Pure red-cell aplasia: association with systemic lupus erythematosus and primary autoimmune hypothyroidism.

85 Pure red-cell aplasia: association with systemic lupus erythematosus and primary autoimmune hypothyroidism Pure red-cell aplasia has been reported in association with several autoimmune disorders, but not with primary autoimmune hypo-thyroidism. This report confirms another link between pure red-cell aplasia and altered autoimmunity. A 58-year-old woman presented in 1975 with depression and general malaise. Examination showed mild synovitis of the interphalangeal joints of both hands and "butterfly" facial rash. Investigations showed haemoglobin concentration 13 2 g/dl; white cell count 3-4 x 109/l; erythrocyte sedimenta-tion rate 50 mm in first hour; rheumatoid factor 1/40; antinuclear factor 1/64; DNA binding 38 1,, (normal 10-30 °,,); and serum C3 reduced at 62 0% pooled normal serum (normal 70-120%). Lupus erythematosus cells were not seen, urine analysis gave negative results, and thyroid function tests were normal. Chest and joint radiology showed no abnormality. Systemic lupus erythematosus was diagnosed and her disease remained quiescent for the next six years. She then returned with a three-month history of progressive dyspnoea and appreciable lethargy. On examination she was grossly hypothyroid, severely anaemic, and in mild congestive cardiac failure. Investigations showed haemoglobin concentration 6 2 g/dl; mean corpuscular volume 108 6 fl (108 6 pm3), other variables normal; white cell count 5 8 x 109/1; platelet count 432 x 109/l; reticulocytes less than 0 1 o; direct agglutination test negative; and erythrocyte sedimentation rate 145 mm in first hour. Serum iron concentration was 46 lumol/l (276 t4g/100 ml) (normal 13-31 Mtmol/l); total iron binding capacity was normal. Serum vitamin B12 and folate concentrations were normal; and parietal-cell and intrinsic factor antibodies negative. Faecal occult blood tests gave negative results. Other tests showed free thyroxine index one, thyroid-stimulating hormone 60 mU/l (normal 1-10); thyroglobulin antibody 1/2560; thyroid microsomal antibody 1/100; systemic lupus activity quiescent; rheumatoid factor and antinuclear factor titres unchanged; and serum complement concentrations and DNA binding normal. Despite repeated blood transfusions her haemoglobin concentration dropped to 4 7 g/dl with reticulocytopenia. Bone-marrow aspiration showed the characteristic features of pure red-cell aplasia. Treatment was started with prednisolone 30 mg daily and oxymetholone 3 mg/kg/day. Thyroid supplements were also given. The figure shows the response to treatment. Repeated marrow histology two months later showed an active normoblastic reaction, and despite a suboptimal haemoglobin response her symptomatic recovery was almost complete.