Secondary antibody deficiency is associated with development of infection in kidney transplantation: Results of a multicenter study.

Background: We performed a multicenter study to assess the association between secondary antibody deficiency (immunoglobulin G [IgG] hypogammaglobulinemia combined with low levels of specific antibodies) and development of infection in kidney transplantation.

Methods: We prospectively analyzed 250 adult kidney recipients at four centers. The assessment points were before transplantation and 7 and 30 days after transplantation.

Solutions to Avoid False Positives for Rituximab in Pre-Transplant Crossmatches.

Rituximab (anti-CD20) is commonly used as immunotherapy against B cells, in the context of pre-transplant crossmatches, where the presence of rituximab in the tested sera with donor cells can alter their results both by flow cytometry (FCXM) as complement-dependent cytotoxicity (CDCXM) giving rise to false positives. In the present study, we tested the use of an anti-rituximab monoclonal antibody (10C5, Abnova) as a method to avoid false positives in FCXM and CDCXM. We used the serum from ten patients who received therapy with rituximab, and the cells were incubated with sera treated or untreated with the 10C5 clone.

Immunoserologic Detection and Diagnostic Relevance of Cross-Reactive Autoantibodies in Coronavirus Disease 2019 Patients.

Background: During the coronavirus disease 2019 (COVID-19) pandemic, we detected a new immunofluorescence (IF) pattern in serum autoantibody (autoAb) screening of laboratory-confirmed COVID-19 patients.

Methods: The IF pattern was composed of liver and gastric mucosa staining on rat kidney/liver/stomach sections.

Results: We describe 12 patients positive for the cross-reactive antibody, compared with a negative group of 43 hospitalized COVID-19 patients, finding association with either neurologic or thrombotic complications.