A-23-year-old woman with systemic lupus erythematosus (SLE) and on hemodialysis for 5 years was admitted to the hospital because of severe general fatigue. On admission, laboratory findings showed that fasting plasma glucose levels ranged from 25 â 45 mg/dl, a test for antinuclear antibody (ANA) was positive (1 : 320, with a discrete-speckled pattern), serum C3 and C4 complement and CH50 level were remarkably depressed (22.5 mg/dl, < 5.1 mg/dl, < 13 U/ml, respectively), and insulin receptor antibodies were present (89.3% inhibition of 125I-insulin binding to cultured human lymphocytes by a binding inhibition assay). She also showed acanthosis nigricans. The patient was diagnosed to suffer from a Type B insulin resistance syndrome. The patient's serum insulin and C-peptide levels were markedly elevated during hypoglycemia without insulinoma (2,313.8 microU/ml, 55 ng/ml, respectively). Interestingly, not only postprandial hyperglycemia but also fasting hypoglycemia was observed. Treatment with steroid pulse and subsequent high dose of prednisolone resulted in restoration of euglycemia associated with disappearance of insulin receptor antibodies and improvement of both serum hypocomplementemia and the high titer of ANA. Later, the patient's course was complicated by hemorrhagic shock due to duodenal ulcer and she died of subsequent pneumocystis carinii pneumonia. The presented patient developed a Type B insulin resistance syndrome induced by increased activity of SLE after she had been treated with hemodialysis for 5 years. This is the first reported case with such a history and constellation. It is recommended that SLE patients on dialysis are carefully followed-up by clinical and serological monitoring. Type B insulin resistance syndrome must be considered in the differential diagnosis of hypoglycemia in SLE patients on dialysis.