UTILITY OF BRONCHOALVEOLAR LAVAGE IN ASSESSING PNEUMONIA IN IMMUNOSUPPRESSED RENAL-TRANSPLANT RECIPIENTS

PURPOSE: To determine if initial results obtained from diagnostic bron choalveolar lavage (BAL) in immunosuppressed renal transplant patients with pulmonary infiltrates, fever, or hypoxemia can affect therapeuti c decisions, morbidity, and mortality. DESIGN: A retrospective study o f all BAL specimens obtained from renal transplant patients from Janua ry 1985 through June 1991. Initial results of Gram stain, cytology, ce ll differential count, and semi-quantitative bacterial cultures, all a vailable within 24 hours of bronchoscopy, were compared with clinical outcomes and final diagnoses. SETTING: University hospital nephrology- transplant/pulmonary service. PATIENTS. Seventy renal transplant patie nts with a suspected pneumonia were stratified into 3 groups. A total of 48 patients underwent 58 bronchoscopies. Group 1 was comprised of 3 2 BALs that yielded 1 or more infectious organisms and was considered diagnostic. Group 2 (n = 26) were those BALs in which no organism was isolated and were thus nondiagnostic. Twenty-two additional immunosupp ressed renal transplant recipients with pneumonia were considered by t he admitting transplant nephrologist to have an uncomplicated communit y-acquired lung infection and thus were empirically treated and did no t undergo BAL (Group 3).METHODS. BAL fluid analysis included cell diff erential count, cytopathologic examination, and culture for mycobacter ia, legionella, fungi, viruses, and bacteria using a semi-quantitative technique. Etiologic diagnosis and the time of onset of the infectiou s processes were recorded. Therapeutic outcome and mortality were dete rmined for each group. RESULTS: Thirty-nine etiologic organisms were f ound in 32 patients, with 6 patients having more than 1 infection. Twe nty-two patients had 26 negative BALs, and 8 of these patients were cl inically believed to have a volume overload state. Eight of 13 (61%) p atients with bacterial pneumonia had BAL neutrophil counts greater tha n 20%, whereas 11 of 13 (84%) patients without bacterial pneumonia had neutrophil counts less than 20% (p <0.05). Those patients with an inf ectious etiology remained in the hospital longer than patients without a specific etiologic organism identified (p <0.02). Therapeutic decis ions leading to the institution of specific antibiotics were more freq uently made in patients with a diagnostic BAL (p <0.0001). An overall 3-month mortality (16%) was low compared with the historical rate (30% ). CONCLUSION: BAL is a useful procedure in the diagnosis of an infect ious process in immunosuppressed renal transplant patients where initi al results can alter therapy in more than 70% of cases.