Soft-tissue calcification in systemic lupus erythematosus

Abstract

Soft-tissue calcification, a well known roentogen manifestation of connective tissue disease, is commonly associated with PSS and DM-PM. However the occurrence of soft-tissue calcification in SLE has been rarely emphasized. We observed an SLE patient with widespread soft-tissue calcification. A 15 years old girl developed SLE in 1974 with recurrent symptoms of arthralgia, Raynaud's phenomenon, fever, hair loss and positive ANA (1: >1280 speckled pattern), hypergammaglobulinemia. She was treated with prednisolone 15 mg every day and responded it. In May 1975, she had a mild proteinuria, granular cast and slight hypocomple-mentemia, but she well responded to 30 mg prednisolone every day. In Feb. 1977, she had a coin sized, hard and painful subcutaneous mass at left buttock. And then, she noticed similar masses at right buttock, right shoulder, bilateral popliteal fossa and thighs. X-ray films of the extremities and the pelvis showed extensive soft-tissue calcifications. In May 1978, she was admitted for painful, enlarged subcutaneous masses at bilateral buttocks. At the admisson, LE cell, ANA and DNA-Ab. were negative, but RNP, SSA-Ab. and unknown ENA-Ab. were detected. Serum enzyme levels (GOT, LDH, CPK, aldolase, amylase), serum calcium concentration, inorganic phosphorus values, ionized calcium concentration, parathyroid function (P.T.H., %TRP) and renal function were all within normal limits from 1974 to 1978. Subcutaneous masses at buttocks were excised. Histological examination revealed a subcutaneous soft-tissue calcification without evidence of fat necrosis, myositis, and vasculitis. Excised material was a compounds of hydroxy appatite and tricalcium phosphate by the infrared spectroscopic analysis. The occurrence of soft-tissue calcification in SLE was rare and only 25 case reports have been described. Analysis of SLE cases revealed that soft-tissue calcification occurred in patients with a long standing illness, sometimes associated with skin ulcer, myositis and fat necrosis. But the pathogenesis of soft-tissue calcification in this case was unclarified. It was a matter of interest to us in this case that 99 “mTe-MDP compounds accumulated at the site of soft-tissue calcification. We suggest that 99mTe-phosphate compounds are capable of detecting soft-tissue calcification and useful for its diagnosis. © 1982, The Japan Society for Clinical Immunology. All rights reserved.