1246 IDDM AND CONGENITAL HYPOGAMMAGLCBULIHEMIA (CHGG)

Abstract

Viral and immunologic factors are believed to contribute to the development of IDDM. It is not clear if subclinical pancreatitis without islet-cell antibodies (ICA) will manifest IDDM. A 19 year old white male receiving γglobulin since infancy for CHGG developed IDDM (EG, 690 mg/dl; serum insulin <3.0 uu/ml; HbAl, 15.6%). Clinical course included recurrent infections since infancy, recurrent diarrhea and chronic lung disease. He had normal sweat Na. Fecal fat, 8.9 gm/24h (HL: <7.0). Low urinary PABA (48%), after bentiromide ingestion and improvement of diarrhea with pancreatic enzyme therapy were suggestive of pancreatic exocrine deficiency. Serum IgG, 159 mg%; IgM, 12 mg%; undetectable IgA and IgE; poor antibody responses to influenza and pneumococcal vaccine; absent B cells, but normal lymphocytes, 1095 (15%); T cells, 887 (81%), and suppressor cells, 504 (46%); deficient helper cells, 285 (26%) with reversed H:S ratio, 0.56. Hormal lymphocyte PHA stimulation and negative delayed hypersensitivity skin tests. Antibody titers were low to CMV and EBV and absent to Coxsackie B 1 to B 6. ICA and immune responses to insulin were negative. His non-diabetic brother with common variable HGG had similar immune status except for 3% B cells; normal suppressor cells, 256 (27%); helper cells, SUS (42%) and H:S ratio,, 1.36. Defective immune regulation in this patient may have fascilitated the development of subclinical pancreatitis with resulting exocrine deficiency and IDDM without ICA. To our knowledge this is the first report of association of IDDM and CHGG.