Renal tubular acidosis type IV as a complication of lupus nephritis.
Renal tubular acidosis (RTA) is a rare complication of renal involvement of systemic lupus erythematosus (SLE). We describe a 24-year-old male with type IV lupus nephropathy as a presenting manifestation of SLE. He presented with improvement of renal function following induction therapy with three pulses of methylprednisolone and 500 mg biweekly pulses of cyclophosphamide. However, a week after the first pulse of cyclophosphamide, the patient presented with a significant increase in legs edema and severe hyperkalemia. Type IV RTA associated with hyporeninemic hypoaldosteronism was suspected in the presence of metabolic acidosis with a normal anion gap, severe hyperkalemia without worsening renal function, and urinary pH of 5. RTA was confirmed with a transtubular potassium concentration gradient of 2 and low levels of plasma aldosterone, renin, angiotensin II, and cortisol. Intravenous bicarbonate, high-dose furosemide, and fludrocortisone were administered with normalization of potassium levels and renal function.
Department of Autoimmune Diseases, Hospital Clínic, Barcelona, Catalonia, Spain.
C
C
Sánchez-Marcos
Department of Nephrology and Renal Transplantation, Hospital Clínic, Barcelona, Catalonia, Spain.
V
V
Hoffman
Department of Autoimmune Diseases, Hospital Clínic, Barcelona, Catalonia, Spain.
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S
Prieto-González
Department of Autoimmune Diseases, Hospital Clínic, Barcelona, Catalonia, Spain.
J
J
Hernández-Rodríguez
Department of Autoimmune Diseases, Hospital Clínic, Barcelona, Catalonia, Spain gespino@clinic.ub.es.
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G
Espinosa
D000138:Acidosis / Q000209:etiology; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D001639:Bicarbonates / Q000008:administration & dosage; D004359:Drug Therapy, Combination; D004487:Edema / Q000209:etiology; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D006947:Hyperkalemia / Q000209:etiology; D006994:Hypoaldosteronism / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D007166:Immunosuppressive Agents / Q000008:administration & dosage; D008180:Lupus Erythematosus, Systemic / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D008181:Lupus Nephritis / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D008297:Male; D020551:Pulse Therapy, Drug; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000008:administration & dosage; D016896:Treatment Outcome; D055815:Young Adult
D000893:Anti-Inflammatory Agents; D001639:Bicarbonates; D005938:Glucocorticoids; D007166:Immunosuppressive Agents; D049994:Sodium Potassium Chloride Symporter Inhibitors
Lupus nephritis; hyperkalemia; renal tubular acidosis