imunodeficientes da Cidade de Belém, incluindo recém-nascidos, hemodialisados, transplantados e pacientes HIV+. Foi realizada a pesquisa de anticorpos IgG e IgM pelo método ELISA e análise enzimática pelo método restriction fragment length polymorphism (RFLP) para caracterização dos genótipos virais. RESULTADOS: Foi observado que 100 por cento dos pacientes apresentavam anticorpos IgG, 87 por cento eram IgG+/IgM-perfil de infecção pregressa; e 13 por cento IgG+/ IgM+ sugestivo de infecção recente. O grupo dos recém-nascidos apresentou maior frequência (27 por cento) do perfil IgG+/IgM+. Na análise por RFLP, foi observado um único genótipo, o gB2, que corresponde ao padrão genotípico da cepa AD169. CONCLUSÕES: A presença de anticorpos IgM nos recém-nascidos indica que o vírus CMV continua sendo causa importante de infecção congênita; a baixa diversidade genotípica pode ser atribuída ao tamanho amostral devido a exclusão dos recém-nascidos na análise por RFLP. Esse estudo será continuado incluindo amostras de recém-nascidos a fim de contribuir para um amplo conhecimento da epidemiologia geral e molecular do citomegalovírus em pacientes imunodeficientes da Cidade de Belém.

Manifestações clínicas e evolução da infecção pelo vírus da influenza A (H1N1) em receptores de transplante renal / Clinical manifestations and evolution of infection by influenza A (H1N1) in kidney transplant recipients

INTRODUÇÃO: A emergência do surto pandêmico de influenza A, subtipo H1N1, em abril de 2009, representou um grande desafio para a logística de saúde pública. Embora a maioria dos pacientes infectados apresente manifestações clínicas e evolutivas muito semelhantes às observadas na influenza sazonal, um número significativo de indivíduos evolui com pneumonia e insuficiência respiratória aguda severa. O impacto da infecção pelo vírus influenza A, subtipo H1N1, em pacientes imunossuprimidos não é determinado. MÉTODOS: Neste estudo, foram analisadas a apresentação clínica e a evolução da influenza A, subtipo H1N1, em 19 receptores de transplante renal. Os pacientes receberam confirmação diagnóstica pela técnica de RT-PCR. O manejo clínico incluiu terapêutica antiviral com fosfato de oseltamivir e antibióticos. RESULTADOS: A população estudada foi predominantemente de indivíduos do sexo masculino (79 por cento), brancos (63 por cento), com idade média de 38,6 ± 17 anos e portadores de pelo menos uma comorbidade (53 por cento). A infecção por influenza A, subtipo H1N1, foi diagnosticada em média 41,6 ± 49,6 meses após o transplante. Os sintomas mais comuns foram: tosse (100 por cento), febre (84 por cento), dispneia (79 por cento) e mialgia (42 por cento). Disfunção aguda do enxerto foi observada em 42 por cento dos pacientes. Cinco pacientes (26 por cento) foram admitidos em Unidade de Terapia Intensiva, dois (10 por cento) necessitaram de suporte com ventilação invasiva e dois (10 por cento) receberam drogas vasoativas. A mortalidade foi de 10 por cento. CONCLUSÕES: A disfunção aguda do enxerto renal foi um achado frequente, e as características clínicas, laboratoriais e evolutivas foram comparáveis às da população geral.

INTRODUCTION: The emergence of the pan>demic outbreak of influenza A (H1N1) in April, 2009, represented a logistic challenge for public health. Although most infected patients presented clinical and evolutionary manifestations which were very similar to seasonal influenza, a significant number of individuals developed pneumonia and severe acute respiratory failure. The impact of influenza A (H1N1) in immunocompromised patients is not well established yet. METHODS: This study aimed to analyze the clinical presentations and evolution of influenza A (H1N1) in 19 kidney transplant recipients. Influenza A (H1N1) infection was confirmed by RT-PCR in all patients. Treatment included antiviral therapy with oseltamivir phosphate and antibiotics. RESULTS: The studied population was compounded mostly of white people (63 percent), males (79 percent), at a mean age of 38.6 ± 17 years and patients with at least one comorbidity (53 percent). Influenza A (H1N1) infection was identified 41.6 ± 49.6 months after transplantation. Common symptoms included cough (100 percent), fever (84 percent), dyspnea (79 percent), and myalgia (42 percent). Acute allograft dysfunction was observed in 42 percent of the patients. Five patients (26 percent) were admitted to the Intensive Care Unit, two (10 percent) required invasive ventilation support, and two (10 percent) required vasoactive drugs. Mortality rate was 10 percent. CONCLUSIONS: Acute renal allograft dysfunction was a common finding. Clinical, laboratory, and evolutionary characteristics were comparable to those in the general population.

Caracterización inmunohistoquímica de la función renal en un riñón transplantado en paciente portador de síndrome urémico hemolítico atípico por déficit de factor H: [revisión] / Immunohistochemical characterization of the renal function in transplanted kidney in a carrier of an atypical uremic haemolitic syndrome due to factor H deficit: [review]

El síndrome urémico hemolítico se caracteriza por presentar anemia hemolítica microangiopática, trombocitopenia e insuficiencia renal aguda. Se clasifica en típico, diarrea positivo, inducido por Escherichia coli 0157-H7 (90%) y atípico, más comúnmente secundario a la desregulación de la vía alternativa del complemento (3-10%). La región cromosómica 1q32 contiene el sistema regulador de la activación del complemento humano (RCA). Se relaciona con mutaciones en factores reguladores de C3 como el factor H (FH, la más común), el factor I, el factor B y la proteína constitutiva de membrana (MCP). Presenta patrones de herencia autosómica tanto dominante como recesiva. El déficit de FH autosómico dominante generalmente ocurre en adultos y la mortalidad y el riesgo de enfermedad renal terminal oscila entre el 50%-90%. El objetivo de nuestro trabajo fue estudiar la función tubular y glomerular por técnicas de inmunohistoquímica para detectar mecanismos de transporte para agua (AQPs), urea (UT-A) y proteínas (nefrina, podocalixina y megalina) en un riñón transplantado de un paciente portador de SUH por déficit de FH que desarrolló una recidiva de SUH y lesiones por nefrotoxicidad. Detectamos un mecanismo de adaptación a la uremia por la expresión de novo de un UT-A2 en corteza renal y la disminución del UT-A1 en médula y alteraciones en el manejo proximal del agua por la disminución de la expresión de AQP1 en túbulo proximal. Las modificaciones a nivel de la expresión de la nefrina y la podocalixina podocitarias y de megalina en el túbulo proximal podrían explicar la presencia de proteinuria.

Linfoma no Hodgkin secundario a inmunosupresión por transplate renal tratado con quimioterapia / No Hodgkin lymphoma secondary to immune suppression to renal transplantation treated with chemotherapy

Los síndromes linfoproliferativos posterior a trasplante renal incluyen un grupo de enfermedades linfoides que por definición se presentan después del mismo en un órgano sólido o en la médula ósea y están en relación con la terapia inmunosupresora administrada. La probabilidad de desarrollar una neoplasia maligna en un receptor de trasplante renal seguido a lo largo de 17 años, es de un 14 por ciento para cánceres no cutáneos, de un 47 por ciento en los carcinomas de piel y un 55 por ciento para cualquier tipo de cáncer. En este trabajo se describe un caso poco común de un paciente de 40 años con insuficiencia renal crónica secundario a hipertensión arterial en hemodiálisis, quien se le realizó trasplante renal de cadáver en el 2007, presentando alteración de función renal con masa palpable en fosa ilíaca derecha, en tratamiento con inmunosupresores. El examen histopatológico de la biopsia reportó: desorden linfoproliferativo posterior a trasplante con inmunohistoquímica positivo para CD20, CD79 en células linfoides B y CD45 en células linfoides T. Estudios de extensión metástasis en mediastino concluyéndose como: linfoma no Hodgkin inmunofenotipo B CD20+ estadio IV extra nodal renal con metástasis en mediastino superior mayo/2009 IPI score alto riesgo secundario a trasplante renal. Recibió tratamiento con R-CHOP obteniéndose respuesta oncológica completa, demostrado por CT-PET, actualmente libre de enfermedad, en controles nefrológicos. Se debe vigilar cualquier alteración clínica, ya que un rechazo de trasplante se puede confundir con una patología oncológica.

The posterior transplant lymph syndrome proliferative disorders include a group of renal lymphoid diseases by definition are present after a solid organ transplant or in bone marrow and are related to immunosuppressive therapy administered. The likelihood of developing a malignancy renal transplant recipient followed over the 17 years is 14 percent for the non-skin cancers, 47 percent in the carcinomas of the skin and 55 percent for any type of cancer. In this work we describes a rare case of a 40 year old patient with chronic renal failure secondary to arterial hypertension in hemodialysis, who underwent cadaveric renal transplant in 2007, the patient presented impaired renal function with palpable mass in right iliac fosse, in treatment with immune suppressants. The histopathology examination of the biopsy reported, posterior transplant with lymphoproliferative disorder with immunohistochemistry positive for CD20, CD79 on B lymphoid cells and CD45 on T lymphoid cells, the extension studies concluding that the mediastinal metastases were: Non-Hodgkin’s lymphoma immunophenotyping B extranodal CD20 + stage IV renal with metastases in the superior mediastinum IPI score May/2009 classified how secondary to high risk renal transplantation. The patient was treated with R-CHOP we obtained a oncology complete response, as demonstrated by CT-PET, and currently free of disease, in nephrology controls. It should monitor any clinical manifestation in the treatment of this kind of patients and served as a rejection of transplant can be confused with metastatic brain tumor.

Transplante renal em pacientes infectados pelo HIV / Kidney transplantation in HIV infected patients

Este artigo de revisão tem como objetivo apresentar as principais considerações sobre o transplante renal em pacientes HIV positivos. Na última década, com o advento da terapia antirretroviral de alta atividade (Highly Active Antiretroviral Therapy - HAART), a evolução dos pacientes infectados pelo vírus da imunodeficiência humana (Human Immunodeficiency Virus - HIV) mudou significativamente, com uma acentuada diminuição das taxas de morbimortalidade nesta população. Neste contexto, o número de pacientes HIV positivos com doença renal crônica com necessidade de terapia dialítica vem aumentando progressivamente. Diante desta nova realidade, o transplante renal, antes considerado uma contraindicação absoluta para tais pacientes, passou a ser considerado uma alternativa de terapia substitutiva da função renal. Questões sobre o uso de imunossupressores neste grupo de pacientes e sua possível ação aumentando a replicação do HIV, além do risco de infecções oportunistas e de desenvolvimento de neoplasias, são amplamente discutidas. Porém, a experiência clínica nessa área mostra que a utilização dessas drogas para pacientes soropositivos parece ser segura, inclusive com relatos de ação antirretroviral de algumas das drogas imunossupressoras. Apesar disso, ainda hoje existem poucos relatos de transplantes nesta população. Em resumo, os dados da literatura sugerem que o transplante renal, seguindo critérios de seleção dos pacientes, parece ser uma alternativa segura como terapia de substituição renal em pacientes HIV positivos.

This review presents current considerations for renal transplantation in HIV patients. In the last decade, with the advent of highly active antiretroviral therapy (HAART), life expectancy of patients infected with human immunodeficiency virus (HIV) has significantly improved, showing a marked decrease in the rates of morbidity and mortality in this population. In this setting, the number of HIV-positive patients with end stage chronic kidney disease requiring dialysis is progressively growing. Kidney transplantation, previously considered as absolute contraindication for HIV-infected patients is currently, in the HAART era, considered a possible treatment alternative. Concerns for the effects of immunosuppressive drugs in these patients and the possible effects on progression of HIV disease, in addition to the risk of opportunistic infections and cancer development are widely discussed. Clinical experience in the HAART era shows that use of immunosuppressive drugs does not adversely affect HIV-seropositive patients. Furthermore, several transplant centers have reported improved patient and graft outcomes for kidney transplant recipients infected with HIV. In summary, results obtained so far are encouraging, supporting that renal transplantation, following specific selection criteria, can be considered an alternative of renal replacement therapy in HIV-infected patients.

B-cell Complement Dependent Cytotoxic Crossmatch Positivity is an Independent Risk Factor for Long-term Renal Allograft Survival

The clinical significance of positive B-cell complement-dependent cytotoxicity crossmatching (B-CDC) in renal transplant recipients remains unclear. We reviewed 20 recipients with isolated B-CDC positivity at the time of transplantation. We compared the clinical characteristics, acute rejection and long-term graft survival between positive and negative B-CDC patients (n = 602). The number of retransplant recipients and positivity for T- and B-flowcytometric crossmatch was greater in positive B-CDC patients than in negative B-CDC patients. The overall acute rejection rate of positive B-CDC patients was significantly higher (P < 0.001), and Banff grade II or III cellular rejection was more frequently observed in positive B-CDC patients (P = 0.037). Compared with negative B-CDC patients, acute cellular rejection as a cause of graft loss was more prevalent (P = 0.020) and rescue rejection therapy was more frequently needed in positive B-CDC patients (P = 0.007). The allograft survival rate of positive B-CDC patients was significantly lower than that of negative B-CDC patients (P < 0.001), and B-CDC positivity independently increased the risk of allograft failure 2.31-fold (95% CI 1.15-4.67; P = 0.019) according to multivariate analysis. In conclusion, isolated B-CDC positivity is an independent long-term prognostic factor for allograft survival.

Atrofia vellositaria duodenal inducida por micofenolato mofetil: caso clínico / Duodenal villous atrophy associated with Mycophenolate mofetil: report of one case

Mycophenolate mofetil (MMF) is an immunosupressor agent frequently used in patients after bone marrow or solid organ transplants. The most common adverse reactions of the drug are gastrointestinal, specially diarrhea and vomiting. We report a 53-year-old male, that received a heart transplant receiving immunosuppression with cyclosporine, mycophenolate mofetil and prednisone. Six months after the transplant, the patient started with diarrhea, anorexia and weight loss. A duodenal biopsy showed villous atrophy. Celiac disease and the presence of parasites were discarded. Mycophenolate mofetil was discontinued and one week later, diarrhea subsided. Two months later the patient was asymptomatic and recovered weight. A new duodenal biopsy showed absence of villous atrophy.

Association of interleukin-10, interferon-gamma, transforming growth factor-beta, and tumor necrosis factor-alpha gene polymorphisms with long-term kidney allograft survival

Single nucleotide polymorphisms within promoter or other regulatory sequences of cytokine genes mainly influence the level of production and secretion of proteins. A large amount of evidence has shown that cytokine gene variations alter graft survival length after kidney transplantation. We studied the association of gene polymorphisms in the interlekin-10 gene [IL10;-1082 G/A], interferon-gamma gene [IFNG; +874 T/A], transforming growth factor-beta gene [TGFB; +869 T/C], and tumor necrosis factor-alpha gene [TNFA;-308 A/G] with kidney allograft survival. The IL10 [-1082 G/A], IFNG [+874 T/A], TGFB [+869 T/C], and TNFA [-308 A/G] genotypes were determined in 32 kidney allograft recipients with graft rejection during the 1st posttransplant year and 52 without rejection in 5 posttransplant years, using allele-specific oligonucleotides-polymerase chain reaction method. The IFNG +874 A/T genotype showed a significantly higher frequency among kidney recipients of the rejection group than the control group [odds ratio, 2.64, 95% confidence interval, 1.03 to 6.74; P=.04]. Comparisons between the rejection and control groups in IL10 [-1082 G/A], IFNG [+874 T/A], TGFB [+869 T/C], and TNFA [-308 A/G] single nucleotide polymorphisms showed no significant difference. Based on the finding of this study, it seems polymorphisms in the genes that regulate IL-10, IFN-gamma, TGF-beta, and TNF-alpha cytokines do not play a major role in kidney allograft survival, and other potential factors in this regard should be considered

Cyclosporine trough levels and its side effects in kidney transplant recipients

Cyclosporine is the backbone of immunosuppression in kidney transplantation. However, it is associated with side effects, some of which are dose-dependent. We evaluated association between cyclosporine trough level and its side effects. In 50 kidney transplant recipients, serum cyclosporine level, fasting blood glucose, and serum creatinine were measured 7 times during first 6 months after transplantation. The participants were also assessed for blood pressure, hand tremor, and headache at each visit. The relationship between cyclosporine trough level and hypertension, hyperglycemia, hand tremor, and headache were evaluated. There were no significant relationship between cyclosporine levels and allograft function. Except at the second week and sixth month, there were no significant differences between drug doses in various serum cyclosporine trough level groups. At the second week, the mean drug dose in patients with cyclosporine trough levels less than the target therapeutic level was 279.16 +/- 56.23 mg/d, while in the patients with cyclosporine levels higher than the therapeutic level, its dose was 302.08 +/- 66.61 mg/d [P < .05]. At the sixth month, the mean drug dose was 137.50 +/- 17.67 mg/d in the patients with lower than target cyclosporine levels, and it was 242.18 +/- 58.25 mg/d in those with cyclosporine levels higher than the therapeutic level [P < .05]. There was no significant relationship between serum cyclosporine level and its side effects. We demonstrated cyclosporine trough level had no direct relation with drug side effects and it is not a suitable measure for assessment of drug side effects

Desensibilización y trasplante renal: plasmaféresis-IVIG a dosis estándar en pacientes con alto riesgo inmunológico / Desensitization and renal transplant: plasmapheresis/IVIG standard dose in patients with high immunological risk

Introducción: Los pacientes con alto riesgo inmunológico siguen siendo relegados a la cada vez más larga lista de espera de un donador inmunológicamente compatible. El objetivo de esta comunicación es informar la experiencia de un centro de trasplantes en la desensibilización de pacientes con alto riesgo inmunológico. Material y métodos: Estudio descriptivo y retrospectivo de todos los pacientes sometidos a trasplante renal de noviembre de 1999 a enero de 2008, en quienes se llevó a cabo desensibilización pretrasplante renal. Resultados: Ocho pacientes presentaron aloinmunización (pruebas cruzadas positivas o panel reactivo de anticuerpos alto, PRA > 30 %). La desensibilización se realizó mediante sesiones de plasmaféresis con recambio de 1.5 volúmenes plasmáticos, y posterior a cada una se administró una dosis estándar de inmunoglubulina intravenosa (IVIG 5 g/dosis). La inmunosupresión se inició en la primera sesión de plasmaféresis con base en un inhibidor de calcineurinas (tacrolimus); en seis pacientes se añadió mofetil micofenolato y en dos, sirolimus. En siete se obtuvieron pruebas cruzadas negativas con el donador previo al trasplante; en el octavo no se efectuaron. En dos se administró anticuerpos humanizados contra CD25 (20 mg/dosis de basiliximab). Todos los pacientes han mantenido función estable del injerto. Conclusiones: De acuerdo con nuestra experiencia, la sobrevida del injerto renal en pacientes con alto riesgo inmunológico posterior a un adecuado protocolo de desensibilización y estrecha vigilancia postrasplante es similar a la observada en pacientes no sensibilizados, al menos durante el primer año del trasplante.

BACKGROUND: Patients with high immunological risk have been relegated to the growing waiting list for an immunologically compatible donor. Our objective was to report the experience of a transplant center in desensitization of patients with high immunological risk. METHODS: We carried out a descriptive and retrospective study. Included were all the renal transplant patients from November 1999 to January 2008 in which we used plasmapheresis and standard dose of intravenous immunoglobulin (IVIG) as desensitization. RESULTS: Eight patients had history of alloimmunity (positive crossmatch or high panel-reactive antibodies (PRA >30%). Desensitization was accomplished with plasmapheresis and exchange of 1.5 plasma volume. Subsequent to each session we administered a standard dose of IVIG (5 g/dose). Immunosuppression began equal to the first plasmapheresis with calcineurin inhibitor (tacrolimus) plus six patients with mycophenolate mofetil and two patients with sirolimus. In seven cases, negative crossmatches were obtained before the transplantation, except in the eighth case in whom it was not done. Two patients received human antibodies against CD25 (basiliximab, 20 mg/dose). During their evolution, all patients maintained stable graft function. CONCLUSIONS: According to our experience, renal graft outcome in patients with high immunological risk after an adequate desensitization protocol is similar to that observed in nonsensitized patients, at least during the first year of transplantation.