Clinical features and genetic biomarkers associated with different phenotypes of systemic lupus erythematosus in Paraguayan patients.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by a heterogeneous clinical picture that makes the diagnosis and follow-up of these patients difficult. This study aimed to identify correlations between clinical, immunological, and genetic biomarkers and clinical manifestations in SLE. A retrospective study of data from medical records and immunological and genetic studies of SLE patients in Paraguay was carried out. A descriptive analysis was performed based on the type of variable. Human leukocyte antigen (HLA) allele frequencies (DPA1, DPB1, DQA1, DQB1, and DRB1) were calculated, and univariate logistic regression analyses were performed between each of the explanatory variables and the presence or absence of each phenotype. Odds ratios, 95% confidence intervals, and p values were recorded. Associations with p<0.05 were considered statistically significant. 104 SLE patients were included: 86% were female, with a mean age of 32.80±10.36 years. An association was identified between anti-double stranded DNA (anti-dsDNA) and the presence of the renal phenotype and between anti-dsDNA and the absence of the joint and hematological phenotypes. Immunoglobulin M isotype rheumatoid factor was associated with the absence of a renal phenotype. HLA-DQB1*02:02 and HLA-DRB1*07:01 were associated with the cutaneous phenotype. An association was identified between age at disease onset over 30 years and the presence of the joint phenotype. No other associations were identified. Potential clinical, immunological, and genetic biomarkers of phenotypes have been identified in SLE Paraguayan patients.

Multisystemic inflammatory syndrome related to COVID-19, with latent tuberculosis in bone marrow, and satisfactory response to tocilizumab, in a 7-year-old boy.

Paediatric inflammatory multisystem syndrome temporally associated with COVID-19 (PIMS-TS) or multisystem inflammatory syndrome in children (MIS-C) is a new acute-onset systemic inflammatory disease, which mainly affects children. Latent tuberculosis infection (LTBI) is characterized by the presence of immune sensitization to Mycobacterium tuberculosis (MTB) in the absence of any clinical or radiological evidence of active disease. We present a child with MIS-C related to COVID-19, with latent TB in the bone marrow, and satisfactory response to tocilizumab. It is important to pay attention in the investigation of TB cases in countries with a high prevalence of tuberculosis, especially when opting for immunusuppression.

Blood platelet adhesion to protein studied by on-line acoustic wave sensor.

The attachment of blood platelets to the surface of bare and protein-coated thickness-shear mode acoustic wave devices operating in a flow-through configuration has been studied. Platelets in washed from bind to the gold electrodes of such sensors, but the resulting frequency shifts are far less than predicted by the conventional mass-based model of device operation. Adherence to albumin and various types of collagen can be produced by on-line introduction of protein or by a pre-coating strategy. Differences in attachment of platelets to collagen types I and IV and the Horm variety can be detected. Platelets attached to collagen yield an interesting delayed, but reversible signal on exposure to a flowing medium of low pH. Scanning electron microscopy of sensor surfaces at various time points in this experiment reveals that originally intact platelets are eventually destroyed by the high acidity of the medium. The reversible frequency is attributed to the presence of removable platelet granular components at the sensor-liquid interface.