B Cell Subgroups as Potential Biomarkers in Predominantly Antibody Deficiencies with Complications

Predominantly antibody deficiencies (PADs) are the most prevalent primary immunodeficiencies that are caused by genetic disorders and result in impairment of the immune system. Therefore, PAD diagnosis has been extensively studied, yet their B-cell defects and underlying genetic alterations remain largely unknown. The aim of this study is to determine the immunological differences in PAD patients categorized by patients showing different complications such as splenomegaly, bronchiectasis, and chronic diarrhea.

A total of 45 participants, consisting of 27 patients diagnosed with PAD and 18 healthy control individuals were included in this study. The relationship between B cell subgroups in PAD patients and control groups are investigated. Additionally, the association between B cell subgroups and complications such as splenomegaly, bronchiectasis, and chronic diarrhea in PAD patients are studied.

In this study, we found an association between splenomegaly and various B cell subgroups such as naive B cells, CD21low B cells, and SW memory B cells. In the correlation analysis, we found a negative correlation between naive B cells and splenomegaly. Additionally, to the best of our knowledge, this study is the first to show a statistically significant association between memory B cells and chronic diarrhea as well as between transitional B cells and bronchiectasis.

This study provides biomarkers to predict PAD patients' clinical progression or disease complications.