RENAL TUBULAR DYSFUNCTION AND HYPERGAMMAGLOBULINEMIA

. A report is given on a female patient, 32 years of age, with a history of slight joint distress, recurrent dependent oedema, hypokalaemia, hypergammaglobulinaemia and positive tests for rheumatoid factor. Electrolyte balance studies revealed latent renal tubular acidosis (RTA), impaired renal pH-regulation and impaired renal conservation of sodium and potassium. Systemic pH was found to be largely dependent on the dietary load of sodium chloride. Correction of the hypokalaemia resulted in frank systemic acidosis, whereas persistent hypokalaemia was associated with alkalosis. The situation thus differed from that found in primary RTA. Electron microscopic and light microscopic studies from a renal biopsy revealed simultaneous signs of tubular and interstitial nephritis and slight glomerular reaction. Immunoglobulin deposits were seen in the tubuli and the glomerular basement membrane by the immunofluorescence method.