Legionella: an infectious cause of rhabdomyolysis-associated acute renal failure
Files
Publication Date
2025
Abstract
Introduction: Legionella species are gram negative bacteria that cause pneumonia both sporadically and in outbreaks. Infection with Legionella can result in multisystem illness with extrapulmonary manifestations including abdominal pain, diarrhea, headache, encephalopathy, hyponatremia, and liver injury. Renal injury from legionellosis is less common. Here, we present a case of legionella-associated rhabdomyolysis resulting in acute renal failure secondary to heme pigment nephropathy despite unimpressive muscle enzyme levels. Case Presentation: A 56-year-old previously healthy male presented with one week of fatigue, fever, generalized abdominal pain, and shortness of breath. Initial vital signs were significant for temperature of 39.0 °C, heart rate of 115, blood pressure of 123/74, respiratory rate of 28/min, and SpO2 90% on room air. His creatinine was 14.8, blood urea nitrogen (BUN) 105, bicarbonate 15 with anion gap of 22, sodium of 126, and creatine kinase (CK) 6528. There was mild elevation of his liver function studies. Chest X-ray revealed a left lower lobe infiltrate. This was overall consistent with sepsis secondary to lobar pneumonia and associated hypoxemic respiratory failure, acute oliguric renal failure with uremic metabolic acidosis, hyponatremia, and transaminitis. He was started on ceftriaxone and azithromycin for community acquired pneumonia as well as IV fluids. Legionella pneumophila urine antigen returned positive on hospital day 2, confirming the diagnosis of Legionellosis. A broad workup was performed for the cause of renal failure. This included strongly positive urine myoglobin and renal biopsy with findings of heme pigment-induced acute tubular injury. The patient was treated with two days of hemodialysis on hospital days 4 and 5 to correct acidosis and uremia. Renal function and urine output improved without need for further dialysis. His creatinine was 2.17 and BUN 38 on discharge. The lobar pneumonia and hypoxemia resolved with an extended course of azithromycin transitioned to levofloxacin. The source of legionella was never identified by the local health department. Discussion: This case highlights acute renal failure secondary to rhabdomyolysis, a rare complication in patients with Legionella pneumonia. Although acute kidney injury in rhabdomyolysis is typically associated with admission CK levels >15000, it can occur with CK levels as low as 5000 in the presence of additional insults such as sepsis, dehydration, or acidosis. This was the case in this patient, who had a presenting CK level of 6528. The mechanism of rhabdomyolysis in Legionellosis is poorly understood but is thought to be related to either direct muscle infection or indirect muscle injury related to bacterial toxin, with contributing factors of fever, rigors, and hypovolemia. Prior descriptions of legionella-associated rhabdomyolysis and renal failure are limited to case reports and literature reviews
Specialty/Research Institute
Graduate Medical Education
