Legionella pneumonia complicated with severe acute kidney injury requiring continuous renal replacement therapy: a case series.

BACKGROUND

Legionella pneumophila is a bacterium found in natural water sources and artificial water systems. The most widely reported manifestation of Legionella infection is pneumonia, which is also known as Legionnaires' disease. Legionnaires' disease is typically spread through inhalation of aerosolized water droplets containing Legionella bacteria. This usually manifests with cough, fever, shortness of breath, and gastrointestinal disturbances. Legionella infection is known to cause a variety of extrapulmonary complications, including acute kidney injury, rhabdomyolysis, cardiac complications, liver involvement, and electrolyte imbalances. Acute kidney injury in Legionella disease is due to the cytotoxic effects of bacteria that directly invade renal tubular epithelial cells, the immune response triggered by bacteria that leads to systemic inflammation, thereby compromising renal perfusion and microthelial dysfunction, which reduces the blood flow of kidneys, causing hypoperfusion. Indirect causes for acute kidney injury include dehydration and nephrotoxic medication. Acute kidney injury in patients with Legionella pneumonia is oliguric but reversible with antibiotic treatment. Diagnosis of Legionella disease is through a combination of clinical assessment, laboratory tests, and imaging. Legionella urinary antigen testing and polymerase chain reaction confirms the diagnosis. Treatment of choice is antibiotics along with symptomatic management.

CASE PRESENTATION

We report three cases of Legionnaires' disease from a tertiary care hospital in Australia that were complicated with severe acute kidney injury requiring continuous renal replacement therapy. All three patients were middle aged immunocompetent males; two were Australian and one was Macedonian. Case 1 was associated with acute kidney injury, hyponatremia, rhabdomyolysis, delirium, and liver impairment. The patient in case 2 developed acute kidney injury, rapid atrial fibrillation, type 2 non-ST elevation myocardial infarction, and liver function derangement. Case 3 was associated with acute kidney injury, rhabdomyolysis, and subdural hemorrhage secondary to fall. All our patients were treated with intravenous antibiotics, supplemental oxygen therapy, and continuous renal replacement therapy, after which they achieved complete recovery.

CONCLUSION

Legionella infection can lead to serious extrapulmonary complications, including acute kidney injury, rhabdomyolysis, cardiac, and liver involvement. Timely diagnosis and prompt management are important in addressing both the infection and its extrapulmonary complications.