HIV Infection Itself may be a Cause of Hypokalemic Distal Renal Tubular Acidosis without Hypergammaglobulinemia

Distal renal tubular acidosis (dRTA) is seen in the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) population in the setting of hypergammaglobulinemia and antiretroviral agents, whereas isolated HIV infection is rarely reported to be associated with dRTA. We report a case of a young woman with a history of untreated HIV/AIDS who presented with profound generalized weakness and refractory hypokalemia along with non-anion gap metabolic acidosis and inappropriately high urine pH. Her serum gamma-globulin level was not significantly elevated and she was not on highly active antiretroviral therapy (HAART). No other cause of dRTA was evident. Subsequently, a diagnosis of dRTA secondary to isolated HIV/AIDS was made. Distal RTA can be acquired or inherited and is caused by defects in proton pumps or pH pressure gradients. In dRTA, the potassium level can be low, normal, or even high depending upon the pathophysiologic abnormality. Early recognition and prompt treatment is imperative to avoid the serious consequences of severe electrolyte and metabolic disturbances. Our case report is a reminder to clinicians to be mindful of this rare condition when evaluating unexplained dRTA and to include HIV/AIDS as part of the differential diagnosis of dRTA even in the absence of significant hypergammaglobulinemic (IgG level was slightly elevated) state or antiretroviral agents. We believe this is the second such case to be documented.