Endocrine Abstracts

Children and adolescents with Type 1 Diabetes Mellitus (T1DM) are at increased risk for developing other autoimmune diseases. We are presenting this rare association of tubulo-interstitial nephritis and uveitis (TINU) with severe hypercalcaemia and type 1 DM. 12 years old girl, with Type 1 Diabetes for 5 years presented with 4 months history of weight loss, abdominal pain, nausea, tiredness, anorexia and recurrent hypoglycaemias. Her HbA1c levels was 38 mmol/mol (5.6%). She was also noted to have normocytic anaemia and proteinuria. Further investigations showed a normal Synacthen test however urea and creatinine were elevated with significant hypercalcaemia. Subsequently, she also developed bilateral granulomatous uveitis with topical steroids. There were no chest symptoms or skin lesions. In view of hypercalcaemia, abnormal kidney functions and granulomatous uveitis she was investigated for Sarcoidosis. She had raised serum Angiotensin Converting Enzyme (ACE) levels. She had normal chest X-ray and ultrasound abdomen. Renal biopsy revealed acute tubule-interstitial nephritis with no evidence of granulomas and giant cells. Her calcium levels continued to be high despite hyperhydation regime, low calcium diet and diuretics, hence received a dose of IV Pamidronate. She was treated with oral prednisolone for 3 months and her renal function and hypercalcaemia recovered completely with no flare-ups in last 18 months. Even though our patient was diagnosed to have TINU, we could not explain raised ACE levels and significant hypercalcaemia. Our patient also had markedly raised 1,25 di-hydroxy vitamin D levels suggesting increased macrophage activation of 1-alpha hydroxylase enzyme causing conversion of 25-OH vitamin D to active hormone. So we suggest patient also had Sarcoidosis in spite of absence of granulomas in renal biopsy.