Utility of Mean Platelet Volume to Diagnose Pneumonia in Patients With Solid-Organ Transplant

Despite improved success with solid-organ transplant procedures, recipients remain at risk for infections, including pneumonia, due to their immunosuppressive regimens. In solid-organ transplant patients, clinical findings of pneumonia can be nonspecific, and diagnosis of pneumonia may be difficult as several conditions (drug lung, hypervolemia, infections, hemorrhage) can led to pulmonary infiltrates, mimicking pneumonia in these patients. The role of mean platelet volume, a predictor of inflammatory disease, with elevated values inversely correlated with inflammatory problems, in the diagnosis of pneumonia has not yet been investigated in solid-organ transplant patients. Here, we retrospectively investigated mean platelet volume in diagnosis of pneumonia in transplant patients.

Medical records of solid-organ transplant patients from 2011 to 2016 were reviewed for demographic, clinical, radiographic, laboratory, and microbiology data. Transplant type, immunosuppressive drugs, and clinical outcomes were noted. Pneumonia diagnosis was based on clinical respiratory symptoms and signs, imaging findings, positive microbiological tests, pathologic findings, laboratory findings, or effective clinical treatment trials.

Our study included 70 patients (47 male/23 female; mean age of 46 ± 14 years), comprising 26 liver and 44 renal transplant recipients. Pneumonia was diagnosed radiologically in 30 patients (42.9%), with procalcitonin positive in 11 patients (36.7%), C-reactive protein elevated in 29 patients (96.7%), and leukocytes increased in 6 patients (20%). When laboratory measurements were compared with mean platelet volume, mean platelet volume values were significantly lower in patients with pneumonia who had elevated procalcitonin levels (P = .038).

We found that mean platelet volume for diagnosis of pneumonia in solid-organ transplant patients was not a promising tool. Considering the difficulties in caring for transplant patients with pulmonary infiltrates, clinical decisions should be based on clinical, laboratory, microbiological, and radiologic findings.