No abstract

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, 6.3 x 10(6) 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, 10(3)-10(4) in cases of co-infection). Acute rejection was diagnosed in 12 cases, three of which were HRV positive (viral load, 10(3) in two cases of co-infection and 10(5) 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 >10(5) possibly being associated with clinical symptoms, although lower loads can be detected in both symptomatic and asymptomatic patients.

Human Rhinoviruses (HRV) are the most common viral agents, being responsible for upper as well as lower respiratory tract infections. Evidence demonstrating that HRV disease is not exclusively limited to the upper airways and may cause lower respiratory complications, together with the frequency of HRV infections and the increasing number of immunocompromised patients underline the need for including HRV in virological diagnostics of acute lower respiratory tract illness. This article describes the development and optimization of a reverse transcription (RT) real-time PCR assay for quantification of HRV RNA in clinical samples. Efficiency, sensitivity, specificity, inter- and intra-assay variability, and dynamic range have been determined. Subsequently, the assay has been validated on bronchoalveolar lavage (BAL) specimens obtained from immunocompetent and immunocompromised patients.

In contrast to the findings in terms of purity and quantity, the amplifiable RNA was more abundant using RNAzol modified protocol compared to not modified protocol.

Human parainfluenza viruses (HPIVs) are distributed worldwide and are involved mainly in the pathogenesis of respiratory tract infections. The development and optimization of three quantitative reverse transcription real time polymerase chain reactions (RT Real Time Qt-PCRs) and an indirect immunofluorescence (IFA) for the detection and quantitation of HPIV-1, -2 and -3 in clinical samples are described. Efficiency, sensitivity, specificity, inter- and intra-assay variability and turnaround time of the two methods were compared. These assays have been validated on 131 bronchoalveolar lavage specimens. Based on the results obtained, the molecular methods represent a valid and rapid tool for clinical management and should be included in diagnostic panels aimed to evaluate suspected respiratory tract infections.