Increased T cell proliferative responses to islet antigens identify clinical responders to anti-CD20 monoclonal antibody (rituximab) therapy in type 1 diabetes

KC Herold, MD Pescovitz, P McGee… - The Journal of …, 2011 - journals.aai.org
KC Herold, MD Pescovitz, P McGee, H Krause-Steinrauf, LM Spain, K Bourcier, A Asare…
The Journal of Immunology, 2011journals.aai.org
Type 1 diabetes mellitus is believed to be due to the autoimmune destruction of β-cells by T
lymphocytes, but a single course of rituximab, a monoclonal anti-CD20 B lymphocyte Ab,
can attenuate C-peptide loss over the first year of disease. The effects of B cell depletion on
disease-associated T cell responses have not been studied. We compare changes in
lymphocyte subsets, T cell proliferative responses to disease-associated target Ags, and C-
peptide levels of participants who did (responders) or did not (nonresponders) show signs of …
Abstract
Type 1 diabetes mellitus is believed to be due to the autoimmune destruction of β-cells by T lymphocytes, but a single course of rituximab, a monoclonal anti-CD20 B lymphocyte Ab, can attenuate C-peptide loss over the first year of disease. The effects of B cell depletion on disease-associated T cell responses have not been studied. We compare changes in lymphocyte subsets, T cell proliferative responses to disease-associated target Ags, and C-peptide levels of participants who did (responders) or did not (nonresponders) show signs of β-cell preservation 1 y after rituximab therapy in a placebo-controlled TrialNet trial. Rituximab decreased B lymphocyte levels after four weekly doses of mAb. T cell proliferative responses to diabetes-associated Ags were present at baseline in 75% of anti-CD20–and 82% of placebo-treated subjects and were not different over time. However, in rituximab-treated subjects with significant C-peptide preservation at 6 mo (58%), the proliferative responses to diabetes-associated total (p= 0.032), islet-specific (p= 0.048), and neuronal autoantigens (p= 0.005) increased over the 12-mo observation period. This relationship was not seen in placebo-treated patients. We conclude that in patients with type 1 diabetes mellitus, anti-B cell mAb causes increased proliferative responses to diabetes Ags and attenuated β-cell loss. The way in which these responses affect the disease course remains unknown.
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