Pulmonary -renal syndrome (PRS) is a rare but critical condition involving simultaneous inflammation of pulmonary capillaries and glomeruli, leading to diffuse alveolar hemorrhage (DAH) and rapidly progressive glomerulonephritis (RPGN). While PRS is primarily associated with autoimmune diseases such as Goodpasture syndrome and ANCA -associated vasculitis, infectious causes like Legionella pneumophila are rare but significant. We present a unique case of PRS caused by Legionella pneumophila in a ۱۶ -year-old male, underscoring the diagnostic and therapeutic challenges associated with this unusual manifestation. A ۱۶ -year-old male presented with dyspnea, hemoptysis, cough, and hematuria. Over ۱۰ days, his urine output decreased, and laboratory tests revealed thrombocytopenia, elevated creatinine (۸.۵۸ mg/dL), and BUN (۹۸ mg/dL), indicative of renal failure. Despite significant respiratory and renal dysfunction, autoimmune markers (ANA, ANCA, and anti -dsDNA) were negative. The patient underwent plasmapheresis, intravenous immunoglobulin (IVIG), and corticosteroids, which stabilized his platelet count but did not reverse renal dysfunction. Renal biopsy revealed hypertensive nephrosclerosis and tubulointerstitial nephritis, which were atypical given his age and lack of prior hypertension history.
Legionella infection was suspected due to persistent respiratory symptoms unresponsive to initial therapy. Based on clinical judgment, erythromycin was initiated, leading to substantial respiratory improvement. However, his renal impairment progressed, requiring chronic hemodialysis and eventual kidney transplantation. This case emphasizes the necessity of evaluating Legionella as a potential etiology of PRS, particularly in young individuals with unusual manifestations. In the absence of conclusive diagnostic testing, clinical judgment and prompt antibiotic intervention can stabilize patients; however, renal problems might require long -term treatments such as transplantation.