Rheumatologic Manifestations of Patients With Type B Insulin Resistance

The objectives of this study were to identify laboratory and clinical features associated with type B insulin resistance (TBIR), a rare condition caused by autoantibodies that inhibit the insulin receptor, most frequently occurring in the setting of systemic lupus erythematosus (SLE), and to increase awareness of this rare, life-threatening condition.

Thirty-eight patients with TBIR who were seen at the National Institutes of Health between 1976 and 2024 were included. Retrospective chart review was performed to assign primary rheumatologic diagnoses, characterize endocrinologic laboratory measurements, and identify clinical and laboratory manifestations of SLE, including hypocomplementemia, cytopenias, and autoantibody seropositivity.

SLE was the most frequent underlying diagnosis (81.5%); one patient each had Sjögren disease and primary biliary cholangitis. Patients were predominantly female (89.5%) and Black/African American (84.2%). The median Systemic Lupus Erythematosus Disease Activity Index 2000 score was 14 (interquartile range 7). High or very high U1 RNP autoantibodies were seen in >50% of patients. TBIR was associated with a high prevalence of acute neuropathies of the seventh and/or eighth cranial nerve (18.4%), angioedema (10.5%), and uveitis (5%).

TBIR can be a rare complication of SLE, is associated with the presence of high-titer U1 RNP autoantibodies, and may co-occur with other rare SLE manifestations.