Distal renal tubular acidosis has been reported in several diseases associated with hypergammaglobulinemia, particularly Sjögren's syndrome. Since HIV infection is now a common cause of hypergammaglobulinemia, we evaluated renal acidification under basal and dynamic conditions in 8 asymptomatic HIV-seropositive subjects. Basal acid-base status was normal in all except 1 patient who had respiratory acidosis subsequent to recent pneumonia. Acid-loading tests showed normal acid excretion except for 1 patient who had low acid excretion attributed to non-ingestion of the ammonium chloride capsules. Bicarbonate-loading tests showed normal distal acidification indexes in 7 patients. The only patient with a low acidification defect was diagnosed 2 weeks later as having tuberculosis. Our results suggest that hypergammaglobulinemia per se is not a sufficient condition to induce renal tubular acidosis.