Parenchymal trafficking of pleural mesothelial cells in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterised by myofibroblast proliferation leading to architectural destruction. Neither the origin nor the continued proliferation of myofibroblasts is well understood. Explanted human IPF lungs were stained by immunohistochemistry for calretinin, a marker of pleural mesothelial cells (PMCs). Chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF) lungs acted as controls. The number of PMCs per 100 nucleated cells and per photomicrograph was estimated along with the Ashcroft score of fibrosis. Mouse PMCs expressing green fluorescent protein (GFP) or labelled with nanoparticles were injected into the pleural space of mice given intranasal transforming growth factor (TGF)-ß1. Mouse lungs were lavaged and examined for the presence of GFP, smooth muscle α-actin (α-SMA) and calretinin. Calretinin-positive PMCs were found throughout IPF lungs, but not in COPD or CF lungs. The number of PMCs correlated with the Ashcroft score. In mice, nanoparticle-laden PMCs were recoverable by bronchoalveolar lavage, depending on the TGF-ß1 dose. Fluorescent staining showed α-SMA expression in GFP-expressing PMCs, with co-localisation of GFP and α-SMA. PMCs can traffic through the lung and show myofibroblast phenotypic markers. PMCs are present in IPF lungs, and their number correlates with IPF severity. Since IPF presumably begins subpleurally, PMCs could play a pathogenetic role via mesothelial-mesenchymal transition.

Quantification of cytotoxic T-cell gene transcripts in human lung transplantation.

BACKGROUND: Differentiating between acute rejection and cytomegalovirus (CMV) infection is one of the major challenges of lung transplantation. The aims of this study were to: (1) quantify the transcription of the cytotoxic T lymphocyte (CTL) effector molecules in the bronchoalveolar lavage (BAL) of lung transplant recipients and (2) evaluate the clinical usefulness of this technique. METHODS: Sixty-six single-lung, double-lung, or heart-lung transplant patients were prospectively enrolled in the study. BAL was performed either for routine surveillance or for acute graft dysfunction. RNA was extracted from BAL cell pellets and underwent competitive reverse transcription-assisted polymerase chain reaction (RT-PCR) for perforin, granzyme B, granulysin, and Fas ligand. Gene transcript analysis was compared to clinical diagnosis established by conventional methods [BAL microbiological and transbronchial biopsy (TBB) analyses]. RESULTS: After exclusion of several BAL according to the study criteria, 62 BAL were submitted for data analysis. Significantly higher expression of all the analyzed transcripts was found during CMV infection, compared with each of the other defined diagnostic categories, namely nonsignificant pathology, acute rejection, and nonviral pulmonary infection. CONCLUSION: Quantification by competitive RT-PCR of the CTL effector molecule transcripts (perforin, granzyme B, granulysin, and Fas ligand) could represent a valuable tool for the differential diagnosis of graft dysfunction in lung transplantation.

Influenza pneumonia in a paediatric lung transplant recipient.

Although a common cause of morbidity and mortality in the general population, influenza infections are uncommon in lung transplant recipients and, to date, have only been associated with transient declines in pulmonary function and a relatively benign clinical course. This paper describes severe influenza pneumonia in a 13-year-old paediatric lung transplant recipient (5 months after double lung transplantation). Influenza pneumonia was diagnosed by direct fluorescent antibody testing and viral culture of bronchoalveolar lavage fluid. The patient required mechanical ventilation for 2 days due to respiratory failure and fatigue. Since his recovery from this pneumonia, he has developed obliterative bronchiolitis and currently awaits re-transplantation.

The surgical management of severe gastroparesis in heart/lung transplant recipients.

This article describes the use of gastric bypass surgery for severe gastroparesis in two lung transplant recipients. In addition to feeding intolerance, both our patients suffered from severe erosive esophagitis, transfusion-dependent upper GI hemorrhage, and recurrent aspiration pneumonia. They responded poorly to promotility agents and were eventually treated with Roux-en-Y esophagojejunostomy-one patient with subtotal gastrectomy, and one with gastric bypass without distal gastric resection. Both cases were improved by surgery. Early surgical referral may be indicated in the management of lung transplant recipients with severe symptomatic gastroparesis in whom medical management has failed. On the basis of our experience, gastric bypass with esophagojejunostomy is a worthwhile option in lung transplant recipients with severe gastroparesis.

Recurrent Pneumocystis carinii colonization in a heart-lung transplant recipient on long-term trimethoprim-sulfamethoxazole prophylaxis.

INTRODUCTION: In the setting of organ transplantation, prior to prophylaxis, Pneumocystis carinii pneumonia (PCP) had been a common clinical problem, particularly in heart-lung and lung recipients who receive long-term immunosuppressive therapy to prevent allograft rejection. Continuous oral trimethoprim-sulfamethoxazole (TMP-SMX) has been highly effective in preventing PCP in these patients. REPORT: In this paper we report a case of recurrent Pneumocystis carinii infection in a chronic (> 15 years) heart-lung allograft recipient on long-term TMP-SMX prophylaxis. Twice, in 1995 and again in 1998, Pneumocystis carinii infection was diagnosed by bronchoalveolar lavage (BAL), in the same patient, despite continued oral TMP-SMX (960 mg TMP/4800 mg SMX per week) prophylaxis. The subject was not lymphopenic (his CD4 count was 569/mm3) and there was no associated deterioration in pulmonary function, nor evidence of hypoxemia. CONCLUSION: This case demonstrates that asymptomatic Pneumocystis carinii lung infections may recur in chronic heart-lung transplant recipients who take standard oral PCP prophylaxis.