Evaluation of cellular and humoral autoimmunity before the development of type 1 diabetes in a patient with idiopathic CD4 lymphocytopenia

Abstract

Abstract A 64‐year‐old woman developed type 1 diabetes 23 years after the diagnosis of idiopathic CD4 lymphocytopenia. To investigate the etiological interaction between idiopathic CD4 lymphocytopenia and type 1 diabetes, we carried out a longitudinal analysis related to islet‐specific autoimmunity. Anti‐glutamic acid decarboxylase antibody had been already weakly positive for at least 16 years and started rising at 6 months before the onset of type 1 diabetes. The seroconversion of anti‐insulinoma‐associated antigen‐2 antibody and insulin autoantibody occurred at the time of onset. The ratio of CD8/CD4 had been gradually increasing for 8 years before type 1 diabetes onset. Notably, islet‐specific glucose‐6‐phosphatase catalytic subunit‐related protein‐reactive CD8+ T cells were detected at type 1 diabetes onset, and the frequency was higher than that in 15 non‐diabetic controls (6.75% vs 0.49 ± 0.78%, mean ± SD). The present type 1 diabetes patient, presented with idiopathic CD4 lymphocytopenia and showed an elevated number of CD8+ T cells, including the islet antigen‐specific CD8+ T cells that might contribute to autoimmune destruction of pancreatic β‐cells.

Keywords

• Idiopathic CD4 lymphocytopenia
• T cells
• Type 1 diabetes