Global and cell type-specific immunological hallmarks of severe dengue progression identified via a systems immunology approach.

Severe dengue (SD) is a major cause of morbidity and mortality. To define dengue virus (DENV) target cells and immunological hallmarks of SD progression in children's blood, we integrated two single-cell approaches capturing cellular and viral elements: virus-inclusive single-cell RNA sequencing (viscRNA-Seq 2) and targeted proteomics with secretome analysis and functional assays. Beyond myeloid cells, in natural infection, B cells harbor replicating DENV capable of infecting permissive cells. Alterations in cell type abundance, gene and protein expression and secretion as well as cell-cell communications point towards increased immune cell migration and inflammation in SD progressors. Concurrently, antigen-presenting cells from SD progressors demonstrate intact uptake yet impaired interferon response and antigen processing and presentation signatures, which are partly modulated by DENV. Increased activation, regulation and exhaustion of effector responses and expansion of HLA-DR-expressing adaptive-like NK cells also characterize SD progressors. These findings reveal DENV target cells in human blood and provide insight into SD pathogenesis beyond antibody-mediated enhancement.

Co-Infection between Dengue Virus and SARS-CoV-2 in Cali, Colombia.

The co-occurrence of COVID-19 with endemic diseases is a public health concern that may affect patient prognosis and outcomes. The objective of this study was to describe the clinical characteristics of patients with dengue virus (DENV) and SARS-CoV-2 co-infections and compare their outcomes against those of COVID-19 patients without dengue. A cross-sectional study was conducted in patients with SARS-CoV-2 infection who attended a single center in Cali, Colombia, from March 2020 to March 2021. All patients who were tested by both real-time polymerase chain reaction for SARS-CoV-2 and IgM/NS1 for DENV were included. Dengue was diagnosed as having either an IgM- or an NS1- positive test. A total of 90 patients were included (72 with COVID-19 only and 18 with co-infection). Patients with co-infection had more dyspnea (61.1% versus 22.2%; P = 0.003) as well as higher oxygen desaturation (53.3% versus 13.4%; P = 0.002) and neutrophil-to-lymphocyte ratio (5.59 versus 3.84; P = 0.038) than patients with COVID-19 alone. The proportion of patients classified with moderate to severe COVID-19 was higher in the co-infection group (88.3% versus 47.8%; P = 0.002). Also, co-infection was associated with an increased need for mechanical ventilation (P = 0.06), intensive care unit (ICU) initial management (P = 0.02), and ICU admission during hospitalization (P = 0.04) compared with COVID-19 only. The ICU mortality rate was 66.6% in patients with co-infection versus 29.4% in patients infected with only SARS-CoV-2 (P < 0.05). The possibility of DENV and SARS-CoV2 co-infection occurred in the convergence of both epidemic waves. Co-infection was associated with worse clinical outcomes and higher mortality in ICU-admitted patients than in patients with the COVID-19 only.

Cutaneous tuberculosis as a manifestation of Pott's Disease: A diagnostic challenge in patients with Non-HIV immunosuppression.

Tuberculosis (TB) is one of the most important public health issues in developing countries. The World Health Organization estimates that approximately 20%-40% of the world's population is infected. Pulmonary forms account for the majority of cases; however, it can manifest as extrapulmonary disease in 8.4%-13.7% of cases. Of these extrapulmonary forms of TB, only 1%-2% may have skin manifestations. Cutaneous tuberculosis (CTB) is relatively uncommon and is not a well-defined disease, which complicates diagnosis. We present two patients with Pott's disease that manifested as CTB, one with tuberculous gumma and the other with scrofuloderma. Both patients with non-HIV immunosuppression. The diagnosis of CTB was made by detecting Mycobacterium tuberculosis in skin samples by real-time polymerase chain reaction (Xpert MTB/RIF test) and Ziehl-Neelsen staining. The histologic findings described in these two forms of TB may vary or be absent in immunosuppressed patients, making diagnosis difficult.

Magnitude and kinetics of the human immune cell response associated with severe dengue progression by single-cell proteomics.

Approximately 5 million dengue virus-infected patients progress to a potentially life-threatening severe dengue (SD) infection annually. To identify the immune features and temporal dynamics underlying SD progression, we performed deep immune profiling by mass cytometry of PBMCs collected longitudinally from SD progressors (SDp) and uncomplicated dengue (D) patients. While D is characterized by early activation of innate immune responses, in SDp there is rapid expansion and activation of IgG-secreting plasma cells and memory and regulatory T cells. Concurrently, SDp, particularly children, demonstrate increased proinflammatory NK cells, inadequate expansion of CD16+ monocytes, and high expression of the FcγR CD64 on myeloid cells, yet a signature of diminished antigen presentation. Syndrome-specific determinants include suppressed dendritic cell abundance in shock/hemorrhage versus enriched plasma cell expansion in organ impairment. This study reveals uncoordinated immune responses in SDp and provides insights into SD pathogenesis in humans with potential implications for prediction and treatment.

An 8-gene machine learning model improves clinical prediction of severe dengue progression.

BACKGROUND: Each year 3-6 million people develop life-threatening severe dengue (SD). Clinical warning signs for SD manifest late in the disease course and are nonspecific, leading to missed cases and excess hospital burden. Better SD prognostics are urgently needed. METHODS: We integrated 11 public datasets profiling the blood transcriptome of 365 dengue patients of all ages and from seven countries, encompassing biological, clinical, and technical heterogeneity. We performed an iterative multi-cohort analysis to identify differentially expressed genes (DEGs) between non-severe patients and SD progressors. Using only these DEGs, we trained an XGBoost machine learning model on public data to predict progression to SD. All model parameters were "locked" prior to validation in an independent, prospectively enrolled cohort of 377 dengue patients in Colombia. We measured expression of the DEGs in whole blood samples collected upon presentation, prior to SD progression. We then compared the accuracy of the locked XGBoost model and clinical warning signs in predicting SD. RESULTS: We identified eight SD-associated DEGs in the public datasets and built an 8-gene XGBoost model that accurately predicted SD progression in the independent validation cohort with 86.4% (95% CI 68.2-100) sensitivity and 79.7% (95% CI 75.5-83.9) specificity. Given the 5.8% proportion of SD cases in this cohort, the 8-gene model had a positive and negative predictive value (PPV and NPV) of 20.9% (95% CI 16.7-25.6) and 99.0% (95% CI 97.7-100.0), respectively. Compared to clinical warning signs at presentation, which had 77.3% (95% CI 58.3-94.1) sensitivity and 39.7% (95% CI 34.7-44.9) specificity, the 8-gene model led to an 80% reduction in the number needed to predict (NNP) from 25.4 to 5.0. Importantly, the 8-gene model accurately predicted subsequent SD in the first three days post-fever onset and up to three days prior to SD progression. CONCLUSIONS: The 8-gene XGBoost model, trained on heterogeneous public datasets, accurately predicted progression to SD in a large, independent, prospective cohort, including during the early febrile stage when SD prediction remains clinically difficult. The model has potential to be translated to a point-of-care prognostic assay to reduce dengue morbidity and mortality without overwhelming limited healthcare resources.

Challenges of dengue and coronavirus disease 2019 coinfection: two case reports.

BACKGROUND: Dengue fever and coronavirus disease 2019 have now begun to overlap within tropical and subtropical regions. This is due to the high prevalence of dengue fever in these regions and the current severe acute respiratory syndrome coronavirus 2 pandemic situation. The similarity of symptoms between the two diseases can confuse diagnoses, but coinfection can also occur. CASE PRESENTATION: We present two cases of patients with dengue and severe acute respiratory syndrome coronavirus 2 coinfection. The first case is that of a 24-year-old Hispanic woman with acute fever, odynophagia, and diarrhea, without respiratory symptoms and with positive molecular tests for both dengue and severe acute respiratory syndrome coronavirus 2. The second case is that of a 59-year-old Hispanic male patient with fever and respiratory symptoms of 2 weeks duration, negative molecular tests, and positive serological tests for both viruses. The clinical and epidemiological characteristics of both viral infections can help elucidate diagnoses and prognoses. CONCLUSIONS: Severe dengue infection is common in young adults, while coronavirus disease 2019 is generally asymptomatic. In older people, the severity of dengue fever will depend on their comorbidities or the infectious serotype, but coronavirus disease 2019 is consistently more severe in this group. The accurate diagnosis of both infections can better guide clinical management, as well as public health actions in transmission control, now especially important during the coronavirus disease 2019 pandemic.

Fatal Brucellosis Infection in a Liver Transplant Patient: A Case Report and Review of the Literature.

Brucellosis is the most common zoonosis, particularly in developing countries. The true incidence of human brucellosis is unknown. The WHO points out that 500,000 cases of brucellosis are reported each year from around the world. In Colombia, there is currently no regular surveillance of the event in humans and its prevalence is low due a low clinical suspicion. We report a case of a 66-year-old man, an urban merchant, who had received a liver transplant 11 years ago. The patient presented to the emergency department for two months of fatigue, severe myalgia, paresis of the extremities, loss of muscle strength, and progressive deterioration of functional class. In the emergency room, he became disoriented and was transferred to the intensive-care unit. He had a white blood cell count of 18990/uL and creatine phosphokinase 10302 U/L. Routine blood cultures were positive for Brucella melitensis. The patient reported consumption of unpasteurized bovine milk. He was treated with doxycycline and ciprofloxacin. Despite antibiotic management, after one month of hospitalization and in the context of septic shock with multiorgan failure, the patient died. Brucellosis is an unsuspected and underdiagnosed disease. It can occur in people with or without risk factors. Although the mortality is low, immunocompromised patients can develop fatal infections. A presumptive diagnosis can be established through the correlation of patient history and classic laboratory findings, which include transaminitis, anemia, and leukopenia with relative lymphocytosis; however, other findings can help us to guide the diagnosis, such as rhabdomyolysis, which appears as a complication in different infections; however, it had not been described before in brucellosis. A partnership between clinical suspicion laboratory diagnostic tests and improved disease surveillance systems is necessary to fight the disease.

Transmission of malaria from donors to solid organ transplant recipients: A case report and literature review.

Malaria is a febrile and potentially fatal infection. It is typically transmitted to humans through the bite of Anopheles mosquitoes and less frequently can be contracted through blood transfusions, sharing contaminated needles and syringes, mother-to-child transmission, or after solid organ transplantation. Posttransplant malaria has rarely been reported in the literature, even in endemic areas. We report the cases of three solid organ recipients in which Plasmodium vivax infection was documented during postsurgical evaluation 30 days after transplant surgery. The diagnosis of donor-derived malaria was confirmed in all patients by demonstrating Plasmodium in a peripheral blood smear and by polymerase chain reaction (PCR). All recipients had symptoms. The liver transplant recipient had myalgia, arthralgia, and thrombocytopenia; the kidney transplant recipient developed acute renal failure; and the heart transplant recipient had fever, cephalalgia, and tonic-clonic seizures. Pre-transplant screening of donors and recipients from endemic regions may not be sufficient to safely rule out persistent malaria. In Colombia, according to legislation, no mandatory testing is required for the diagnosis of malaria in organ donors in nonendemic areas. Therefore, donor screening by questionnaire is the only tool for preventing transplant-borne malaria. The migratory trend from Venezuela to Colombia has increased the number of imported cases of malaria, and the infection may be present in endemic and nonendemic regions. Although donor evaluation is not standardized in current guidelines, we suggest that donors be tested for malaria with a peripheral blood smear, detection of specific IgG antibodies against Plasmodium, and techniques such as PCR, if possible.

Disseminated bronchiectasis in an adult with common variable immunodeficiency.

Primary immunodeficiencies (PID) are traditionally considered childhood diseases; however, adults account for 35% of all patients with PID. Antibody deficiencies, especially Common Variable Immunodeficiency (CVID), which have their peak incidence in adulthood, require a high suspicion index. Even though the estimated frequency of CVID is not high (1:25,000), high rates of under diagnosis and under reporting are very likely. The delay in diagnosis increases the morbidity and mortality; therefore, adult physicians should be able to suspect, identify and initiate management of individuals with PID. Here we report the case of a 37 year-old man presenting to the emergency room with dyspnea, fever and cough; he developed respiratory failure requiring mechanical ventilation. He complained of recurring pneumonia associated with widespread bronchiectasis since he was 18 years old. Serum immunoglobulins quantification showed severe hypogammaglobulinemia (total IgG <140 mg/dL; total IgA, 2.9 mg/dL; and total IgM <5 mg/dL). Treatment with Human Intravenous Immunoglobulin (IVIG) 10% was started, and with antibiotic treatment for severe pneumonia (during 14 days) was also prescribed. His clinical evolution has been favorable after one year follow-up. Common Variable Immunodeficiency (CVID) diagnosis was made.

Las inmunodeficiencias primarias (IDP) son patologías que tradicionalmente se consideran de la niñez sin embargo los adultos representan el 35% del total de pacientes con IDP. Las deficiencias de anticuerpos, en especial la Inmunodeficiencia Común Variable (IDCV) tienen su pico de incidencia en la edad adulta, requiere un alto índice de sospecha y si bien su frecuencia estimada no es alta (1:25,000), es muy posible que el subregistro y subdiagnóstico si lo sean. El retraso en el diagnóstico aumenta la morbi-mortalidad razón por la cual los médicos de adultos deben estar en capacidad de sospechar, identificar e iniciar el manejo de las personas con IPD. Presentamos el caso de un hombre de 37 años de edad atendido en la sala de urgencias con disnea, fiebre y tos, desarrolla falla respiratoria requiriendo ventilación mecánica. Refería neumonías a repetición desde los 18 años de edad asociadas con bronquiectasias generalizadas. La cuantificación de inmunoglobulinas séricas evidenció hipogammaglobulinemia severa (IgG total <140 mg/dL, IgA total 2.9 mg/dL, IgM total <5 mg/dL), se inició inmunoglobulina humana endovenosa (IGIV) al 10%, y recibió tratamiento antibiótico por 14 días para neumonía severa, su evolución clínica ha sido favorable hasta ahora (un año de seguimiento), se estableció el diagnostico de Inmunodeficiencia Común Variable (IDCV).

Disseminated bronchiectasis in an adult with common variable immunodeficiency / Bronquiectasias diseminada en un adulto con inmunodeficiencia común variable

Primary immunodeficiencies (PID) are traditionally considered childhood diseases; however, adults account for 35% of all patients with PID. Antibody deficiencies, especially Common Variable Immunodeficiency (CVID), which have their peak incidence in adulthood, require a high suspicion index. Even though the estimated frequency of CVID is not high (1:25,000), high rates of under diagnosis and under reporting are very likely. The delay in diagnosis increases the morbidity and mortality; therefore, adult physicians should be able to suspect, identify and initiate management of individuals with PID. Here we report the case of a 37 year-old man presenting to the emergency room with dyspnea, fever and cough; he developed respiratory failure requiring mechanical ventilation. He complained of recurring pneumonia associated with widespread bronchiectasis since he was 18 years old. Serum immunoglobulins quantification showed severe hypogammaglobulinemia (total IgG <140 mg/dL; total IgA, 2.9 mg/dL; and total IgM <5 mg/dL). Treatment with Human Intravenous Immunoglobulin (IVIG) 10% was started, and with antibiotic treatment for severe pneumonia (during 14 days) was also prescribed. His clinical evolution has been favorable after one year follow-up. Common Variable Immunodeficiency (CVID) diagnosis was made.

Las inmunodeficiencias primarias (IDP) son patologías que tradicionalmente se consideran de la niñez sin embargo los adultos representan el 35% del total de pacientes con IDP. Las deficiencias de anticuerpos, en especial la Inmunodeficiencia Común Variable (IDCV) tienen su pico de incidencia en la edad adulta, requiere un alto índice de sospecha y si bien su frecuencia estimada no es alta (1:25,000), es muy posible que el subregistro y subdiagnóstico si lo sean. El retraso en el diagnóstico aumenta la morbi-mortalidad razón por la cual los médicos de adultos deben estar en capacidad de sospechar, identificar e iniciar el manejo de las personas con IPD. Presentamos el caso de un hombre de 37 años de edad atendido en la sala de urgencias con disnea, fiebre y tos, desarrolla falla respiratoria requiriendo ventilación mecánica. Refería neumonías a repetición desde los 18 años de edad asociadas con bronquiectasias generalizadas. La cuantificación de inmunoglobulinas séricas evidenció hipogammaglobulinemia severa (IgG total <140 mg/dL, IgA total 2.9 mg/dL, IgM total <5 mg/dL), se inició inmunoglobulina humana endovenosa (IGIV) al 10%, y recibió tratamiento antibiótico por 14 dias para neumonía severa, su evolución clínica ha sido favorable hasta ahora (un año de seguimiento), se estableció el diagnostico de Inmunodeficiencia Común Variable (IDCV).

Colecistectomía laparoscópica difícil, estrategias de manejo / Difficult laparoscopic cholecystectomy, management strategies

La colecistectomía laparoscópica es uno de los procedimientos quirúrgicos practicados más frecuentemente por el cirujano general y en un importante número de casos se efectúa en pacientes mayores con gran inflamación vesicular, lo que pone a prueba los conocimientos y habilidades del cirujano. Es perfectamente posible reconocer, antes del acto quirúrgico, en cuáles pacientes este resultará difícil en mayor o menor grado, para así diseñar estrategias de manejo intraoperatorio que nos permitan resolver favorablemente estos casos. En este artículo, el cual se presenta acompañado de videos de casos clínicos publicados en la página electrónica de la Asociación Colombiana de Cirugía (http://www.ascolcirugia.org), se pretende mostrar cuáles son las opciones de manejo en aquellos pacientes cuyas colecistectomías son muy difíciles por el grado de inflamación o por las enfermedades subyacentes y que constituyen alternativas de manejo viables para la colecistectomía laparoscópica clásica o para evitar la conversión a cirugía abierta; aunque también, se llama fuertemente la atención sobre la necesidad de una conversión temprana y oportuna antes de tener complicaciones o alteraciones iatrogénicas de la vía biliar u otro órgano vecino.

Laparoscopic cholecystectomy is one of the most commonly performed procedures by the general surgeon and an important number of cases occur in elderly patients with major inflammation of the gallbladder, a condition that challenges the knowledge and ability of the surgeon. It is perfectible possible to recognize, prior to surgery, which patients will present major or minor difficulties so as to design intraoperative strategies in order to favorably resolve such situations. This article is complemented wit uploaded YouTube videos in the web page of the Asociación Colombiana de Cirugía, http://www.ascolcirugia.org. It intends to show the different management options in those patients with very difficult cholecystectomies because of the degree of inflammation or the underlying pathology that constitute viable alternatives to the classic laparoscopic cholecystectomy or to avoid conversion open surgery; however, it also strongly calls attention to the need of early and timely conversion so as to avoid complications or iatrogenic lesion of the bile duct or neighbor organs.

Acquisition of a multifunctional IgA+ plasma cell phenotype in the gut.

The largest mucosal surface in the body is in the gastrointestinal tract, a location that is heavily colonized by microbes that are normally harmless. A key mechanism required for maintaining a homeostatic balance between this microbial burden and the lymphocytes that densely populate the gastrointestinal tract is the production and transepithelial transport of poly-reactive IgA (ref. 1). Within the mucosal tissues, B cells respond to cytokines, sometimes in the absence of T-cell help, undergo class switch recombination of their immunoglobulin receptor to IgA, and differentiate to become plasma cells. However, IgA-secreting plasma cells probably have additional attributes that are needed for coping with the tremendous bacterial load in the gastrointestinal tract. Here we report that mouse IgA(+) plasma cells also produce the antimicrobial mediators tumour-necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS), and express many molecules that are commonly associated with monocyte/granulocytic cell types. The development of iNOS-producing IgA(+) plasma cells can be recapitulated in vitro in the presence of gut stroma, and the acquisition of this multifunctional phenotype in vivo and in vitro relies on microbial co-stimulation. Deletion of TNF-α and iNOS in B-lineage cells resulted in a reduction in IgA production, altered diversification of the gut microbiota and poor clearance of a gut-tropic pathogen. These findings reveal a novel adaptation to maintaining homeostasis in the gut, and extend the repertoire of protective responses exhibited by some B-lineage cells.

Membrane vesicles released by intestinal epithelial cells infected with rotavirus inhibit T-cell function.

Rotavirus (RV) predominantly replicates in intestinal epithelial cells (IEC), and "danger signals" released by these cells may modulate viral immunity. We have recently shown that human model IEC (Caco-2 cells) infected with rhesus-RV release a non-inflammatory group of immunomodulators that includes heat shock proteins (HSPs) and TGF-ß1. Here we show that both proteins are released in part in association with membrane vesicles (MV) obtained from filtrated Caco-2 supernatants concentrated by ultracentrifugation. These MV express markers of exosomes (CD63 and others), but not of the endoplasmic reticulum (ER) or nuclei. Larger quantities of proteins associated with MV were released by RV-infected cells than by non-infected cells. VP6 co-immunoprecipitated with CD63 present in these MV, and VP6 co-localized with CD63 in RV-infected cells, suggesting that this viral protein is associated with the MV, and that this association occurs intracellularly. CD63 present in MV preparations from stool samples from 36 children with gastroenteritis due or not due to RV were analyzed. VP6 co-immunoprecipitated with CD63 in 3/8 stool samples from RV-infected children, suggesting that these MV are released by RV-infected cells in vivo. Moreover, fractions that contained MV from RV-infected cells induced death and inhibited proliferation of CD4(+) T cells to a greater extent than fractions from non-infected cells. These effects were in part due to TGF-ß, because they were reversed by treatment of the T cells with the TGF-ß-receptor inhibitor ALK5i. MV from RV-infected and non-infected cells were heterogeneous, with morphologies and typical flotation densities described for exosomes (between 1.10 and 1.18 g/mL), and denser vesicles (>1.24 g/mL). Both types of MV from RV-infected cells were more efficient at inhibiting T-cell function than were those from non-infected cells. We propose that RV infection of IEC releases MV that modulate viral immunity.

HLA class II polymorphism in Latin American patients with multiple sclerosis.

OBJECTIVE: To identify HLA-DRB1 alleles contributing to susceptibility to multiple sclerosis (MS) in a Colombian population and to estimate the common effect size of HLA class II on MS susceptibility in Latin American populations through a meta-analysis. METHODS: A total of 65 Colombian patients with MS and 184 matched controls were included. HLA-DRB1 typing was done using the sequence-specific oligonucleotide probe method. A bivariate and a multivariate logistic regression analyses were done. Case-control studies performed in Latin America were searched up to January 2009 through a systematic review of the literature. Effect summary odds ratios (ORs) and 95% confidence intervals (CIs) were obtained by means of the random effect model. RESULTS: A total of 464 cases and 2581 controls from 7 studies and the results of the present study in Colombians were analyzed. HLA-DRB1*15 (OR: 2.3; 95% CI: 1.68-3.07; p<0.001) and HLA-DQB1*06 (OR: 2.2; 95% CI: 1.54-3.07; p<0.001) groups as well as DRB1*1501 (OR: 2.6; 95% CI: 1.67-4.02; p<0.001), DRB1*1503 (OR: 2.2; 95% CI: 1.39-3.62; p=0.001) and DQB1*0602 (OR: 2.5; 95% CI: 1.66-3.71; p<0.001) alleles were found to be risk factors for MS. The myelin basic protein immunodominant sequence (221)VHFFKNIVT(229) was predicted to strongly and simultaneously bind to HLA-DRB1*1501 and *1503. CONCLUSION: The current study highlights the effect size of HLA class II in MS in Latin America and confirms similar allelic risk factors across diverse populations. Receptor-ligand interactions in the HLA-antigenic peptide complex could have potential predictive and therapeutical implications.

Characterization of rotavirus specific B cells and their relation with serological memory.

We quantified circulating total, rotavirus (RV) and Tetanus toxin (TT) memory B cells (mBc) in healthy adults using a limiting dilution assay (LDA) and a flow cytometry assay (FCA) that permit evaluation of both CD27+ and CD27- mBc. RV mBc were enriched in the CD27-, IgG+ and in the CD27+, IgM+ subsets. The numbers of RV mBc were higher by FCA than by LDA and results of the two assays did not correlate. TT IgGmBc and RV IgA mBc determined by FCA and by LDA correlated with TT plasma IgG and RV plasma IgA, respectively. The mean ratio of specific mBc/mug/ml of the corresponding plasma immunoglobulin was lower for TT IgG than for RV IgA mBc. Our studies contribute to understand the relationship between circulating mBc and serological memory, and enhance our capacity to develop better correlates of protection against RV disease.

Evaluation of circulating intestinally committed memory B cells in children vaccinated with attenuated human rotavirus vaccine.

In a double blind trial, 319 fully immunized children received two doses of either placebo or 10(6.7) focus-forming units of the attenuated RIX4414 human rotavirus (RV) vaccine ("all-in-one" formulation). Plasma RV-specific IgA (RV IgA), stool RV IgA, and circulating total and RV memory B cells (CD19+ IgD+/- CD27+) with an intestinal homing phenotype (alpha4beta7+ CCR9+/-) were measured, after the first and second doses, as potential correlates of protection. After the first and/or second dose, 54% of vaccinees and 13% of placebo recipients had plasma RV IgA. Before vaccination, most (95%) of the children (of both study groups) were breast-fed and had stool RV IgA (68.64%). Coproconversion (4-fold increase) after the first and/or second dose was observed in 32.7% of vaccinees and 17.4% of placebo recipients. No significant difference was seen when comparing the frequencies of any subset of memory B cells between vaccinees and placebo recipients. Statistically significant weak correlations were found between plasma RV IgA titers and coproconversion, and several subsets of memory B cells. The vaccine provided 74.8% protection (95% confidence interval, 30.93-92.62) against any RV gastroenteritis and 100% protection (95% confidence interval, 14.53-100) against severe RV gastroenteritis. When vaccinees and placebo recipients were considered together, a correlation was found between protection from disease and plasma RV IgA measured after dose 2 and RV memory (IgD- CD27+ alpha4beta7+ CCR9+) circulating B cells measured after dose 1. However, the correlation coefficients for both tests were low (<0.2), suggesting that other factors are important in explaining protection from disease.

Human rotavirus specific T cells: quantification by ELISPOT and expression of homing receptors on CD4+ T cells.

Using an intracellular cytokine assay, we recently showed that the frequencies of rotavirus (RV)-specific CD4(+) and CD8(+) T cells secreting INFgamma, circulating in RV infected and healthy adults, are very low compared to the frequencies of circulating cytomegalovirus (CMV) reactive T cells in comparable individuals. In children with acute RV infection, these T cells were barely or not detectable. In the present study, an ELISPOT assay enabled detection of circulating RV-specific INFgamma-secreting cells in children with RV diarrhea but not in children with non-RV diarrhea without evidence of a previous RV infection. Using microbead-enriched CD4(+) and CD8(+) T cell subsets, IFNgamma-secreting RV-specific CD8(+) but not CD4(+) T cells were detected in recently infected children. Using the same approach, both CD4(+) and CD8(+) RV-specific T cells were detected in healthy adults. Furthermore, stimulation of purified subsets of PBMC that express lymphocyte homing receptors demonstrated that RV-specific INFgamma-secreting CD4(+) T cells from adult volunteers preferentially express the intestinal homing receptor alpha4beta7, but not the peripheral lymph node homing receptor L-selectin. In contrast, CMV-specific INFgamma-secreting CD4(+) T cells preferentially express L-selectin but not alpha4beta7. These results suggest that the expression of homing receptors on virus-specific T cells depends on the organ where these cells were originally stimulated and that their capacity to secrete INFgamma is independent of the expression of these homing receptors.

Frequencies of virus-specific CD4(+) and CD8(+) T lymphocytes secreting gamma interferon after acute natural rotavirus infection in children and adults.

Human rotavirus-specific CD4(+) and CD8(+) T-cell responses in peripheral blood lymphocytes were studied using a flow cytometric assay that detects the intracellular accumulation of cytokines after short-term in vitro antigen stimulation. The frequencies of virus-specific T cells that secrete gamma interferon and interleukin-13 (IL-13) were determined in adults and children during the acute or convalescent phase of rotavirus-induced diarrhea, in asymptomatically infected adults and laboratory workers who worked with human stool samples containing rotavirus, and in healthy adults. Significantly higher frequencies of rotavirus-specific interferon gamma-secreting CD8(+) and CD4(+) T cells, but not IL-13-secreting T cells, were detected in symptomatically infected adults and exposed laboratory workers than in healthy adults and children with acute rotavirus diarrhea. The levels of rotavirus-specific T cells returned to levels found in healthy adults by 32 days after the onset of rotavirus diarrhea in most adult subjects. Children with rotavirus diarrhea had undetectable or very low levels of CD4(+) and CD8(+) T cells that secrete gamma interferon. Adult cytomegalovirus-seropositive individuals had frequencies of cytomegalovirus-specific T cells that secrete gamma interferon that were approximately 20 times the level of rotavirus-specific T cells. This result suggests that rotavirus is a relatively poor inducer of circulating memory T cells that secrete gamma interferon. The frequencies of gamma interferon-secreting CD4(+) and CD8(+) T cells and the frequencies of IL-13-secreting CD4(+) T cells responding to the T-cell superantigen staphylococcal enterotoxin B (SEB) were lower in children than in adults. In both adults and children, the frequencies of CD4(+) cells secreting gamma interferon in response to SEB were higher than the frequencies of cells secreting IL-13.

Enfermedad vesicular: Diagnostico y tratamiento / Gallblader disease: Diagnosis and treatment

Se revisaron las historias clinicas de 153 pacientes operados en 1983 poe enfermedad vesicular; 61% eran mayores de 40 anos y las mujeres predominaron sobre los hombres en proporcion de 5:1. El sintoma y signo mas frecuente fue el dolor en el cuadrante superior derecho del abdomen. Hubo leucocitosis en 35% de los pacientes e ictericia en 15%. La colecistografia oral, solo, solo se practico a 50% de los enfermos y ecografia a 26.8%. Tenian colecistitis aguda, en sus difernetes formas de presentacion 45% de los pacienteas. A 3% se les extirpo la vesicula siendo normal. La colecistitis acalculosa aparecio en 9.2%. Los germenes mas comunmente aislados fueron Eschericha coli y Klebsiella pneumoniae. Tan solo se dejo un drenaje subhepatico en 5% de los casos. Hubo complicaciones post-operatorios en 13% y las mas frecuentes fueron: infeccion de la herida y litiasis desapercibida en el coledoco. La mortalidad fue 1.3%

Absceso intraabdominal: Estudio de 47 pacientes en el Hospital Universitario del Valle / Intraabdominal abscess: Study of 47 Patients in Hospital Universitario del Valle

Se revisan las historias clinicas de 47 pacientes con absceso intraabdominal intervenidos quirurgicamente en el Hospital Universitario del Valle, entre julio 1 y diciembre 31 de 1984. Casi 66% de los pacientes estaban en el grupo entre 15 y 44 anos de edad. Presentaron leucocitosis 70% de los pacientes e ictericia 15%. Las radiografias simples de abdomen fueron importantes para hacer el diagnostico en 36% de los casos y se encontraron alteraciones en la radiografia de torax en 7%. La ecografia y la gammagrafia se hizo en muy pocos pacientes y a ninguno se le practico TAC