Differentiating Dengue from COVID-19: Comparison of Cases in Colombia.

The differentiation between dengue and COVID-19 diagnoses is a challenge in tropical regions because of the similarity of symptoms and limited access to specific diagnostic tests for each disease. The objective of this study was to describe the initial symptoms and laboratory test values of patients who presented to the emergency department with dengue or COVID-19. A cross-sectional study was performed in a single center in Cali, Colombia. The inclusion criteria were patients with a diagnosis of dengue or COVID-19 who were older than 14 years of age. All patients experienced fever or other symptoms for fewer than 10 days. Linear regression was performed to evaluate the differences in the neutrophil-lymphocyte ratio (NLR) between patients diagnosed with COVID-19 and dengue, and was adjusted for sex and age group (≤ 31 and > 31 years). The sample size was calculated to test the hypothesis that the median NLR in COVID-19 patients is higher than that in dengue patients. A P value < 0.05 was considered statistically significant for all analyses. A total of 93 patients were included: 70 with dengue and 23 with COVID-19. Dengue patients were younger than COVID-19 patients. There were significant differences between dengue and COVID-19 patients regarding platelet count (P < 0.01), neutrophil count (P < 0.01), NLR (P < 0.01), and abnormal alanine transaminase (ALT) (P = 0.03). The NLR was significantly higher in COVID-19 patients than in dengue patients (P < 0.01). In conclusion, during the first week of symptoms, absolute neutrophil count, NLR, and platelet count could help guide the initial differential approach between dengue and COVID-19. These findings could be useful in geographical areas with a lack of resources.

Simultaneous assessment of rotavirus-specific memory B cells and serological memory after B cell depletion therapy with rituximab.

The mechanisms that contribute to the maintenance of serological memory are still unclear. Rotavirus (RV) memory B cells (mBc) are enriched in IgM(+) and CD27- subpopulations, which are associated with autoimmune diseases pathogenesis. In patients with autoimmune diseases treated with Rituximab (RTX), some autoantibodies (auto-Abs) decrease after treatment, but other auto-Abs and pathogen-specific IgG Abs remain unchanged. Thus, maintenance of autoimmune and pathogen-specific serological memory may depend on the type of antigen and/or Ab isotype evaluated. Antigen-specific mBc and antigen-specific Abs of different isotypes have not been simultaneously assessed in patients after RTX treatment. To study the relationship between mBc subpopulations and serological memory we characterized total, RV- and tetanus toxoid (TT)-specific mBc by flow cytometry in patients with autoimmune diseases before and after treatment with RTX. We also measured total, RV- and TT-Abs, and some auto-Abs by kinetic nephelometry, ELISA, and EliA tests, respectively. Minor differences were observed between the relative frequencies of RV-mBc in healthy controls and patients with autoimmune disease. After RTX treatment, naïve Bc and total, RV- and TT-specific mBc [IgM(+), switched (IgA(+)/IgG(+)), IgM(+) only, IgD(+) only, and CD27- (IgA(+)/IgG(+)/IgM(+))] were significantly diminished. An important decrease in total plasma IgM and minor decreases in total IgG and IgA levels were also observed. IgM rheumatoid factor, IgG anti-CCP, and IgG anti-dsDNA were significantly diminished. In contrast, RV-IgA, RV-IgG and RV-IgG1, and TT-IgG titers remained stable. In conclusion, in patients with autoimmunity, serological memory against RV and TT seem to be maintained by long-lived plasma cells, unaffected by RTX, and an important proportion of total IgM and serological memory against some auto-antigens seem to be maintained by short-lived plasma cells, dependent on mBc precursors depleted by RTX.

Human myeloid dendritic cells treated with supernatants of rotavirus infected Caco-2 cells induce a poor Th1 response.

We have previously shown that human myeloid dendritic cells treated with purified rotavirus induce an allogenic Th1 response. To determine if rotavirus in the context of an intestinal microenvironment modulates the function of dendritic cells, we treated these cells with supernatants from non-infected or infected Caco-2 cells and studied their capacity to promote Th1 or Th2 responses. Dendritic cells treated with supernatants from rotavirus-infected Caco-2 cells promoted a significantly lower Th1 response, in comparison with those treated with purified rotavirus. We wanted to establish if TGF-ß1, induced, or TSLP, not induced, during rotavirus infection, could mediate this effect. Neutralization of TGF-ß but not TSLP in the supernatant prior to treatment of dendritic cells increased their capacity to promote a Th1 response. The results suggest that the TGF-ß1 induced by rotavirus could be an immune evasion mechanism, and may partially explain the poor rotavirus-specific T cell response we have previously evidenced.

Rotavirus-specific B cells induced by recent infection in adults and children predominantly express the intestinal homing receptor alpha4beta7.

In vivo replication of rotaviruses is generally limited to enterocytes. Because of this restriction, most blood circulating rotavirus-specific B cells are hypothesized to originate in Peyer's patches and should express the intestinal homing receptor alpha4beta7. To test this hypothesis in humans, we used a flow cytometry assay that identifies antigen-activated (IgD-) B cells (CD19+) that express surface rotavirus-specific immunoglobulin. With this assay we could detect rotavirus-specific B cells in both children and adults with an acute rotavirus (RV) infection. Staining with an anti-alpha4beta7 monoclonal antibody, we could determine that B cells that express rotavirus-specific surface immunoglobulin predominantly express alpha4beta7. The response of rotavirus-specific antibody-secreting cells in the peripheral blood of children and adults with acute rotavirus infection was also studied by ELISPOT. The antibody-secreting cells of children were mainly of the IgM isotype, while the antibody-secreting cells of adults were predominantly of the IgA and IgG isotype. alpha4beta7+ and alpha4beta7- subsets of peripheral blood mononuclear cells were purified using paramagnetic beads and then tested in the ELISPOT assay. Rotavirus-specific antibody-secreting cells were predominantly present in the alpha4beta7+ subpopulation. The flow cytometry assay we have described will permit future studies to characterize the phenotype of virus-specific B cells and could be useful in the study of the immunogenicity and protective efficacy of RV vaccines and the identification of markers of protective immunity.

II, 11. Human adaptive immunity to rotaviruses: A model of intestinal mucosal adaptive immunity.

This chapter discusses the human adaptive immune response to rotaviruses (RVs), placing the immune response to RVs in the context of the immune response to other mucosal viruses. The chapter discusses the studies of both RV-specific T and B cells. As children with T and/or B immunodeficiencies can develop chronic RV infection, prolonged symptoms, and extraintestinal infection, it is clear that both T and B cells are important for immunity to RV. The various reasons proposed to explain the absence of complete immunity to mucosal viruses such as RV, following primary infection, include a short incubation period after viral exposure, difficulty in maintaining a high level of protective antibody at respiratory and gastrointestinal mucosal surfaces, and a short-lived protective humoral mucosal immune response.

Etiologia, manejo y resultados de la enfermedad obstrtuctiva biliar en el Hospital Universitario del Valle, Cali, Colombia / Etiology, management and results of the obstructive biliary disease in Hospital Universitario del Valle, Cali, Colombia

Se analizaron las historias clinicas de 116 enfermos operados por enfermedad obstructiva del tracto biliar en el ano 1983. El promedio de edad fue 57 anos; 63% eran mayores de 40 anos y las mujeres predominaron sobre los hombres en una relacion de 2.3:1. Los signos y sintomas mas frecuentes fueron nausea, vomito, dolor abdominal en hipocondrio derecho e ictericia. Tan solo se pudo demostrar un patron obstructivo por pruebas de laboratorio en 50% a 60% de los casos. En una proporcion apreciable no se encontraron datos en las historias. La colecistografia oral se la practico en 16% de los casos, la ecografia de la vesicula en 27% y la colangiografia percutanea transparietohepatica en 20%. Lo anterior corrobora que la evaluacion clinica, no obstante las pruebas diagnosticas nuevas, continua como el principal metodo diagnostico. La operacion mas comun fue la colecistectomia mas exploracion de vias biliares. Los germenes aislados con mayor frecuencia fueron escherichia coli, klebsiella pneumoniae y enterobacter cloacae. Se dejo drenaje subhepatico en 21% de los casos. Presentaron complicaciones postoperatorias 45% de los pacientes y las mas comunes fueron shock septico, litiasis residual e infeccion de la herida. Fallecieron 20 pacientes para una mortalidad global del 17.2