Relation between polymerase chain reaction findings and morphological changes during cytomegalovirus infection in transplanted lung

Usual interstitial pneumonia associated with cytomegalovirus infection after percutaneous transluminal coronary angioplasty

An unusual case of cytomegalovirus (CMV) pneumonia in a diabetic patient is presented. The diagnosis was based on typical histopathological findings including intranuclear inclusion bodies combined with molecular identification of CMV in tissue specimens. The possibility of CMV reactivation associated with a previous cardiac procedure, which led to the development of usual interstitial pneumonia, is discussed. Clinicians should be aware of CMV-associated severe bilateral pneumonia developing after cardiac procedures even in non-transplant patients. The correct diagnosis depends on clinical awareness in the appropriate setting along with proof of viral infection.

Quantification of cytomegalovirus DNA in BAL fluid: a longitudinal study in lung transplant recipients

STUDY OBJECTIVES

Cytomegalovirus (CMV) infection is common in patients receiving solid organ transplants, and it is associated with increased morbidity as well as risk for development of chronic rejection. A rapid and sensitive diagnostic method would improve the therapeutic management of CMV infection, including the monitoring of treatment effects. We investigated whether longitudinal determinations of CMV DNA quantities in BAL fluid could be useful for this purpose.

DESIGN

CMV DNA levels in 340 BAL samples from 35 consecutive lung transplant recipients were studied during a median of 18 months. Seventeen (49%) of the patients developed CMV disease with pneumonitis. Twenty-seven CMV disease episodes were diagnosed.

RESULTS

Patients with CMV disease had a significantly higher mean level of CMV copies per milliliter BAL fluid (1,120 +/- 4,379) compared with those without (180 +/- 1,177, p < 0.01). Viral load as well as acute rejection requiring treatment (>/= A2) were independent risk factors associated with CMV disease. Differences between the groups concerning HLA-DR matching, basic immunosuppressive therapy, and CMV serologic status D/R -/+ vs D/R +/+ were not significant. A diagnostic definition of normality based on the mean level of all episodes without CMV disease +2 SD would discriminate only 9 of the 27 CMV episodes.

CONCLUSIONS

Although the viral load is increased during episodes of clinical CMV disease in lung transplant recipients, the quantitative PCR assessment of CMV DNA in BAL fluid is not discriminative enough to be useful as a diagnostic tool for CMV disease.

The origin of alveolar macrophages in the transplanted lung: a longitudinal microsatellite-based study of donor and recipient DNA

Transplanted lungs are initially populated by donor pulmonary alveolar macrophages (PAMs). These will form major antigen presenters for the recipient's suppressed immune system. They may be expected to be replaced by recipient major histocompatibility complex-compatible cells, with time. We have isolated CD14+ PAMs from bronchoalveolar lavage specimens for 6 months after transplantation and identified their origin by using microsatellite analysis. This DNA-based technology permits the reliable identification of the origin of cells from different individuals. We show that replacement of donor PAMs occurs with individual dynamics in each case. Recipient PAMs usually appeared within 2 weeks, whereas donor cells could be retained for as long as 6 months. In this limited series, there was no obvious correlation between the dynamics of this process and the occurrence of rejection episodes or infections.

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.