Impact of 3 Major Maintenance Immunosuppressive Protocols on Long-term Clinical Outcomes: Result of a Large Multicenter Italian Cohort Study Including 5635 Renal Transplant Recipients.

BACKGROUND: Although optimization of immunosuppressive schemes in renal transplantation have minimized acute posttransplant complications, long-term outcomes are still not optimal and most of the chronic graft damage is drug-related. Therefore, to define the best long-term maintenance immunosuppressive regimen is of major importance in renal transplantation. To assess this objective, we undertook a large, multicenter cohort study in Italy. METHODS: We retrospectively analyzed data of 5635 patients (enrolled from 1983 to 2012) and we assessed the impact of 3 major immunosuppressive regimens (calcineurin inhibitors+antimetabolites+corticosteroids [CNI+ANT+CS] vs CNI+mammalian target-of-rapamycin (mTOR) inhibitors+CS [CNI+mTOR-I+CS] vs CNI+CS) on long-term clinical outcomes by employing several statistical algorithms. RESULTS: The overall difference in the incidence of outcome over time was not statistically different within the first 5 years of follow-up (P = .13); however, it became significant at 10 years and 20 years (P < .01), with the CNI+CS group showing the lowest cumulative incidence of outcome. Compared with the CNI+ANT+CS group, the CNI+mTOR-I+CS group patients had a significantly higher risk of outcome (hazard ratio [HR], 1.30; P = .024); the difference remained significant and even increased in magnitude after adjustment for potential confounders (HR, 1.38; P = .006). Similarly, patients in the CNI+CS group had a significantly higher risk of the outcome (HR, 1.64; P < .001). CONCLUSION: Our data confirm that CNI+ANT+CS is the "gold standard" therapy in renal transplantation, but, whenever required, the introduction of mTOR-Is instead of ANT may not dramatically modify major clinical outcomes. The use of mTOR-I could be a valuable pharmacologic tool to minimize CNI complications and insure adequate immunosuppression.

Sclerostin and Dickkopf-1 in post-menopausal renal allograft recipients.

BACKGROUND: Age, pre-existing renal osteodistrophy, impaired renal function, and chronic use of immunosuppressive drugs are the main factors involved in the onset and development of bone metabolism disturbances and skeletal alterations occurring after renal transplantation. However, at the state of the art, no reports have analyzed the additional post-menopausal physiological mechanisms associated with the onset and development of bone complications in renal transplant recipients. METHODS: We measured by means of molecular strategies (enzyme-linked immunoassay, chemiluminescence) the serum levels of Sclerostin and Dickkopf-1 (DKK1), two major antagonists of the Wnt/ß-catenin pathway, and several bone resorption/formation biomarkers (N-terminal procollagen type 1, bone-specific alkaline phosphatase, and serum C-terminal telopeptides of type I collagen) in 19 post-menopausal kidney transplant patients and 12 post-menopausal chronic kidney disease patients (CKD group) matched for age and renal function. RESULTS: Our results showed that the levels of both Wnt antagonists were similar in the two study groups (P=.15 and .96, respectively). Additionally, no correlation was found between Sclerostin and DKK1 serum levels in all patients included in the study (R2=0.03, P=.2). After statistical analysis, we found no differences in the bone resorption/formation biomarkers between renal transplant and CKD patients. Multivariate analysis showed that Sclerostin levels were significantly positively correlated with serum phosphorus levels (P=.008) and inversely correlated with renal function (P=.026). Surprisingly, no significant correlation was found between all the analyzed demographic and clinical parameters and DKK1. CONCLUSIONS: Our study demonstrated for the first time that renal transplantation per se and immunosuppressive treatments do not represent additional factors contributing to bone metabolic/biochemical alterations in post-menopausal women. However, our results emphasized that a better preservation of the graft function could significantly slow down the progression of bone metabolic deregulations and prevent clinical bone complications.

Quantification of cytomegalovirus DNA by a fully automated real-time PCR for early diagnosis and monitoring of active viral infection in solid organ transplant recipients.

BACKGROUND: Quantification of cytomegalovirus (CMV) DNA by real-time PCR is currently considered an alternative diagnostic approach for the evaluation of active infection in transplant patients. The pp65 antigenemia assay has been used as reference test for monitoring active CMV infection and guiding preemptive therapy in transplant recipients. However, this assay suffers from some limitations: need for immediate processing of the samples, labour-intensive process, lack of standardization and subjective result interpretation. OBJECTIVES: The aim of this study was to evaluate the performance of a new commercially available real-time PCR assay coupled with a fully automated DNA extraction system (COBAS Ampliprep/COBAS Taqman CMV Test, Roche Diagnostics) for the detection of CMV-DNA in plasma comparing it with pp65 antigenemia assay for monitoring active CMV infection in solid organ transplant recipients (SOTRs). STUDY DESIGN: A total of 266 consecutive samples from 45 SOTRs were monitored with pp65 antigenemia and in parallel with CMV-DNA quantitation by real-time PCR assay. RESULTS: Fifty-eight samples resulted PCR-positive, 163 negative and for 45 samples the CMV-DNA values obtained were below the lower limit of quantification (<150 copies/ml); pp65 antigen was detected in 47 samples and resulted negative in 219 specimens. Concordance between the two evaluations was 76.7%; also a good correlation was observed (r=0.718). Considering the existing treatment criteria based on pp65 antigenemia evaluation corresponding to pp65 levels≥20 positive cells/200,000, preemptive therapy was administered to four asymptomatically infected patients. The corresponding cut-off value of CMV-DNA load calculated for discrimination between self-clearing infections and those requiring therapy was 2500 copies/ml (or 2275 IU/ml). CONCLUSION: The fully automated real-time PCR from Roche provided specific and sensitive results and represented a rapid and simple assay for the evaluation and monitoring of CMV infection in SOTRs. Further studies are required to validate the threshold level for the initiation of preemptive therapy.

Incidence of primary and second cancers in renal transplant recipients: a multicenter cohort study.

Limited data exist about cancer prognosis and the development of second cancers in renal transplant recipients. In a retrospective cohort study on 3537 patients incidence rates of the first and, if any, of a second cancer, and standardized incidence ratios [SIR (95% CI)] were computed. Two hundred and sixty-three (7.5%) patients developed a NMSC, and 253 (7.2%) another type of cancer after a median follow-up of 6.5 and 9.0 years, respectively. A statistically significant excess risk, if compared to an age- and sex-matched reference general population, was observed for Kaposi sarcoma and NMSC, followed by non-Hodgkin lymphoma and carcinoma of cervix uteri; a small number of unusual cancers such as tumors of the salivary glands, small intestine and thyroid also were detected at a level worthy of additional scrutiny. Ten-year survival rate of all noncutaneous cancers was 71.3%, with lower rates for lung carcinoma and non-Hodgkin lymphoma (0% and 41.7%, respectively). Patients with NMSC had an increased risk of developing a second NMSC [SIR 8.3 (7.0-10.0)], and patients with a primary noncutaneous cancer had increased risk of developing a second noncutaneous cancer [SIR 1.8 (1.2-2.8)], if compared to the whole cohort. Our study underscore that the high risk of primary and second cancer in renal transplant recipients, including unusual cancers.

Focal C4d staining in peritubular capillaries and kidney graft survival: results of a retrospective study.

A diffuse positivity (>or=50%) of C4d in kidney graft peritubular capillaries (PTC) significantly correlates with the presence of acute or chronic antibody-mediated rejection. In contrast, significance of a "focal" deposit (10%-50%) is not yet completely defined. The purpose of this study was to assess the impact of focal positive C4d staining on graft survival. We retrospectively reviewed 63 renal biopsies in 54 kidney transplant recipients. They were performed between January 2005 and December 2008 because of graft impairement, namely, a significant increase in serum creatinine and/or urinary protein. C4d positivity was assessed by immunohistochemistry on paraffin-embedded sections, in combination with conventional histopathologic evaluation. Biopsies were classified as negative (<10%) versus with focal (10%-50%) or diffuse deposits (>50%). Cumulative survival was calculated by the Kaplan-Meier method, and Cox regression analysis was used for the multivariate analysis. Focal C4d staining in PTC significantly correlated with worse graft survival (P = .006), similarly to diffuse C4d staining. On multivariate analysis, focal C4d staining prognostically correlated with graft survival, but not recipient or donor age, prior transplantation, number of HLA mismatches or the presence of tubulitis in the sample. Focal C4d staining was associated with worse graft survival.

PTCH1 gene haplotype association with basal cell carcinoma after transplantation.

BACKGROUND: Basal cell carcinoma (BCC) is 10 times more frequent in organ transplant recipients (OTRs) than in the general population. Factors in OTRs conferring increased susceptibility to BCC include ultraviolet radiation exposure, immunosuppression, viral infections such as human papillomavirus, phototype and genetic predisposition. The PTCH1 gene is a negative regulator of the hedgehog pathway, that provides mitogenic signals to basal cells in skin. PTCH1 gene mutations cause naevoid BCC syndrome, and contribute to the development of sporadic BCC and other types of cancers. Associations have been reported between PTCH1 polymorphisms and BCC susceptibility in nontransplanted individuals. OBJECTIVES: To search for novel common polymorphisms in the proximal 5' regulatory region upstream of PTCH1 gene exon 1B, and to investigate the possible association of PTCH1 polymorphisms and haplotypes with BCC risk after organ transplantation. METHODS: Three PTCH1 single nucleotide polymorphisms (rs2297086, rs2066836 and rs357564) were analysed by restriction fragment length polymorphism analysis in 161 northern Italian OTRs (56 BCC cases and 105 controls). Two regions of the PTCH1 gene promoter were screened by heteroduplex analysis in 30 cases and 30 controls. RESULTS: Single locus analysis showed no significant association. Haplotype T(1686)-T(3944) appeared to confer a significantly higher risk for BCC development (odds ratio 2.98, 95% confidence interval 2.55-3.48; P = 0.001). Two novel rare polymorphisms were identified at positions 176 and 179 of the 5'UTR. Two novel alleles of the -4 (CGG)(n) microsatellite were identified. No association of this microsatellite with BCC was observed. CONCLUSIONS: Haplotypes containing T(1686)-T(3944) alleles were shown to be associated with an increased BCC risk in our study population. These data appear to be of great interest for further investigations in a larger group of transplant individuals. Our results do not support the hypothesis that common polymorphisms in the proximal 5' regulatory region of the PTCH1 gene could represent an important risk factor for BCC after organ transplantation.

Bimodal distribution of major cardiovascular events in kidney allograft recipients.

Cardiovascular disease (CVD) is the major cause of death after renal transplantation. We have retrospectively analyzed the incidence and the time of appearance of CVD among 870 consecutive cadaveric kidney transplant recipients, including 143 patients (16.5%) who experienced a fatal or nonfatal event after transplantation. Seventy-four recipients (54%) showed a fatal CVD. Studying the various manifestations, we observed a higher frequency of cardiac events (59% of ischemic heart disease), with 15% cerebrovascular disease and 22% peripheral vascular or aortic disease. In our group, CVDs were distributed in a bimodal manner, with a higher incidence in the first posttransplantation year and a late cluster of CVD at 8 years posttransplantation. The risk of death (hazard function) for CVD increased dramatically during the 8th year after transplantation. This trend of CVD after kidney transplantation may be explained by inadequate evaluation and management of CVD risk factors during waiting list time and, after transplantation, by the cumulative effects of traditional and nontraditional risk factors.

Specific alloantigen self-control by regulatory T cells in organ transplantation: a review.

Multidrug immunosuppressive protocols have increased short-term patient and graft survival rates from 50% to 90% in the past two decades. Unfortunately, chronic graft rejection still remains the main cause of long-term failure and patients must undergo lifelong immunosuppression. The severe side effects such as life-threatening infections, secondary malignancies, and cardiovascular dysfunction all together include roughly 50% of deaths among kidney transplant patients with functioning grafts. Therefore, it should be of crucial importance to reduce immunosuppression and seek induction of specific tolerance to donor alloantigens. Several investigations have suggested that the acquisition of tolerance to self and/or foreign antigens is dependent on the number and function of naturally occurring and acquired regulatory T cells, which can control all aggressive T cells. The regulatory T cells together with their receptors, costimulatory molecules, cytokines, chemokines, and growth factors all contribute to maintain an equilibrium between aggressive and suppressive effector immune responses. As a consequence of increased knowledge, new immunosuppressive approaches based on either alloantigen-specific regulatory T-cell expansion in vivo or in vitro have been proposed to achieve donor-specific transplantation tolerance in kidney allograft recipients. This contribution attempted to summarize knowledge about regulatory T cells and developing methods to induce specific tolerance in kidney transplantation.

Association of functional gene variants in the regulatory regions of COX-2 gene (PTGS2) with nonmelanoma skin cancer after organ transplantation.

BACKGROUND: Overexpression of cyclooxygenase-2 (COX-2), resulting in excessive prostaglandin production, has been observed in human epidermal keratinocytes after ultraviolet B injury, in squamous cell skin carcinoma (SCC), in actinic keratoses, and in the early stages of carcinogenesis in a wide variety of tissues. The dysregulation of COX-2 expression can in part be due to functional changes affecting regulatory elements in the promoter or 3' untranslated region (UTR) of the gene. Two common polymorphisms (-765G-->C, and -1195A-->G) in the promoter region of the COX-2 gene (now PTGS2), and one common polymorphism in the 3' UTR (8473T-->C) have been described, and reported as associated with various malignancies. OBJECTIVES: To determine if common known polymorphisms in the regulatory region of the COX-2 gene (PTGS2) can be associated with nonmelanoma skin cancer (NMSC) predisposition after organ transplantation, to evaluate if cancer risks are associated with specific COX-2 gene (PTGS2) haplotypes containing these polymorphisms, and to identify possible new genetic polymorphisms in the proximal 5' or 3' regulatory regions of the gene associated with disease. METHODS: The frequency of the three polymorphisms was determined in 240 Northern Italian transplant recipient patients (107 cases and 133 controls) with polymerase chain reaction-restriction fragment length polymorphism analysis. The proximal 5' and 3' regulatory regions of the gene were screened by heteroduplex analysis. RESULTS: Stratification by age at transplant and type of tumours [SCC or basal cell carcinoma (BCC)] demonstrated that allele -765C represented a protective factor in BCC cases undergoing transplantation before 50 years of age (CC + CG vs. GG, Fisher exact test P = 0.003). One rare polymorphism, -62C-->G, was detected in the 5' flanking region. The allele frequency of -62G was 0.019, and no difference in genotype between cases and controls was observed. No other variants were found, suggesting that sequence variations in these regions are not likely to contribute to NMSC risk in this population. Haplotype analysis showed that the haplotype containing all major alleles represents a protective factor in patients with SCC undergoing transplantation after 50 years of age [P = 0.009; OR = 0.37 (0.18-0.79)] and that variant -1195A-->G may represent a risk factor in this subgroup of patients [P = 0.01; OR = 4.77 (1.47-16.41)]. Haplotype analysis in patients with BCC revealed that variant -765C might be a protective factor in patients undergoing transplantation before 50 years of age. Variant 8473T-->C, located in the 3' UTR region of the gene, showed no association with NMSC risk after transplantation. CONCLUSIONS: COX-2 common variants -765G-->C and -1195A-->G appear to be associated with risk of NMSC, although in different ways in the SCC and BCC subgroups, indicating that environmental and genetic risk factors may play different roles in the outcome leading to these two phenotypes.

Monitoring of cellular immunity by interferon-gamma enzyme-linked immunosorbent spot assay in kidney allograft recipients: preliminary results of a longitudinal study.

Several efforts have been made in past years to identify markers for patients at heightened risk of acute and chronic immune-mediated allograft rejection. The ex vivo monitoring of cellular immunity by the enzyme-linked immunosorbent spot (ELISPOT) assay has recently emerged as a primary tool in predicting short- and long-term outcomes in kidney allograft recipients. Therefore, we started the systematic application of interferon-gamma (IFN-gamma) ELISPOT assay to measure the frequency of producing IFN-gamma in recipient peripheral blood lymphocytes (PBLs) stimulated with donor lymphocytes before and 7, 14, 21, 28, and 60 days after transplantation. Preliminary results in eight kidney transplant patients indicated that the number of HLA mismatches never correlated with the number of IFN-gamma spots. The frequencies of pretransplantation IFN-gamma spots were positively and significantly correlated with the number of posttransplantation IFN-gamma spots. Clinical outcomes were better among recipients with lower frequencies than those with higher frequencies of pre- and/or posttransplantation IFN-gamma spots. The highest pre- and posttransplantation number of IFN-gamma spots was observed in a patient who developed early acute rejection. Significant increases in the number of IFN-gamma spots preceded the onset of acute rejection events and were decreased by supplemental IV steroid administration. Considering the low number of observations, these preliminary results must be considered cautiously; nevertheless, we are encouraged to extend the systematic application of serial IFN-gamma ELISPOT assay measurements in a more consistent cohort of patients.

A randomized trial of steroid avoidance in renal transplant patients treated with everolimus and cyclosporine.

In this randomized trial renal transplant recipients were treated with basiliximab, everolimus 3 mg/day, low-dose CsA. At transplantation, patients were randomized to stop steroids at the seventh day (group A) or to continue oral steroids in low doses (group B). Of the 113 patients enrolled, 65 were randomized to group A and 68 to group B. All patients were followed for 2 years. During the study 28 (43%) group A patients required reintroduced corticosteroids. One patient died, in group B. The Graft survival rate was 97% in group A and 90% in group B. There were more biopsy-proven rejections in group A (32% vs 16%; P = .044). The mean creatinine clearance was 54 +/- 21 mL/min in group A vs 56 +/- 22 mL/min in group B. Mean levels of serum cholesterol tended to be lower in group A, but the difference was of borderline significance (191 +/- 91 vs 251 +/- 188 mg/dL; P = .07). Vascular thrombosis (0 vs 5) and pneumonia requiring hospitalization (2 vs 7) tended to be more frequent in group B. Only three cases of CMV infection (1 vs 2) occurred. An immunosuppressive therapy with everolimus and low-dose CsA allows one to obtain excellent renal graft survival and stable graft function at 2 years. Early interruption of steroids in patients treated with this regimen may increase the risk of acute rejection, but neither affects graft survival nor graft function, while possibly reducing the risk of hyperlipemia and vascular thrombosis. About 60% of patients given everolimus and low-dose CsA can definitively stop steroids after 1 week.

[Renal transplantation in the North Italy Transplant program (NITp): Organ allocation and results]. / Il trapianto renale nel Nord Italia Transplant program (NITp): assegnazione degli organi e risultati.

Renal transplantation is an effective therapeutic tool for patients with end-stage renal diseases (ESRDs). Data reported in this article summarize the results obtained from 30 years' activity in the North Italy Transplant program (NITp), the first transplant organization in Italy that implemented a donor procurement and organ transplantation network. In the NITp kidney allocation is governed by a computerized algorithm, NITK3, put in place in 1997, aimed at ensuring equity, transparency and traceability during the stages of the allocation decision-making process. The NITp working group has recognized the NITK3 criteria and they are periodically reviewed following the results of the analysis of patients' transplantation odds. The results obtained with the use of the NITK3 algorithm have been very satisfactory: after 6 yrs, a significantly higher percentage of patients at immunological risk (sensitized or waiting for re-transplant), of patients waiting for >3 yrs and of patients with 0-1 HLA A,B,DR mismatches have been transplanted. Moreover, a higher percentage of kidneys were used locally (in a hospital within the procurement area), and this is known to stimulate donor procurement. Finally, we performed a preliminary statistical analysis of transplants carried out from 1998-2002 in 5/16 centers of the NITp area, demonstrating the quality of the NITp program in terms of patient and graft survival, and that donor and recipient age are the variables significantly impacting on transplant results.

An objective method for detecting time-dependent effects in graft survival.

The proportional hazards model has become increasingly important in the analysis of censored survival data after transplantation. Neverthless, in clinical transplantation it is still undefined how the influence of covariates changes over time. The additive regression model is an alternative (or extension) to the Cox model. It results in plots (Aalen plots) that may give information on the effect of covariates over time by way of the cumulative regression function plots. A total of 386 primary cadaveric kidney transplants performed between 1984 and 1996 were included in our analysis. The follow-up period ranged from 24 to 156 months. According to Aalen, an additive regression model was used and plots for the detection of time-dependent effects of covariates were determined. Patients dying with functioning grafts were classed as graft failures. Factors potentially affecting graft outcome, such as sex, donor and recipient's age, HLA A-B match, cold ischaemia time (CIT), delayed graft function (DGF), serum creatinine at 1 month (Cr1), rejection episodes within 3 months (R3), and type of brain death (BD), were considered. The slopes of the plots by donor age, DGF, HLA A-B match, R3, Cr1 and BD appear to have a significant influence throughout the observation period, with different time-dependent effects on graft survival. Slopes for DGF, Cr1, and age of donor are positive (increased hazard), while slopes for HLA match and BD are negative (decreased hazard). Estimated regression functions for DGF, donor age and Cr1 show a prompt slope (within 3 months); the covariate R3 has a clear influence for about 5 years, and then seems to disappear; and BD appears to have a consistent effect over the entire period. The additive regression model with Aalen plots represents a useful technique in the analysis of survival data after kidney transplantation. Some covariates, such as R3, may often lose their effects on graft survival, with a relevant clinical impact. Others have a clear and additive influence over the entire period (BD), while the effects of donor age, DGF and CR1 each appear to have a prompt effect in the outcome.

Tumour necrosis factor-alpha gene polymorphism: implications in kidney transplantation.

In this study we have analysed the TNFA biallelic polymorphism at the -308 position, in 169 kidney recipients that received the graft in a single Italian transplantation facility and we have then correlated the TNFA genotypes with the post-transplant outcome. To assess the cytokine genotypes, a polymerase chain reaction-sequence specific primer (PCR-SSP) methodology has been utilised. By the analysis of the different genotypes, the corresponding TNF-alpha phenotypes and the level of the TNF-alpha production, were deduced: the TNF(*)1/TNF(*)1 genotype gives a low TNF-alpha production level, TNF(*)1/TNF(*) 2 and TNF(*)2/TNF(*)2 genotypes give a high TNF-alpha production level. Out of the one hundred and sixty-nine patients studied, one hundred and twenty-one recipients (72%) had a low TNF-alpha producer phenotype, whereas forty-eight (28%) had a high TNF-alpha producer phenotype. These frequencies were not statistically different from those of the control group. The incidence of acute rejection episodes, vascular damage (grade III degrees of Banff classification), and serum creatinine levels at 1 month, were significantly greater in high TNF-alpha producers (P=0. 048, 0.031 and 0.007 respectively). The logistical regression model indicated that only the high producer genotype and donor age were significantly and independently correlated with acute graft failure (P=0.02 and P=0.013 respectively). This analysis shows that recipient TNFA polymorphism, previously associated with differential production TNF-alpha by in vitro studies could be related to the clinical outcome of kidney transplantation.

Renal adenocarcinoma with lung metastasis in an adolescent.

OBJECTIVE: The finding of a renal adenocarcinoma in a young patient is a rare occurrence. We report on a case of renal adenocarcinoma with lung metastases arising in an 18-year-old girl with non-specific symptoms and normal blood chemistry and urinary analysis. RESULTS AND CONCLUSION: We underscore the aggressive nature of the tumour which grew asymptomatically, giving rise to lymph node and pulmonary metastases.

Comparison between ultrasonography and computerized tomography in the identification of small-sized renal carcinomas.

OBJECTIVES: The increased detection of such small-sized carcinomas has brought a number of new problems regarding the surgical approach to be adopted. We review our experience with 34 patients with small-sized renal carcinomas, comparing the US and CT data with histological findings. METHODS: In a series of 150 cases of renal carcinoma, small sized carcinomas were diagnosed in 34 patients. All patients were examined by US and CT. RESULTS AND CONCLUSION: Five patients presented bifocal carcinomas. CT identified 100% of the small-sized carcinomas, failing only to identify the smaller carcinomas measuring less than 1 cm in diameter in the bifocal carcinoma cases, whereas US identified only 78.3% of the cases. The authors, moreover, mention the problem of multifocal tumours as an argument against performing a partial nephrectomy in the presence of two normally functioning kidneys, and believe it is advisable to reserve such conservative surgery for a selected number of cases.

Renal transplantation and skin diseases: review of the literature and results of a 5-year follow-up of 285 patients.

We present a review of the current literature on skin diseases in renal transplant recipients (RTR) and the results of a 5-year follow-up of 285 patients. Many skin diseases are only an aesthetic and functional cause for interest, but HPV infections and skin cancers are significantly more frequent in RTR than in immunocompetent subjects and can affect a patient's prognosis. For this reason, we feel dermatological surveillance of RTR is necessary for early diagnosis and treatment of all high-risk lesions.

Transbronchial biopsy in the diagnosis of pulmonary infiltrates in immunocompromised patients.

Bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) frequently are performed in the investigation of immunocompromised patients with lung disorders. The risk-benefit ratio of TBB currently is debated, since several authors have found that the less invasive BAL may provide as much information as TBB, with the avoidance of some biopsy-related side effects. We retrospectively evaluated 157 instances of bronchoscopy carried out on 142 immunocompromised patients, with both BAL and TBB performed in every case. Immunosuppressant conditions were HIV infection (79), hematologic malignancies (36), and antirejection therapy in renal transplant recipients (27). Transbronchial biopsy provided a diagnostic yield significantly higher than that obtained by BAL in all categories investigated; diagnostic rates were 77.3% for TBB and 47.6% for BAL (p < 0.001) in patients with HIV infection, 55 and 20% (p < 0.001) in patients with hematologic malignancies, and 57.5 and 27.2% (p < 0.001) in renal transplant recipients. Looking at the whole series, the diagnostic rates of TBB and BAL were 67.5 and 36.3%, respectively (p < 0.001), with a total additional yield of 33% provided by TBB, while in only 2% of cases BAL gave rise to diagnostic information not achieved by TBB. Considering that side effects followed TBB at a negligible rate (2.5%), we believe that TBB should be routinely carried out in these patients once the diagnostic strategy has been oriented to bronchoscopy.