Detection of human rhinoviruses in the lower respiratory tract of lung transplant recipients

The occurrence of human rhinoviruses (HRV) and its relationship to clinical and histopathological findings were investigated in 127 bronchoalveolar lavage specimens from 36 lung transplant recipients by real-time RT-PCR. In addition, 286 samples from 235 other immunocompromised and immunocompetent patients were also studied. HRV was detected in 41.7% of lung transplant recipients vs 14.5% of other patients (p < 0.0001), and no differences in viral load were observed. Acute respiratory insufficiency was found in 15 cases, three of which were HRV positive (viral load, 6.3x10⁶ RNA copies/ml in one patient with chronic graft dysfunction). A diagnosis of pneumonia was made in 10 out of 127 cases, two of which were HRV positive (viral load, 10³-10⁴ in cases of co-infection). Acute rejection was diagnosed in 12 cases, three of which were HRV positive (viral load, 10³ in two cases of co-infection and 10⁵ in a single infection). HRV infection may involve the lower respiratory tract, particularly in the presence of an impaired pulmonary background, such as a transplanted lung. Clinical evaluation should take into account the viral load, with a load of >10⁵ possibly being associated with clinical symptoms, although lower loads can be detected in both symptomatic and asymptomatic patients.