Patrizio Vitulo

Regulatory CD4+CD25+ T cells in the peripheral blood of lung transplant recipients: correlation with transplant outcome.

Background. The subset of CD4+CD25+ regulatory T cells, recently identified in humans, may play a central role in the regulation of immune tolerance to graft survival. Methods. This study assesses the frequency and functional profile of CD4+CD25+CD69− cells in the peripheral blood of lung transplant recipients (>3 years from transplantation), 10 of whom were in a stable clinical condition and 11 of whom demonstrated chronic rejection (bronchiolitis obliterans syndrome). We also studied a group of seven healthy subjects. Results. The frequency of CD4+ T cells expressing CD25 (CD4+CD25+) and the highest levels (CD25high) were lower in patients with bronchiolitis obliterans syndrome compared with healthy subjects and subjects in a stable clinical condition (P ≤0.01). Purified CD4+CD25+ cells exhibited a regulatory functional profile in vitro: they were hyporesponsive, suppressed the proliferation of CD4+CD25− cells, and produced interleukin-10. Conclusion. These results provide in vivo evidence that peripheral CD4+CD25+ T cells may represent an important regulatory subset in lung transplantation.

Beta defensin-2 is reduced in central but not in distal airways of smoker COPD patients.

Background Altered pulmonary defenses in chronic obstructive pulmonary disease (COPD) may promote distal airways bacterial colonization. The expression/activation of Toll Like receptors (TLR) and beta 2 defensin (HBD2) release by epithelial cells crucially affect pulmonary defence mechanisms. Methods The epithelial expression of TLR4 and of HBD2 was assessed in surgical specimens from current smokers COPD (s-COPD; n = 17), ex-smokers COPD (ex-s-COPD; n = 8), smokers without COPD (S; n = 12), and from non-smoker non-COPD subjects (C; n = 13). Results In distal airways, s-COPD highly expressed TLR4 and HBD2. In central airways, S and s-COPD showed increased TLR4 expression. Lower HBD2 expression was observed in central airways of s-COPD when compared to S and to ex-s-COPD. s-COPD had a reduced HBD2 gene expression as demonstrated by real-time PCR on micro-dissected bronchial epithelial cells. Furthermore, HBD2 expression positively correlated with FEV1/FVC ratio and inversely correlated with the cigarette smoke exposure. In a bronchial epithelial cell line (16 HBE) IL-1β significantly induced the HBD2 mRNA expression and cigarette smoke extracts significantly counteracted this IL-1 mediated effect reducing both the activation of NFkB pathway and the interaction between NFkB and HBD2 promoter. Conclusions This study provides new insights on the possible mechanisms involved in the alteration of innate immunity mechanisms in COPD.

Human cytomegalovirus pp67 mRNAemia versus pp65 antigenemia for guiding preemptive therapy in heart and lung transplant recipients: A prospective, randomized, controlled, open-label trial

Background. Preemptive therapy of human cytomegalovirus (HCMV) infections has gained popularity in transplantation centers. However, standardized protocols are not available. In particular, whether a qualitative molecular assay for detection of a late (pp67) HCMV mRNA represents a valuable alternative to quantitative antigenemia remains to be defined. Methods. Overall, 82 heart (HTR) and lung (LTR) transplant recipients were randomized into two arms, where therapy was guided by qualitative pp67 mRNA NASBA (40 patients) or quantitative antigenemia (42 patients). In the NASBA arm, both primary and recurrent infections were treated upon first confirmed positive NASBA result. In the antigenemia arm, primary infections were treated upon first confirmed positive result, while recurrent infections were treated upon cutoff of 100 pp65-positive leukocytes. In both arms, therapy was stopped upon virus disappearance. Primary endpoint was duration of therapy. Results. The number of treated/infected patients was significantly higher in the NASBA arm (25/30 vs. 15/39;P =0.015), as was the number of treated/relapsing patients (5/8 vs. 1/11;P =0.040), whereas the number of HCMV-infected/total number of patients was significantly higher in the antigenemia arm (39/42 vs. 30/40;P =0.026). Thus, in the NASBA arm, although the median duration of therapy was shorter compared to antigenemia (17 vs. 21 days, P >0.05), the overall number of days of therapy was significantly higher. No patient developed HCMV disease. Conclusion. pp67 mRNA NASBA can safely replace antigenemia, with some apparent advantages (semiautomation and objectivity of test results) and disadvantages (overtreatment of patients and greater duration of overall treatment).

Efficacy of tacrolimus rescue therapy in refractory acute rejection after lung transplantation

BACKGROUND Encouraging results in transplantation of other solid organs led to investigation of the use of tacrolimus in lung transplantation as a salvage immunosuppressant in persistent acute rejection. METHODS The incidence and severity of acute rejection and the number of steroid pulses were analyzed in 20 lung recipients who were converted from a cyclosporine- to a tacrolimus-based immunosuppressive regimen because of refractory biopsy-proven acute rejection. RESULTS Tacrolimus was started 12.0 +/- 13.0 months after transplantation, and the mean follow-up was 25.0 +/- 13.7 months. After shifting to tacrolimus, a significant decline was observed in both the number of acute rejections per patient (3.0 +/- 1.56 to 0.85 +/- 1.14, p < 0.0001), and the incidence of acute rejection per 100 patient-days (1.52 +/- 0.99 to 0.14 +/- 0.21, p < 0.0001). Furthermore, the average histologic grade of rejection decreased from 1.9 +/- 0.8 to 0.4 +/- 0.5 (p < 0.0001). Methylprednisolone pulses similarly decreased from 1.9 +/- 1.3/patient to 0.3 +/- 0.7/patient (p < 0.0001). During cyclosporine immunosuppression, the mean forced expiratory volume in 1 second decreased to 84.4% +/- 13.3% of individual best value. The average lung function parameters were stable 3 months after the change of medication, and then began to improve. After an average follow-up of 36.5 +/- 19.2 months, 2 patients have developed bronchiolitis obliterans syndrome (one has Stage 1 and one has Stage 3). CONCLUSION Conversion to a tacrolimus-based immunosuppressive regimen for refractory acute lung rejection is associated with reduced incidence and severity of acute rejection episodes, steroid sparing, and stabilization or improvement of pulmonary function.

The role of 1.5T cardiac MRI in the diagnosis, prognosis and management of pulmonary arterial hypertension

Cardiovascular magnetic imaging is a noninvasive, three dimensional tomographic technique that allows for a detailed morphology of the cardiac chambers, the accurate quantification of right ventricle volumes, myocardial mass, and transvalvular flow. It can also determine whether right ventricular diastolic function is impaired through pulmonary hypertension. The aim of this article is to review the main kinetic, morphological and functional changes of the right ventricle that can occur in patients affected by pulmonary arterial hypertension (PAH) and to assess how the MRI findings can influence the prognosis, and guide the decision-making strategy. In those cases in which MRI shows a significant cardiac diastolic dysfunction, the prognosis is predictive of pharmacological treatment failure, and mortality. This leaves double lung-heart transplantation as the only therapeutic option. The coexistence of PAH and left ventricle impairment causes worse right ventricle function, leads to a poor prognosis, and may change the therapeutic strategies (for example, PAH associated with left ventricle dysfunction may require a double lung-heart transplant).

Risk Factors for Chronic Renal Dysfunction in Lung Transplant Recipients

Several factors predispose to renal dysfunction (RD), a common complication of solid organ transplants. We evaluated the impact of clinical and laboratory parameters on the decline of renal function in lung and heart-lung transplant recipients. We enrolled 45 patients who survived more than 6 months after transplantation, had normal renal function and urinalysis before the surgery. The prognostic value of variables for the occurrence of RD was calculated by univariate analysis. Thirty patients developed RD, defined as doubling of serum creatinine or creatinine steadily >1.5 mg/dL after a median time of 12 months. Serum creatinine above 0.9 mg/dL during the month preceding lung transplant, systolic blood pressure above 130 mmHg, and pretransplant idiopathic pulmonary hypertension were significantly associated with the development of RD. Our findings indicate that increased systolic blood pressure, reduced glomerular filtration rate, and idiopathic pulmonary hypertension are risk factors for chronic RD in lung transplant recipients.

Time course of matrix metalloproteases and tissue inhibitors in bleomycin-induced pulmonary fibrosis

To investigate simultaneously localization and relative activity of MMPs during extracellular matrix (ECM) remodeling in bleomycin-induced pulmonary fibrosis in rat, we analyzed the time course of the expression, activity and/or concentration of gelatinases MMP-2 and MMP-9, collagenase MMP-1, matrylisin MMP-7, TIMP-1 and TIMP-2, both in alveolar space (cellular and extracellular compartments) and in lung tissue. MMP and TIMP expression was detected (immunohistochemistry) in lung tissue. MMP activity (zymography) and TIMP concentration (ELISA) were evaluated in lung tissue homogenate (LTH), BAL supernatant (BALs) and BAL cell pellet (BALp) 3, 7, 14, and 28 days after bleomycin intratracheal instillation. Immunohistochemistry showed an extensive MMP and TIMP expression from day 7 in a wide range of structural and inflammatory cells in treated rats. MMP-2 was present mainly in epithelia, MMP-9 in inflammatory cells. MMP-2 and MMP-9 activity was increased respectively in BAL fluid and BAL cells, with a peak at day 7. TIMP-1 and TIMP-2 concentration (ELISA) enhancement was delayed at day 14. In conclusion gelatinases and their inhibitors are significantly activated during bleomycin-induced pulmonary fibrosis. Marked changes in gelatinases activity are observed early in the alveolar compartment, with a prevailing extracellular activity of MMP-2 and a predominant intracellular distribution of MMP-9, while enzyme activity changes in lung parenchyma were less evident. In the repairing phase the reduction of gelatinases activity is synchronous with a peak of alveolar concentration of their inhibitors.

Outcome of Transplantation Using Organs From Donors Infected or Colonized With Carbapenem-Resistant Gram-Negative Bacteria

Donor‐derived infections due to multidrug‐resistant bacteria are a growing problem in solid organ transplantation, and optimal management options are not clear. In a 2‐year period, 30/214 (14%) recipients received an organ from 18/170 (10.5%) deceased donors with infection or colonization caused by a carbapenem‐resistant gram‐negative bacteria that was unknown at the time of transplantation. Among them, 14/30 recipients (47%) received a transplant from a donor with bacteremia or with infection/colonization of the transplanted organ and were considered at high risk of donor‐derived infection transmission. The remaining 16/30 (53%) recipients received an organ from a nonbacteremic donor with colonization of a nontransplanted organ and were considered at low risk of infection transmission. Proven transmission occurred in 4 of the 14 high‐risk recipients because donor infection was either not recognized, underestimated, or not communicated. These recipients received late, short or inappropriate posttransplant antibiotic therapy. Transmission did not occur in high‐risk recipients who received appropriate and prompt antibiotic therapy for at least 7 days. The safe use of organs from donors with multidrug‐resistant bacteria requires intra‐ and inter‐institutional communication to allow appropriate management and prompt treatment of recipients in order to avoid transmission of infection.

Risk factors for early death in patients awaiting heart-lung or lung transplantation: experience at a single European center.

BACKGROUND Our purpose was to establish whether patients on the waiting list for heart-lung or lung transplantation had different survival rates according to diagnosis and to determine the specific variables responsible for early death. METHODS Between 1988 and 1996, 278 patients were placed on the waiting list for organ transplant. Diagnoses were pulmonary vascular disease in 128, parenchymal disease in 141, and retransplantation in 9 patients. Eighty patients received transplants, 100 patients died awaiting transplantation, and 98 patients are still awaiting transplantation. Univariate and multivariate analyses of risk factors for early death on the waiting list were performed. Patients still listed < or =6 months (n=24), transplanted < or =6 months (n=37), or in the retransplantation group (n=9) were excluded. Of the remaining 208 patients, 52 died < or =6 months and 156 survived >6 months. RESULTS Patients with primary pulmonary hypertension, pulmonary fibrosis, or cystic fibrosis had statistically significantly lower survival rates at 6, 12, and 24 months (31%, 36% and 26%, respectively, at 24 months) than patients with Eisenmengers syndrome and chronic obstructive pulmonary disease (76% and 71%). Patients with Eisenmengers syndrome who died < or =6 months had significantly higher systolic pulmonary artery pressure (134+/-39 vs. 108+/-25 mmHg) and pulmonary vascular resistance (1928+/-1686 vs. 1191+/-730 dyn/sec/cm(-5)) than those who survived longer. Patients with pulmonary fibrosis who died < or =6 months had significantly lower forced vital capacity (36+/-15 vs. 47+/-13% predicted), forced expiratory volume (37+/-14 vs. 48+/-14% predicted), room air PO2 (42+/-11 vs. 50+/-11 mmHg), and room air O2-saturation (78+/-10 vs. 84+/-8%) than those who survived longer. In the multivariate analysis, only the type of pathology was a significant risk factor for death after being on the waiting list < or =6 months. CONCLUSIONS Certain pathologies and variables are risk factors for early death in patients on the waiting list. This information may be used to allocate specific donor organs to patients in greater need.

Circulating biomarkers in pulmonary arterial hypertension: Update and future direction

Pulmonary arterial hypertension (PAH) is a complex disease with a poor prognosis. In recent years, great advances have occurred in our understanding of the pathophysiologic mechanisms underlying the characteristic vascular proliferative lesions, thus allowing the development of several specific drugs. Nevertheless, PAH still presents a high mortality; therefore, early diagnosis and prognostic stratification seem to be of paramount importance in order to choose the best therapeutic strategies. Circulating biomarkers have been proposed as potentially noninvasive and objective parameters for diagnosis, prognosis, and response to therapy. The molecules evaluated to date, including markers of dysfunction and neurohormonal activation, myocardial injury, inflammation and oxidative stress, vascular damage and remodelling, end-organ failure, and gene expression, reflect the complex pathophysiology of PAH. However, not one of these shows all the characteristics of the ideal biomarker; thus, a multiparameter approach is probably desirable. Moreover, future direction could be research of structural proteins specifically expressed in the pathologic tissue that act as disease-specific markers. This report presents an extensive review of circulating biomarkers in PAH and some consideration about potential future direction in this area.