Platelet antibodies identification: comparison between two laboratory tests

ABSTRACT Introduction: Platelet antibody identification is indispensable for diagnosing the human platelet antigen (HPA) or human leukocyte antigen (HLA) immunization, mostly because it can restrict the compatibility and results of transfusions. Correct detection of these antibodies is of utmost importance for the diagnosis and treatment. Method: We present 16 platelet alloimmunization results, comparing two tests with different technologies: the MAIPA (monoclonal antibody immobilization of platelet antigens), as a reference technique, and a bead-based assay, the Pak-Lx. Results: Eleven samples (68.75%) showed agreement in both techniques. Two tests were false negatives in the Pak-Lx: a pan-reactivity in GPIIbIIIa and an anti-HPA-9b. On the other hand, the Pak-Lx was more sensitive to detect a decreasing anti-HPA-5b. The Pak-Lx found an anti-HPA-2b positive, but with a low median fluorescent intensity (MFI), suggesting a false-positive result. Moreover, in one case, the MAIPA was negative for a positive Pak-Lx HLA. Conclusion: Antibody platelet diagnosis can sometimes be challenging. The methods seemed similar, the Pak-Lx being faster and simpler than the MAIPA, and they can be complementary to solve clinical issues.

Aspectos técnicos y clínicos de la prueba cruzada de histocompatibilidad en el trasplante de órganos solidos / Technical and clinical aspects of the histocompatibility crossmatch assay in solid organ transplantation

La presencia de anticuerpos dirigidos contra los antígenos leucocitarios humanos (Human Leukocyte Antigens, HLA) que se expresan en las células del donante, es uno de los factores de riesgo más importantes asociados con las complicaciones clínicas después del trasplante. La prueba cruzada es una de las pruebas de histocompatibilidad más eficaces para la detección de anticuerpos específicos contra el donante en los receptores de injertos. En los primeros métodos de la prueba cruzada, se utilizaba la citotoxicidad dependiente del complemento, que es útil para detectar dichos anticuerpos responsables del rechazo hiperagudo del injerto, pero carece de la sensibilidad adecuada. Por ello, se desarrollaron métodos de pruebas cruzadas más sensibles, entre ellas, la prueba cruzada por citometría de flujo que hoy se considera el método preferido. En este artículo se revisa la evolución de la prueba cruzada y los factores más importantes que deben tenerse en cuenta al realizarla y al interpretar los resultados de esta prueba fundamental para la supervivencia a largo plazo del injerto.

The presence of antibodies directed against human leukocyte antigens (HLA) expressed on donor cells is a significant risk factor for serious clinical complications after transplantation. The crossmatch assay is one of the most important tests available for the detection of donor-specific antibodies in potential allograft recipients. Early crossmatch methods utilized complement-dependent cytotoxicity, which is useful for detecting the donor-specific anti- HLA antibodies responsible for hyperacute allograft rejection but lacks adequate sensitivity. Consequently, more sensitive crossmatch methods have been developed, ultimately leading to the flow cytometry crossmatch as the currently preferred methodology. Herein, we review the evolution of the crossmatch assay and the most important factors to consider when performing and interpreting the results of this fundamental assay for ensuring the long-term survival of the transplanted organ.

Síndrome DRESS inducido por ácido valproico en una niña que respondió a la ciclosporina con análisis de HLA / Valproic acid-induced DRESS in a child responding to cyclosporine with HLA analysis

El síndrome de erupción medicamentosa con eosinofilia y síntomas sistémicos (drug reaction with eosinophilia and systemic symptoms, DRESS), también conocido como síndrome de hipersensibilidad inducida por medicamentos, es una reacción rara potencialmente mortal que causa una erupción grave y que puede provocar insuficiencia multiorgánica. Como con otras erupciones medicamentosas graves, los linfocitos T específicos para un medicamento tienen una función crucial en el síndrome DRESS. El modelo de hapteno/pro-hapteno, el modelo de interacción farmacológica y el modelo alterado de repertorio de péptidos son tres modelos diferentes desarrollados para describir la relación/interacción entre un medicamento o sus metabolitos y el sistema inmunitario. Analizamos nuestra experiencia con el tratamiento con ciclosporina en un caso de síndrome DRESS resistente a esteroides causado por ácido valproico en una niña y sus resultados clínicos, de laboratorio y de antígeno leucocitario humano (HLA).

Drug reaction with eosinophilia and systemic symptoms (DRESS), also known as drug-induced hypersensitivity syndrome, is a potentially life-threatening rare reaction that causes a severe rash and can lead to multiorgan failure. As in other severe drug eruptions, drug-specific T lymphocytes play a crucial role in DRESS. The hapten/pro-hapten model, pharmacological interaction model, and altered peptide repertoire model are three different models developed to describe the relationship/interaction between a medication or its metabolites and the immune system. We discuss our experience with cyclosporine treatment in a steroid-resistant DRESS syndrome caused by valproic acid in a girl, as well as her clinical, laboratory, and human leukocyte antigens (HLA) study results

DNA Methylation and Transcription of HLA-F and Serum Cytokines Relate to Chinese Medicine Syndrome Classification in Patients with Chronic Hepatitis B / 中国结合医学杂志

OBJECTIVE@#To explore the molecular bases of Chinese medicine (CM) syndrome classification in chronic hepatitis B (CHB) patients in terms of DNA methylation, transcription and cytokines.@*METHODS@#Genome-wide DNA methylation and 48 serum cytokines were detected in CHB patients (DNA methylation: 15 cases; serum cytokines: 62 cases) with different CM syndromes, including dampness and heat of Gan (Liver) and gallbladder (CHB1, DNA methylation: 5 cases, serum cytokines: 15 cases), Gan stagnation and Pi (Spleen) deficiency (CHB2, DNA methylation: 5 cases, serum cytokines: 15 cases), Gan and Shen (Kidney) yin deficiency (CHB3, DNA methylation: 5 cases, serum cytokines: 16 cases), CHB with hidden symptoms (HS, serum cytokines:16 cases) and healthy controls (DNA methylation: 6 cases). DNA methylation of a critical gene was further validated and its mRNA expression was detected on enlarged samples. Genome-wide DNA methylation was detected using Human Methylation 450K Assay and furthered verified using pyrosequencing. Cytokines and mRNA expression of gene were evaluated using multiplex biometric enzyme-linked immunosorbent assay (ELISA)-based immunoassay and reverse transcription-quantitative polymerase chain reaction (RT-qPCR), respectively.@*RESULTS@#Totally 28,667 loci, covering 18,403 genes were differently methylated among CHB1, CHB2 and CHB3 (P<0.05 and |Δβ value| > 0.17). Further validation showed that compared with HS, the hg19 CHR6: 29691140 and its closely surrounded 2 CpG loci were demethylated and its mRNA expressions were significantly up-regulated in CHB1 (P<0.05). However, they remained unaltered in CHB2 (P>0.05). Levels of Interleukin (IL)-12 were higher in CHB3 and HS than that in CHB1 and CHB2 groups (P<0.05). Levels of macrophage inflammatory protein (MIP)-1α and MIP-1β were higher in CHB3 than other groups and leukemia inhibitory factor level was higher in CHB1 and HS than CHB2 and CHB3 groups (P<0.05). IL-12, MIP-1α and MIP-1β concentrations were positively correlated with human leukocyte antigen F (HLA-F) mRNA expression (R2=0.238, P<0.05; R2=0.224, P<0.05; R=0.447, P<0.01; respectively). Furthermore, combination of HLA-F mRNA and differential cytokines greatly improved the differentiating accuracy among CHB1, CHB2 and HS.@*CONCLUSIONS@#Demethylation of CpG loci in 5' UTR of HLA-F may up-regulate its mRNA expression and HLA-F expression was associated with IL-12, MIP-1α and MIP-1β levels, indicating that HLA-F and the differential cytokines might jointly involve in the classification of CM syndromes in CHB.@*REGISTRATION NO@#ChiCTR-RCS-13004001.

Analysis of loss of heterozygosity at HLA loci in a patient with leukemia / 中华医学遗传学杂志

OBJECTIVE@#To detect loss of heterozygosity (LOH) at human leukocyte antigen (HLA) loci in a Chinese patient with leukemia after haploidentical hematopoietic stem cell transplantation.@*METHODS@#HLA genotyping was carried out on peripheral blood, hair follicle and buccal swab samples derived from the patient after the transplantation as well as peripheral blood samples from his parents by using PCR-sequence specific oligonucleotide probe method and PCR-sequence based typing method. Short tandem repeat (STR) loci were detected by using a 23 site STR assay kit and a self-developed 6 STR loci assay for the HLA regions.@*RESULTS@#After the transplantation, the HLA genotype of the peripheral blood sample of the patient was identical to his father. The patient was HLA-A*02:01,24:02, C*03:03,03:04, B*13:01,15:01, DRB1*08:03,12:02, DQB1*03:01,06:01 for his hair follicle specimen. However, homozygosity of the HLA loci was found in his buccal swab sample. Only the HLA-A*24:02-C*03:03-B*15:01-DRB1*08:03-DQB1*06:01 haplotype from his father's was present, while the HLA-A*02:01-C*03:04-B*13:01-DRB1*12:02-DQB1*03:01 haplotype from his mother was lost. After the transplantation, the alleles of the 23 STR sites in the patient's peripheral blood sample were consistent to his father, with no allelic loss detected in his buccal swab sample. However, at least 4 STR loci in the HLA region were lost in his buccal swab sample.@*CONCLUSION@#LOH at the HLA loci has been detected in the buccal swab sample of a patient with leukemia who received haploidentical hematopoietic stem cell transplantation.

Generation of genetic modified pigs devoid of GGTA1 and expressing the human leukocyte antigen-G5 / 生物工程学报

Pigs are considered as ideal donors for xenotransplantation because they have many physiological and anatomical characteristics similar to human beings. However, antibody-mediated immunity, which includes both natural and induced antibody responses, is a major challenge for the success of pig-to-primate xenotransplantation. Various genetic modification methods help to tailor pigs to be appropriate donors for xenotransplantation. In this study, we applied transcription activator-like effector nuclease (TALEN) to knock out the porcine α-1, 3-galactosyltransferase gene GGTA1, which encodes Gal epitopes that induce hyperacute immune rejection in pig-to-human xenotransplantation. Meanwhile, human leukocyte antigen-G5 gene HLA-G5, which acts as an immunosuppressive factor, was co-transfected with TALEN into porcine fetal fibroblasts. The cell colonies of GGTA1 biallelic knockout with positive transgene for HLA-G5 were chosen as nuclear donors to generate genetic modified piglets through a single round of somatic cell nuclear transfer. As a result, we successfully obtained 20 modified piglets that were positive for GGTA1 knockout (GTKO) and half of them expressed the HLA-G5 protein. Gal epitopes on the cell membrane of GTKO/HLA-G5 piglets were completely absent. Western blotting and immunofluorescence showed that HLA-G5 was expressed in the modified piglets. Functionally, the fibroblasts from the GTKO/HLA-G5 piglets showed enhanced resistance to complement-mediated lysis ability compared with those from GTKO-only or wild-type pigs. These results indicate that the GTKO/HLA-G5 pigs could be a valuable donor model to facilitate laboratory studies and clinics for xenotransplantation.

A retrospective comparative study of haplotype hematopoietic stem cell transplantation and human leukocyte antigen-matched sibling donor hematopoietic stem cell transplantation in the treatment of acute B-lymphocyte leukemia / 中华血液学杂志

Objective: To investigate whether haplotype hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of pre transplant minimal residual disease (Pre-MRD) positive acute B lymphoblastic leukemia (B-ALL) compared with HLA- matched sibling donor transplantation (MSDT) . Methods: A total of 998 patients with B-ALL in complete remission pre-HSCT who either received haplo-HSCT (n=788) or underwent MSDT (n=210) were retrospectively analyzed. The pre-transplantation leukemia burden was evaluated according to Pre-MRD determinedusing multiparameter flow cytometry (MFC) . Results: Of these patients, 997 (99.9% ) achieved sustained, full donor chimerism. The 100-day cumulative incidences of neutrophil engraftment, platelet engraftment, and grades Ⅱ-Ⅳ acute graft-versus-host disease (GVHD) were 99.9% (997/998) , 95.3% (951/998) , and 26.6% (95% CI 23.8% -29.4% ) , respectively. The 3-year cumulative incidence of total chronic GVHD was 49.1% (95% CI 45.7% -52.4% ) . The 3-year cumulative incidence of relapse (CIR) and non-relapse mortality (NRM) of the 998 cases were 17.3% (95% CI 15.0% -19.7% ) and 13.8% (95% CI 11.6% -16.0% ) , respectively. The 3-year probabilities of leukemia-free survival (LFS) and overall survival (OS) were 69.1% (95% CI 66.1% -72.1% ) and 73.0% (95% CI 70.2% -75.8% ) , respectively. In the total patient group, cases with positive Pre-MRD (n=282) experienced significantly higher CIR than that of subjects with negative Pre-MRD [n=716, 31.6% (95% CI 25.8% -37.5% ) vs 14.3% (95% CI 11.4% -17.2% ) , P<0.001]. For patients in the positive Pre-MRD subgroup, cases treated with haplo-HSCT (n=219) had a lower 3-year CIR than that of cases who underwent MSDT [n=63, 27.2% (95% CI 21.0% -33.4% ) vs 47.0% (95% CI 33.8% -60.2% ) , P=0.002]. The total 998 cases were classified as five subgroups, including cases with negative Pre-MRD group (n=716) , cases with Pre-MRD<0.01% group (n=46) , cases with Pre-MRD 0.01% -<0.1% group (n=117) , cases with Pre-MRD 0.1% -<1% group (n=87) , and cases with Pre-MRD≥1% group (n=32) . For subjects in the Pre-MRD<0.01% group, haplo-HSCT (n=40) had a lower CIR than that of MSDT [n=6, 10.0% (95% CI 0.4% -19.6% ) vs 32.3% (95% CI 0% -69.9% ) , P=0.017]. For patients in the Pre-MRD 0.01% -<0.1% group, haplo-HSCT (n=81) also had a lower 3-year CIR than that of MSDT [n=36, 20.4% (95% CI 10.4% -30.4% ) vs 47.0% (95% CI 29.2% -64.8% ) , P=0.004]. In the other three subgroups, the 3-year CIR was comparable between patients who underwent haplo-HSCT and those received MSDT. A subgroup analysis of patients with Pre-MRD<0.1% (n=163) was performed, the results showed that cases received haplo-HSCT (n=121) experienced lower 3-year CIR [16.0% (95% CI 9.4% -22.7% ) vs 40.5% (95% CI 25.2% -55.8% ) , P<0.001], better 3-year LFS [78.2% (95% CI 70.6% -85.8% ) vs 47.6% (95% CI 32.2% -63.0% ) , P<0.001] and OS [80.5% (95% CI 73.1% -87.9% ) vs 54.6% (95% CI 39.2% -70.0% ) , P<0.001] than those of MSDT (n=42) , but comparable in 3-year NRM [5.8% (95% CI 1.6% -10.0% ) vs 11.9% (95% CI 2.0% -21.8% ) , P=0.188]. Multivariate analysis showed that haplo-HSCT was associated with lower CIR (HR=0.248, 95% CI 0.131-0.472, P<0.001) , and superior LFS (HR=0.275, 95% CI 0.157-0.483, P<0.001) and OS (HR=0.286, 95% CI 0.159-0.513, P<0.001) . Conclusion: Haplo HSCT has a survival advantage over MSDT in the treatment of B-ALL patients with pre MRD<0.1% .

Inmunización feto materna contra antígenos de HLA en mujeres de una población paraguaya / Fetomaternal immunization against HLA antigens in women from a Paraguayan population

El embarazo es la única causa natural de inmunización contra el sistema de Antígenos Leucocitarios Humano (HLA). Durante la gestación hay paso de leucocitos fetales a través de la placenta, lo que puede desencadenar en la madre una respuesta inmunológica contra los antígenos HLA fetales de origen paterno, con la consecuente producción de anticuerpos. El objetivo del estudio fue conocer la prevalencia de sensibilización a antígenos HLA inducida por embarazos en mujeres paraguayas y estudiar las características y especificidades de los anticuerpos encontrados. Realizamos un estudio descriptivo, prospectivo, de corte transversal de 319 mujeres paraguayas, que acudieron al Laboratorio Central de Salud Pública entre abril de 2017 y abril de 2018 utilizando la tecnología LUMINEX para la detección de anticuerpos anti- HLA. Se encontraron anticuerpos anti-HLA en 46% de las mujeres multíparas. Se detectaron anticuerpos contra todos los antígenos testados. La gran mayoría de los sueros resultaron ser poliespecíficos. Concluimos que al aumentar el número de gestas no solo aumenta la probabilidad de una mujer de desarrollar anticuerpos anti- HLA, sino que también parece aumentar la cantidad de especificidades desarrolladas y el título de los anticuerpos

Pregnancy is the only natural cause of immunization against the Human Leukocyte Antigen (HLA) system. During pregnancy, fetal leukocytes pass through the placenta, which can trigger an immunological response in the mother against the fetus paternal HLA antigens, with the consequent production of antibodies. The objective of this study was to determine the prevalence of pregnancy-induced HLA antigen sensitization in Paraguayan women and to study the characteristics and specificities of the antibodies found. We conducted a descriptive, prospective, cross-sectional study of 319 Paraguayan women, who attended the Central Laboratory of Public Health between April 2017 and April 2018 using LUMINEX technology to detect anti-HLA antibodies. We found anti-HLA antibodies in 46% of multiparous women. Antibodies against all tested antigens were detected. The vast majority of the sera exhibited multiple specificities. We conclude that increasing the number of gestations not only increases a woman's likelihood of developing anti-HLA antibodies, but it also appears to increase the number of developed specificities and titers of antibodies

Progress in study on the association between HLA genetic variation and adverse drug reactions / 中南大学学报(医学版)

The human leukocyte antigen (HLA) molecules encoded within the human major histocompatibility complex are a group of highly conserved cell surface proteins, which are related to antigen recognition. HLA genes display a high degree of genetic polymorphism, which is the basis of individual differences in immunity. Specific HLA genotypes have been highly associated with typical adverse drug reactions. HLA-A*31:01 and HLA-B*15:02 are associated with carbamazepine-induced severe cutaneous adverse reactions, HLA-B*57:01 is related to abacavir-induced drug-induced hypersensitivity syndrome and flucloxacillin/pazopanib-induced drug-induced liver injury, while HLA-B*35:01 is a potential biomarker for predicting polygonum multiflorum-induced liver injury. It is not clear how small drug molecules to interact with HLA molecules and T cell receptors (TCR). There are four mechanistic hypotheses, including the hapten/prohapten theory, the pharmacological interaction concept, the altered peptide repertoire model, and the altered TCR repertoire model.

Early stage of antibody-mediated rejection after lung transplantation： A case report and literature review / 中南大学学报(医学版)

Antibody-mediated rejection (AMR) is a rare and serious complication after lung transplantation, with no characteristic of pathological manifestation, no systematic standard treatment, and the poor efficacy and prognosis. We reported a case of early AMR after lung transplantation and the relevant literature has been reviewed. A male patient presented with symptoms of cold 99 days after transplantation and resolved after symptomatic treatment. He admitted to the hospital 14 days later because of a sudden dyspnea and fever. Anti-bacteria, anti-fungi, anti-virus, and anti-pneumocystis carinii treatment were ineffective, and a dose of 1 000 mg methylprednisolone did not work too. The patient's condition deteriorated rapidly and tracheal intubation was done to maintain breathing. Serum panel reactive antibody and donor specific antibody showed postive in humen leukocyte antigen (HLA) II antibody. Pathological examination after transbronchial transplantation lung biopsy showed acute rejection. Clinical AMR was diagnosed combined the donor-specific antibody with the pathological result. The patient was functionally recovered after combined treatment with thymoglobuline, rituximab, plasmapheresis, and immunoglobulin. No chronic lung allograft dysfunction was found after 3 years follow up. We should alert the occurrence of AMR in lung transplantation recipient who admitted to hospital with a sudden dyspnea and fever while showed no effect after common anti-infection and anti-rejection treatment. Transbronchial transplantation lung biopsy and the presence of serum donor-specific antibody are helpful to the diagnosis. The treatment should be preemptive and a comprehensive approach should be adopted.

Outcomes of haploidentical bone marrow transplantation in patients with severe aplastic anemia-II that progressed from non-severe acquired aplastic anemia / 医学前沿

Severe aplastic anemia II (SAA-II) progresses from non-severe aplastic anemia (NSAA). The unavailability of efficacious treatment has prompted the need for haploidentical bone marrow transplantation (haplo-BMT) in patients lacking a human leukocyte antigen (HLA)-matched donor. This study aimed to investigate the efficacy of haplo-BMT for patients with SAA-II. Twenty-two patients were included and followed up, and FLU/BU/CY/ATG was used as conditioning regimen. Among these patients, 21 were successfully engrafted, 19 of whom survived after haplo-BMT. Four patients experienced grade II-IV aGvHD, including two with grade III-IV aGvHD. Six patients experienced chronic GvHD, among whom four were mild and two were moderate. Twelve patients experienced infections during BMT. One was diagnosed with post-transplant lymphoproliferative disorder and one with probable EBV disease, and both recovered after rituximab infusion. Haplo-BMT achieved 3-year overall survival and disease-free survival rate of 86.4% ± 0.73% after a median follow-up of 42 months, indicating its effectiveness as a salvage therapy. These promising outcomes may support haplo-BMT as an alternative treatment strategy for patients with SAA-II lacking HLA-matched donors.

Donor-specific antibodies, glomerulitis, and human leukocyte antigen B eplet mismatch are risk factors for peritubular capillary C4d deposition in renal allografts / 中华医学杂志(英文版)

BACKGROUND@#The complement system plays an important role in the immune response to transplantation, and the diagnostic significance of peritubular capillary (PTC) C4d deposition (C4d+) in grafts is controversial. The study aimed to fully investigate the risk factors for PTC C4d+ and analyze its significance in biopsy pathology of kidney transplantation.@*METHODS@#This retrospective study included 124 cases of kidney transplant with graft biopsy and donor-specific antibody (DSA) testing from January 2017 to December 2019 in a single center. The effects of recipient pathological indicators, eplet mismatch (MM), and DSAs on PTC C4d+ were examined using univariate and multivariate logistic regression analyses.@*RESULTS@#In total, 35/124 (28%) were PTC C4d+, including 21 with antibody-mediated rejection (AMR), eight with renal tubular injury, three with T cell-mediated rejection, one with glomerular disease, and two others. Univariate analysis revealed that DSAs (P < 0.001), glomerulitis (P < 0.001), peritubular capillaritis (P < 0.001), and human leukocyte antigen (HLA) B eplet MM (P = 0.010) were the influencing factors of PTC C4d+. According to multivariate analysis, DSAs (odds ratio [OR]: 9.608, 95% confidence interval [CI]: 2.742-33.668, P < 0.001), glomerulitis (OR: 3.581, 95%CI: 1.246-10.289, P = 0.018), and HLA B eplet MM (OR: 1.166, 95%CI: 1.005-1.353, P = 0.042) were the independent risk factors for PTC C4d+. In receiver operating characteristic curve analysis, the area under the curve was increased to 0.831 for predicting PTC C4d+ when considering glomerulitis, DSAs, and HLA B eplet MM. The proportions of HLA I DSAs and PTC C4d+ in active antibody-mediated rejection were 12/17 and 15/17, respectively; the proportions of HLA class II DSAs and PTC C4d+ in chronic AMR were 8/12 and 7/12, respectively. Furthermore, the higher the PTC C4d+ score was, the more serious the urinary occult blood and proteinuria of recipients at the time of biopsy.@*CONCLUSIONS@#PTC C4d+ was mainly observed in AMR cases. DSAs, glomerulitis, and HLA B eplet MM are the independent risk factors for PTC C4d+.

Frequency of alleles associated with celiac disease in patients with autoimmune thyroid disease / Frequência dos alelos associados com a doença celíaca em portadores de doenças autoimunes da tireoide

ABSTRACT Objective To determine the frequency of Human leukocyte antigen alleles and to verify the association of the presence of these alleles with symptoms and other diseases related to celiac disease in patients with autoimmune thyroid diseases. Methods A questionnaire on the symptoms and diseases associated with celiac disease was applied. Genomic deoxyribonucleic acid was extracted by collecting cells from the oral mucosa. The alleles (DQA1*0501; DQB1*0201; DRB1*04) were identified by means of the polymerase chain reaction. Results A total of 110 patients with autoimmune thyroid diseases participated in this study. It was observed that 66.4% of the individuals carried at least one of the alleles assessed and that 58.2% of the individuals were positive for at least one of the DQ2 alleles (DQA1*0501; DQB1*0201) and out of these 18.2% were positive for both DQ2 alleles (DQA1*0501; DQB1*0201). With regard to DQ8 (DRB1*04), 21.8% of the studied population was positive for this allele and 3.6% was positive for both DQ2 (DQA1*0501; DQB1*0201) and DQ8 (DRB1*04). A significant association was found between the presence of the DRB1*04 allele and gastrointestinal symptoms (p=0.02). A significant association of the DRB1*04 allele with type 1 diabetes mellitus (p=0.02) was observed. Conclusion The genetic profiles most commonly associated with celiac disease, such as DQ2 (DQA1*0501; DQB1*0201) and DQ8 (DRB1*04) were around 20.0% prevalent in the studied population. These are risk haplotypes for celiac disease especially when symptoms and diseases related to celiac disease are present. Therefore, it is important to screen patients to investigate a potential diagnosis for celiac disease.

RESUMO Objetivo Determinar a frequência dos alelos do Human leukocyte antigen e verificar a associação da presença desses alelos com sintomas e outras doenças relacionados à doença celíaca em portadores de doenças autoimunes da tireoide. Métodos Aplicou-se um questionário relacionado aos sintomas e doenças associados à doença celíaca. O ácido desoxirribonucleico genômico foi extraído por meio da coleta das células da mucosa bucal. Os alelos (DQA1*0501; DQB1*0201; DRB1*04) foram identificados por meio da reação em cadeia da polimerase. Resultados Participaram deste estudo 110 portadores de doenças autoimunes da tireoide. Observou-se que 66,4% dos indivíduos carregavam pelo menos um dos alelos estudados e que 58,2% dos indivíduos eram positivos para pelo menos um dos alelos DQ2 (DQA1*0501; DQB1*0201) e destes 18,2% foram positivos para ambos alelos do DQ2(DQA1*0501; DQB1*0201). Com relação ao DQ8 (DRB1*04), 21,8% da população estudada eram positivos para esse alelo e 3,6% eram positivos tanto para o DQ2 (DQA1*0501; DQB1*0201) quanto para o DQ8 (DRB1*04). Foi encontrada associação significativa da presença do alelo DRB1*04 com os sintomas gastrointestinais (p=0,02). Houve associação significativa do alelo DRB1*04 com diabetes mellitus tipo 1 (p=0,02). Conclusão O perfil genético mais fortemente associado à doença celíaca, tais como DQ2 (DQA1*0501; DQB1*0201) e DQ8 (DRB1*04) estavam presentes em torno de 20,0% da população estudada, estes são haplótipos de risco para doença celíaca e principalmente na presença de sintomas e doenças relacionadas à doença celíaca. Sendo assim, é importante realizar o rastreamento para investigar um possível diagnóstico para doença celíaca.

Neutropenia aloimune neonatal em gêmeas idênticas / Neonatal alloimmune neutropenia in identical twins

A neutropenia aloimune neonatal (NAN) é uma patologia causada pelo antagonismo imunológico, como a doença hemolítica do recém-nascido ou a trombocitopenia aloimune neonatal, mas relacionada aos neutrófilos, em vez de glóbulos vermelhos ou plaquetas. Descreveremos um caso clínico de duas gêmeas idênticas nascidas a termo, com Apgar de 8 e 9, sendo que após algumas horas do nascimento apresentaram febre. Um exame de sangue revelou neutropenia grave que resultou em sepse. O diagnóstico da NAN foi realizado clinicamente e por testes de histocompatibilidade. A prova cruzada por citometria de fluxo foi positiva, usando soro da mãe e suspensões celulares (granulócitos e linfócitos) das gêmeas e do pai. Este teste não fornece informações sobre para qual sistema genético os anticorpos foram positivos, se contra os antígenos específicos de neutrófilos humanos (HNA) ou contra os antígenos leucocitários humanos (HLA). Para o esclarecimento, realizamos o teste de aglutinação de granulócitos (GAT) com um painel de doadores fidelizados e com antígenos HNA1-5 conhecidos, utilizando o soro materno como reagente. Foi também realizada a pesquisa de anticorpos anti-HLA e anti-HNA no soro materno. Os genótipos HLA e HNA foram identificados, permitindo conhecer as especificidades dos anticorpos maternos contra os antígenos dos neutrófilos do marido e das filhas. O diagnóstico de NAN não é realizado na maioria dos hospitais de nosso país e do exterior, devido à dificuldade de execução dos testes de histocompatibilidade, no entanto a prova cruzada por citometria de fluxo pode facilmente ser implantada nos laboratórios clínicos, sendo que está descrita detalhadamente nesse caso clínico.

Neonatal alloimmune neutropenia (NAN) is a disease caused by immunological antagonism, such as hemolytic disease of the newborn or neonatal alloimmune thrombocytopenia, but related to neutrophils rather than to red blood cells or platelets. We will describe a clinical case of two identical twins born with Apgar 8 and 9 that started with fever few hours after delivery. A blood test revealed severe neutropenia, which was followed by sepsis. The diagnosis of NAN was done clinically and by histocompatibility testing. Flow cytometry crossmatch was positive, using mother serum and cell suspensions (granulocytes and lymphocytes) from the twin girls and from the father. This test did not provide information about the genetic system for which the antibodies are positive, if against human neutrophil antigens (HNA) or human leucocyte antigens (HLA). To clear this, the granulocyte agglutination test (GAT) was performed with a panel of control donors with known HNA1-5 antigens, using the maternal serum as a reagent. We did also a Luminex screening assay for detection of anti-HLA and anti-HNA antibodies in the mother serum. The HLA and HNA genotypes were identified, which allowed to define specificities in mother's antibodies against the neutrophil surface antigens from her husband and from the twins. The diagnosis of NAN diagnose is not done in most hospitals worldwide, mainly by the difficulty in executing the histocompatibility test. However, the crossmatch by flow cytometry could be easily done in clinical laboratories following the method described in this article.

Renal transplant patients with preformed anti-HLA antibodies: early biopsy findings and clinical outcomes / Pacientes transplantados renais com anticorpos anti-HLA pré-formados: achados precoces de biópsia e desfechos clínicos

Abstract Introduction: Renal fibrosis is the end point of a process that begins at transplant, with ischemia reperfusion and early inflammation, and progresses over time with immunological and non-immunological phenomena. Early identification of morphological markers and intervention could improve graft function and survival. Objective: to evaluate the correlation between intensity and specificity of pre-transplant anti-HLA antibodies and kidney allograft pathology in order to identify early risk factors or markers of allograft dysfunction. Methods: A retrospective cohort of kidney transplant recipients with pre-transplant anti-HLA antibodies who underwent graft biopsy within the first two years post-transplant was divided into two groups according to the specificity of anti-HLA antibodies: nonspecific (non-DSA, n = 29) and specific (DSA+, n = 16). Kidney graft pathology, renal function, and proteinuria were analyzed. Results: general characteristics were similar in both groups, except for the higher dose of thymoglobulin in DSA+ group (p < 0.05). The non-DSA group had higher scores for glomerulosclerosis, interstitial inflammation (i) and interstitial fibrosis (ci) (p < 0.05) and higher incidence of cell-mediated acute rejection. No statistical difference in incidence of antibody-mediated rejection, renal function, and proteinuria was observed during follow up. Discussion and conclusions: the difference in inflammation scores and interstitial fibrosis may be associated to the higher incidence of acute cell-mediated rejection and polyomavirus nephropathy in the Non-DSA group. We also should take into account the protective effect of higher doses of thymoglobulin, reducing ischemia reperfusion injury in the DSA+ group. The short follow-up might have been insufficient to detect long-term changes in allograft tissue, renal function, and proteinuria.

Resumo Introdução: A fibrose renal é o desfecho de um processo iniciado no transplante, com reperfusão, isquemia e inflamação precoce, que progride ao longo do tempo com fenômenos imunológicos e não imunológicos. A identificação de marcadores morfológicos e a intervenção precoce poderiam melhorar a função e a sobrevida do enxerto. Objetivo: Avaliar a correlação entre intensidade e especificidade de anticorpos anti-HLA pré-transplante alterações histológicas do enxerto renal, de forma a identificar fatores de risco ou marcadores de disfunção precoces do aloenxerto. Métodos: O presente estudo incluiu uma coorte retrospectiva de receptores de transplante renal sensibilizados com anticorpos anti-HLA no pré-transplante submetidos a biópsia de enxerto nos primeiros dois anos após o transplante. Os grupos foram divididos em função da especificidade dos anticorpos anti-HLA: sem anticorpos doador-específicos (não-DSA, n = 29) e com anticorpos doador-específicos (DSA+, n = 16). Alterações histológicas do enxerto renal, função renal e proteinúria foram analisados. Resultados: Os dois grupos tinham características gerais semelhantes, exceto pela dose mais elevada de timoglobulina administrada nos indivíduos do grupo DSA+ (p < 0,05). O grupo não-DSA teve escores mais elevados de glomeruloesclerose, inflamação intersticial (i) e fibrose intersticial (ci) (p < 0,05), além de maior incidência de rejeição celular aguda (RCA). Não foi observada diferença estatística na incidência de rejeição mediada por anticorpos, função renal ou proteinúria durante o seguimento. Discussão e Conclusões: A diferença nos escores de inflamação e fibrose intersticial pode estar associada à maior incidência de RCA e nefropatia por poliomavírus no grupo não-DSA. Devemos considerar ainda o efeito protetor das doses mais elevadas de timoglobulina na redução da lesão por isquemia-reperfusão no grupo DSA+. O curto período de seguimento pode ter sido insuficiente para detectar alterações de longo prazo no tecido do aloenxerto, função renal e proteinúria.

Peripheral blood stem cell transplantation from HLA-mismatched unrelated donor or haploidentical donor for the treatment of X-linked agammaglobulinemia / 中国当代儿科杂志

Allogeneic stem cell transplantation (allo-SCT) is currently the only curative option for patients with X-linked agammaglobulinemia (XLA). In this study, patient 1 aged 4 years who underwent allogeneic peripheral blood stem cell transplantation (allo-PBSCT) from HLA-mismatched unrelated donor; patient 2 aged 24 years (childhood onset) with primary cutaneous acral CD8 T cell lymphoma who underwent allo-PBSCT from haploidentical relative donor. Both were treated by reduced toxicity myeloablative conditioning with post-transplantation cyclophosphamide (PTCy), anti-thymocyte globulin (ATG), methotrexate (MTX) and cyclosporine (CsA) for graft-versus-host-disease (GVHD) prophylaxis. In patient 1, neutrophil and platelet engraftment were observed on day 11 post-transplantation; the donor chimerism dropped on day 90 post-transplantation, and recovered on day 150 with donor lymphocyte infusion (DLI). In patient 2, neutrophil and platelet engraftment were observed on days 20 and 87 post-transplantation respectively, with complete donor chimerism on day 30 post-transplantation. The serum levels of IgG, IgM and IgA and the percentage of CD19 B cells in peripheral blood of patients 1 and 2 returned to normal within 2 months and more than 1 year after transplantation respectively. There was no evidence of acute GVHD for the two patients. Patient 1 developed a limited type of skin chronic GVHD after DLI, which disappeared after anti-GVHD treatment. This is the first report of successful treatment for two XLA patients using PTCy with allo-PBSCT from HLA-mismatched unrelated donor or haploidentical donor, combining with improved conditioning, which expands the pool of eligible donors for patients with XLA.

Alelos HLA más comunes y asociados con riesgo o protección en enfermedad renal crónica de etiología no determinada / Most common HLA alleles associated with risk or protection in chronic kidney disease of undetermined etiology

Resumen Introducción: La enfermedad renal crónica representa parte del gasto en salud en general; una potencial etiología es la relacionada con variaciones, ausencia o presencia de algunos alelos del human leucocyte antigen (HLA). Método: Se realizó el análisis de 1965 reportes de HLA sin etiología determinada y de 1361 donadores renales. Se llevó a cabo tecnología Luminex con base en fluorimetría de flujo celular para los locus A, B, DRB1 y DQA. Se realizó análisis con tablas de contingencia para determinar razón de momios (RM) e intervalos de confianza (IC). Se efectuó análisis cuantitativo. Resultados: De 101 alelos encontrados, 13 presentaron asociación, siete con riesgo para enfermedad renal crónica, de los cuales el más significativo fue HLA-DR17, con RM = 3.91 (IC 95 % = 2.96-5.17), y el de mayor significación de protección fue HLA-DR9, con RM = 0.043 (IC 95 % = 0.005-0.3224). Conclusiones: Es necesario entender que las enfermedades renales pueden estar ligadas a procesos inmunológicos, en los que se tiene que conocer la asociación de la ausencia o presencia de algún alelo.

Abstract Introduction: Chronic kidney disease accounts for part of overall health expenditure; a potential etiology is related to variations, absence or presence of some human leukocyte antigen (HLA) alleles. Method: An analysis of HLA reports of 1965 kidney recipients with no determined etiology, and 1361 kidney donors was performed. It was carried out with Luminex based in cell flow fluorometry for the A, B, DRB1 and DQA loci. An analysis was performed with contingency tables in order to determine the odds ratio (OR) and confidence intervals (CI). Quantitative analysis was also carried out. Results: Of the 101 alleles found, 13 showed association, 7 with risk for chronic kidney disease, with the most significant being HLA-DR17 with an OR of 3.91 (95 % CI = 2.96-5.17) and the one with the highest significance for protection being HLA-DR9, with an OR of 0.043 (95 % CI = 0.005-0.3224). Conclusions: It is necessary to understand that kidney diseases can be associated with yet unknown immune processes, where the association of the absence or presence of any allele should be known.