Renal Complications in Patients with Predominant Antibody Deficiency in the United States Immune Deficiency Network (USIDNET)

Background Prior studies have reported that renal insufficiency occurs in a small percentage of patients with predominantly antibody deficiency (PAD) and in about 2% of patients with common variable immunodeficiency (CVID). Objective The goal of our study was to understand and evaluate the prevalence and type of renal complications in PAD patients in the United States Immunodeficiency Network (USIDNET) cohort. We hypothesized there is an association between certain renal complications and severity of immunophenotype in patients with PAD. Methods We performed a query of patients with PAD from the USIDNET cohort with renal complications. Patients with documented renal disease such as chronic kidney disease (CKD), nephrolithiasis, nephritis, and renal failure syndrome were included. We compared immunophenotype, flow cytometry and immunoglobulin (Ig) levels of PAD patients with renal complications to the total PAD USIDNET cohort. Results We identified that 140/2071 (6.8%) of PAD patients had renal complications. Of these 50 (35.7%) had CKD, 46 (32.9%) had nephrolithiasis, 18 (12.9 %) had nephritis, and 50 (35.7%) had other renal complications. Compared to the total USIDNET cohort of patients with PAD, patients with CKD had lower ALCs, CD3+ T-cells, CD4+ T-cells, CD19+ B-cells, CD20+ B-cells and CD27+IgD- B-cells (p<0.05 for all). Patients with nephritis had lower ALCs, CD19+ B-cells, CD27+ B-cells and IgE levels (p<0.05 for all) compared to PAD patients without renal disease. Conclusions We identified that 6.8% of PAD patients in the USIDNET cohort had a documented renal complication. The patients with nephritis and CKD had a more severe immunophenotype compared to the overall PAD cohort.