B-Cell Responses in Chronic Chagas Disease: Waning of Trypanosoma cruzi-Specific Antibody-Secreting Cells Following Successful Etiological Treatment.

BACKGROUND: A drawback in the treatment of chronic Chagas disease (American trypanosomiasis) is the long time required to achieve complete loss of serological reactivity, the standard for determining treatment efficacy. METHODS: Antibody-secreting cells and memory B cells specific for Trypanosoma cruzi and their degree of differentiation were evaluated in adult and pediatric study participants with chronic Chagas disease before and after etiological treatment. RESULTS: T. cruzi-specific antibody-secreting cells disappeared from the circulation in benznidazole or nifurtimox-treated participants with declining parasite-specific antibody levels after treatment, whereas B cells in most participants with unaltered antibody levels were low before treatment and did not change after treatment. The timing of the decay in parasite-specific antibody-secreting B cells was similar to that in parasite-specific antibodies, as measured by a Luminex-based assay, but preceded the decay in antibody levels detected by conventional serology. The phenotype of total B cells returned to a noninfection profile after successful treatment. CONCLUSIONS: T. cruzi-specific antibodies in the circulation of chronically T. cruzi-infected study participants likely derive from both antigen-driven plasmablasts, which disappear after successful treatment, and long-lived plasma cells, which persist and account for the low frequency and long course to complete seronegative conversion in successfully treated participants.

Miositis viral aguda en un paciente pediátrico con Covid-19: a propósito de un caso / Acute viral myositis in a pediatric patient with Covid-19: about a case

Se presenta el reporte de un caso de miositis aguda en un niño de 4 años de edad con COVID-19. El paciente manifestó fiebre y dolor en ambas pantorrillas. Con sospecha de miositis se realizó análisis de CPK, encontrando valores de 4460 UI/L. Asimismo se realizó hisopado nasofaríngeo para SARS-CoV 2, confirmando la infección. El paciente recibió hiperhidratación, presentando resolución de su cuadro clínico en menos de 5 días

This case report describes a 4 year old child with COVID-19. He presented with fever and pain in both calves. Under the suspicion of myositis a CPK analysis was performed, which showed CPK: 4460 UI/L. Nasopharyngeal RT - PCR was also performed, which was positive. As a treatment, the patient received hyperhydration, achieving full recovery after five days