Non-organ-specific and anti-endothelial antibodies in relation to CMV infection and acute rejection in renal transplant recipients.

The presence of non-organ-specific (NOSA) and anti-endothelial antibodies (AECAs) and the onset of rejection in relation to cytomegalovirus (CMV) infection was investigated in 96 renal transplant recipients: 48 CMV pp65-antigenemia-negative (group 1) and 48 positive (group 2). The presence of autoantibodies (autoAbs) was evaluated before and following renal transplantation (first three months) by indirect immunofluorescence. Before transplantation, none of the patients was positive to AECAs, while eight (8.3%) were positive to NOSAs. Post-transplantation, AECA were found in none of patients from group 1 vs. 15/48 (31.2%) from group 2 (p<0.05); NOSAs were detected in 9/48 (18.8%) and 9/48 patients from group 1 and 2, respectively. An acute rejection was diagnosed in ten cases: six of interstitial type (antigenemia-, and AECA-negative; two NOSA-positive); four of vascular type (all of them NOSA-negative, 3/4 antigenemia-, and AECA-positive). CMV infection did not seem to be significantly associated with the appearance of NOSAs, while there was a significant correlation with the occurrence of AECAs. No significant correlation was found between acute rejection and the occurrence of NOSAs, while 75% of the cases of vascular rejection was associated to CMV infection and AECA-positivity, suggesting the pathogenic role of CMV-mediated endothelial damage.

Polyomaviruses BK- And JC-DNA quantitation in kidney allograft biopsies.

BACKGROUND: Polyomavirus-associated nephropathy (PVAN) is one of the most common viral disease affecting renal allograft, with BK being the most frequent causal agent and JCV being considered responsible in <3% of the cases. OBJECTIVES: To quantify polyomaviruses BK and JC load by real-time TaqMan PCR in tissue specimens (renal and ureteral) from kidney transplant recipients. STUDY DESIGN AND METHODS: One-hundred-thirty-eight specimens (125 kidneys, 13 ureters) obtained from 109 patients were evaluated by quantitative real-time PCR for the detection of BKV- and JCV-DNA. Demographic, virological, and histopathological data were collected. RESULTS: BKV-DNA was positive in 32 of 109 patients (29.6%) and JCV-DNA in 20 of 109 patients (18.3%). The highest BK viral loads (>10(4) genome equivalents/cell) were found in two renal samples with histopathologically confirmed PVAN; while JC viral load was >10(4) genome equivalents/cell in one ureteral sample. CONCLUSIONS: Although quantitation of viral DNA on renal allograft biopsies could be complementary to histopathological evaluation and the highest viral load are detectable in renal specimens with PVAN, the identification of a diagnostic cut-off should require further studies.

[Transplantation before dialysis: a statement in favor]. / Il trapianto prima della dialisi: dichiarazione a favore.

Preemptive kidney transplantation is currently considered the optimal initial form of renal replacement therapy not only in terms of clinical outcome (recipient and graft survival) but also in terms of quality of life and social rehabilitation. The benefit of preemptive transplantation is clearly documented by an increasing number of studies based on many single-center experiences and also on the data of international registries. The advantages of receiving a transplant before dialysis (or at least within a few months of its initiation) are statistically evident both in patients receiving cadaver donor grafts and in those receiving living donor grafts. Among the factors that are considered responsible for these favorable results, the avoidance of dialysis-associated morbidity, the lower risk of acute and chronic rejection, the reduced frequency of delayed graft function, and the reduced frequency of cardiovascular mortality seem to play an important role. In the development of a preemptive transplantation program, however, some ethical issues must be carefully considered. At the moment, at least in most Italian regions, there is a persistent discrepancy between the number of kidney patients transplanted yearly and those still on the waiting list. How and when to allocate kidneys harvested from deceased donors to recipients not yet on dialysis remains a matter of debate. Preemptive allocation limited to elderly candidates who accept a double kidney transplant from marginal deceased donors is the most feasible choice at the moment. If a living donor is available, however, preemptive transplantation is mandatory and its implementation mainly depends on the efficacy of nephrologic counseling before the initiation of dialysis.

Monitoring of BK virus replication in the first year following renal transplantation.

BACKGROUND: BK virus-associated nephropathy (BKVAN) is one of the most common viral diseases affecting renal allografts. Screening for viral replication may allow for earlier intervention with reduced allograft loss. A plasma viral load >10(4) copies/mL of BKV DNA is recommended for a presumed diagnosis of BKVAN. METHODS: We monitored BKV load on serum and urine samples by Real-Time TaqMan PCR in 229 renal transplant recipients in the first year post-transplantation. Overall, 2025 serum and 2025 urine samples were evaluated. A graft biopsy was performed in 47/229 patients to investigate the declining renal function. Operating characteristics [sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV)] and receiver operating characteristic (ROC) curve analysis at different viral load values were calculated. RESULTS: Serum BKV viral load was >10(4) in 5/229 patients (2.2%). A histological diagnosis of BKVAN was made in 3/229 patients (1.3%): 3/5 (60.0%) among those with serum viral load >10(4) and 3/4 (75.0%) in those with >1.6 x 10(4). Operating characteristics of a serum BK load of 10(4) for the diagnosis of BKVAN were as follows: sensitivity, 100%; specificity, 99.1%; NPV, 100%; PPV, 59.4%. Specificity and PPV rose to 99.6% and 75.0% when using a cut-off level of 1.6 x 10(4) copies/mL. CONCLUSIONS: The recommended level of BK viraemia of 10(4) copies/mL is useful to identify patients at risk of BKVAN, although specificity and PPV increase by using a cut-off level of 1.6 x 10(4) copies/mL. BK replication may occur in the first 3 months post-transplantation and subsequently recede. Therefore, the temporal profile of BKV replication has to be accurately evaluated and occasionally elevated values should prompt a closer monitoring.

Non-organ-specific autoantibodies in renal transplant recipients: relation to BK virus infection.

Polyomavirus BK reactivation is common in renal transplant recipients and may cause nephropathy with significant graft dysfunction. The induction of anti-double stranded DNA (anti-dsDNA) antibodies by BKV has been described in experimental animals and during primary infection, and has been implicated in the pathogenesis of systemic lupus erythematosus. This study evaluated the occurrence of anti-dsDNA antibodies and non-organ-specific autoantibodies (NOSA) by indirect immunofluorescence before transplantation and at 3 and 6 months post-transplantation in 90 renal transplant recipients and the association with BKV reactivation, demographic and clinical features. Moreover, the relation to HCMV infection, as detected by pp65-antigenemia, was also evaluated. Post-transplantation NOSAs were present in 23/90 (25.6%) and anti-dsDNA antibodies in 17/90 (18.9%). BK viremia was detected in at least one serum sample in 22 patients: 9 anti-dsDNA antibody-positive vs 13 negative (p<0.01). No significant correlation between the occurrence of NOSAs and anti-dsDNA antibodies and demographic and clinical features was found. No significant association with pp65-antigenemia-positivity was found, although antigenemia was positive in 6/23 NOSA-positive patients (26.1%). Although a relation seems to exist between BKV and the occurrence of anti-dsDNA antibodies in renal transplant patients, the lack of correlation with other epidemiological and clinical features does not allow any conclusion. The role of autoimmune response in this context and the relation with other patient-related factors and infectious agents should be further investigated.

Detection and typing of BKV, JCV, and SV40 by multiplex nested polymerase chain reaction.

A multiplex nested polymerase chain reaction (PCR) method was developed for detecting and differentiating simultaneously the DNA of polyomaviruses JC, BK, and SV40 in a single tube. In the first amplification step the same set of primers was used to amplify a conserved DNA region of the large T antigen gene of JCV, BKV, and SV40. The second round was carried out using a set of primers designed to obtain products of different size for each related virus. Subsequently, the sensitivity of the multiplex nested PCR was maximized by optimizing parameters such as primer, magnesium, and dNTP concentrations. The sensitivity of the method ranged between 1 and 10 copies of the polyomavirus genome. The assay was then used for detecting polyomavirus DNA in urine, serum, and biopsy specimens from renal transplant recipients. Based on the results obtained, the multiplex nested PCR developed in our study represents a useful tool for supporting the diagnosis of polyomavirus infection and could be used for epidemiological purposes and to better define the role of polyomaviruses in human pathology.

Urinalysis: do not forget this type of cell in renal transplantation.

Microscopic sediment analysis of urine from a 56-year-old woman who underwent renal transplantation showed many uncommon clusters of rounded and translucent cells containing globular mucous cytoplasmic inclusions (HPF, x400). These cells were bigger than leukocytes and, compared with uroepithelial cells, showed a smaller nucleus to cytoplasm ratio and appeared eosinophilic, being pink rather than azurophilic with Sternheimer-Malbin stain. They were also unlikely to be tubular cells, which are usually smaller, singly distributed and associated with dysmorphic erythrocytes and/or casts and/or a worsening in renal function. A review of the patient's history showed that a pretransplantation urologic surgical treatment, including ileal bladder reconstruction, had been performed. Intestinal epithelial cells should be remembered when examining urinary sediment.

Long-Term Outcomes and Discard Rate of Kidneys by Decade of Extended Criteria Donor Age.

BACKGROUND AND OBJECTIVES: Extended criteria donors represent nowadays a main resource for kidney transplantation, and recovery criteria are becoming increasingly inclusive. However, the limits of this approach are not clear as well as the effects of extreme donor ages on long-term kidney transplantation outcomes. To address these issues, we performed a retrospective study on extended criteria donor kidney transplantation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 647 consecutive extended criteria donor kidney transplantations performed over 11 years (2003-2013) were included. Donor, recipient, and procedural variables were classified according to donor age decades (group A, 50-59 years old [n=91]; group B, 60-69 years old [n=264]; group C, 70-79 years old [n=265]; and group D, ≥80 years old [n=27]). Organs were allocated in single- or dual-kidney transplantation after a multistep evaluation including clinical and histologic criteria. Long-term outcomes and main adverse events were analyzed among age groups and in either single- or dual-kidney transplantation. Kidney discard rate incidence and causes were evaluated. RESULTS: Median follow-up was 4.9 years (25th; 75th percentiles: 2.7; 7.6 years); patient and graft survival were comparable among age groups (5-year patient survival: group A, 87.8%; group B, 88.1%; group C, 88.0%; and group D, 90.1%; P=0.77; graft survival: group A, 74.0%; group B, 74.2%; group C, 75.2%; and group D, 65.9%; P=0.62) and between dual-kidney transplantation and single-kidney transplantation except for group D, with a better survival for dual-kidney transplantation (P=0.04). No difference was found analyzing complications incidence or graft function over time. Kidney discard rate was similar in groups A, B, and C (15.4%, 17.7%, and 20.1%, respectively) and increased in group D (48.2%; odds ratio, 5.1 with A as the reference group; 95% confidence interval, 2.96 to 8.79). CONCLUSIONS: Discard rate and long-term outcomes are similar among extended criteria donor kidney transplantation from donors ages 50-79 years old. Conversely, discard rate was strikingly higher among kidneys from octogenarian donors, but appropriate selection provides comparable long-term outcomes, with better graft survival for dual-kidney transplantation.

New immunosuppressive drugs for prevention and treatment of rejection in renal transplant.

Rejection prevention and control have been pivotal aims of medical research since the time that renal transplant was first developed. While acute rejection rates have generally fallen to 10%-15% at 1 year, chronic rejection and chronic allograft nephropathy (CAN) still erode long-term transplant potential. Furthermore, drug tolerability and their 'secondary' effects other than immunosuppression have become as important as their effectiveness in a recipient population that is increasingly old and burdened by cardiovascular morbidity. We review the state of the art of new immunosuppressive drugs: some of them have already entered clinical practice (e.g., mycophenolate mofetil, anti-CD25 monoclonal antibodies and sirolimus [SRL]); others are at different stages of the pre-registration phase (everolimus, mycophenolic acid, FTY 720, leflunomide-FK 778 and Campath-1H), and many others show promising potential for the future (rituximab, monoclonal antibodies against costimulatory molecules). Especially, new drugs with antiproliferative and antifibrogenic effects (SRL, everolimus, leflunomide and mycophenolic acid) could to be decisive in still challenging areas such as CAN and cardiovascular and neoplastic transplant complications. The key to solving these open issues probably lies in the possibility of relying on a wide repertoire of drugs with different profiles, to be exploited in several associations, and in our capacity to integrate new and old immunosuppressive drugs.

Preferential allocation of marginal kidney allografts to elderly recipients combined with modified immunosuppression gives good results.

BACKGROUND: There is an increasing tendency to allocate kidneys from marginal donors in older recipients. This combination optimizes the uses of an expanded donor pool but demands attention for the higher nephrotoxic sensitivity of the kidney and the increased immunosuppression vulnerability of the elderly recipients. We aimed to reduce these hazards by means of a calcineurin-free induction therapy followed by a maintenance regimen targeted to minimize/withdraw steroid. METHODS: Eighty-eight single (43%) or double (57%) transplant recipients (58.4+/-5.7 years) from 88 marginal donors (67+/-8.3 years) received monoclonal anti-IL-2 receptor antibodies, mycophenolate mofetil (MMF), and steroid. When serum creatinine was less than 2.6 mg/dL, tacrolimus was started and MMF was withdrawn when the tacrolimus trough level was above 15 ng/ml. Steroid was tapered to 5 mg at day 45 and then progressively reduced. RESULTS: Overall patient and graft survival at the first and fourth year were respectively 100 and 96%, and 98 and 79%. Acute rejection rate was 13.6% (12/88), creatinine clearance remained stable (48.2 ml/min at the sixth month, 50.9 ml/min at 48th month). At the first, second, third, and fourth years, 23, 69, 80, and 100% of recipients were off steroids. For those on steroids, mean dose was respectively 2.6 mg/day from month 12. No recipient re-assumed steroids CONCLUSIONS: In the "old-for-old" allocation, the calcineurin-inhibitor avoidance at induction and the steroid withdrawal/minimization during the tacrolimus-based maintenance regimen allow a low acute rejection rate, a stable renal function, and favorable recipient and graft outcomes.

mTOR inhibitors for medical treatment of post-transplantation encapsulating peritoneal sclerosis: a favourable single center experience.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a serious complication in patients on peritoneal dialysis (PD) causing intestinal obstruction. Two different forms of EPS are reported: the classical one observed in patients on PD, and post-transplantation EPS (PostTx-EPS). The first-line therapy of classical and PostTx-EPS remains surgical treatment, but for both the complication rate and mortality are high. Recently, a few cases of EPS were successfully treated with inhibitors of mammalian target of rapamycin (mTORi). The aim of this study was to evaluate PostTx-EPS outcome in our patients, focusing on the potential benefit of mTORi treatment. METHODS: We performed a retrospective analysis on 1,048 kidney transplanted patients at our center between 11/2001 and 12/2011. RESULTS: In the 226 patients treated with PD at any time before grafting, we found 10 cases of PostTx-EPS (prevalence 4.4%). The mean age was 54.9 years (26-69), with a mean time on PD of 83.1 months (33-156). The interval between kidney transplant and EPS diagnosis was 10.5 months (4-18.9). Five of the ten patients were treated after the diagnosis with mTORi, with a favorable outcome in 4/5 cases. This result was substantially independent of surgical and steroid therapy, performed in 9/10 and 10/10 patients respectively. CONCLUSION: EPS is a serious complication but susceptible to improvement if early diagnosed. mTORi represent a useful option for EPS treatment. We too suggest adopting an immunosuppressive protocol based on mTORi, mycophenolate mofetil and steroids in order to prevent PostTx-EPS in transplanted patients at high risk.

Ankylosing spondylitis: a difficult diagnosis in patients on long-term renal replacement therapy.

We report the case of a 48-year-old male, whose musculoskeletal manifestations, previously related to long-term renal replacement therapy (RRT), were diagnosed as ankylosing spondylitis when symptoms changed their pattern on daily hemodialysis (DHD). The patient started RRT in 1981; in 1985 he received a cadaver graft, which failed in 1987. Secondary hyperparathyroidism, amyloid geoids, bilateral carpal tunnel syndrome and high aluminium levels were present. Musculoskeletal pain, reported since 1986, involved feet, heels, hips, shoulders, hands, spine. Symptoms impairing daily life did not improve after parathyroidectomy. He developed chronic hypotension and recurrent atrial fibrillation. In 1994 and 1998, because of thoracic pain, coronarography was performed (normal on both occasions). In June 2000, DHD was started. Equivalent renal clearance increased from 9-12 to 15-17 mL/min. Well-being remarkably improved. In September 2000, musculoskeletal pain worsened and bilateral Achilles tendinitis occurred. The worsening of musculoskeletal symptoms despite the improvements in well-being and other dialysis related symptoms prompted a re-evaluation of the case. The diagnosis of ankylosing spondylitis was based on: history of plantar fasciitis, bilateral Achilles tendinitis, inflammatory spinal pain with limitation of lumbar spine mobility (positive Schober test), radiological evidence of grade 2 bilateral sacroiliitis, presence of HLA-B27. This diagnosis cast light on the episodes of chest pain, explained by enthesopathy at the costosternal and manubriosternal joints and atrial fibrillation, due to HLA-B27 associated impairment in heart conduction. This case exemplifies the difficulty of differential diagnosis of multisystem illness in patients with long RRT follow-up.

Referral of type 1 diabetic patients to a nephrology unit: will pre-emptive transplantation change our life?

BACKGROUND: Type 1 diabetic patients are a small but challenging subset of chronic kidney disease. The new frontiers of pancreas-kidney transplantation may enhance the need for early referral. OBJECTIVE: To analyze the referral pattern of type 1 diabetics to a specialized Nephrology Unit, and to quantify the indications for pancreas or pre-emptive pancreas-kidney transplantation at referral in this population. PATIENTS AND METHODS: Setting of study was a Nephrology Outpatient Unit, dedicated to diabetics, active since 1986; period of study 1991--2002. The main biochemical and clinical parameters were analyzed at referral. Indications for transplantation were put at: serum creatinine (sCr)> or =2 mg/dL or > or =3 mg/dL and/or nephrotic syndrome. Pancreas: lesser degrees of functional impairment without worsening after FK-506 challenge. RESULTS: 90 type 1 diabetics were referred: 48 males, 42 females; median age: 38 (18-65) years; median diabetological follow-up 20 (3-37) years; sCr 1.2 (0.6-7) mg/dL, proteinuria 0.9 (0-12.3) g/day; creatinine clearance: 58 (6-234) ml/min; Hbalc: 8.8% (5.9-14), diastolic blood pressure: 80 (55-100) mmHg, systolic blood pressure: 137.5 (70-180) mmHg. 85.6% had signs of end-organ damage due to diabetes. 67% of the patients had diabetic nephropathy, 20.7% hypertensive with or without diabetic nephropathy. According to the chosen criteria, 30.6% had indications for pancreas-kidney graft (sCr > or = 2 mg/dL), 25.9% considering sCr > or = 3 mg/dL; 28.2% further patients could be considered for isolated pancreas graft. CONCLUSIONS: At referral to the nephrologist, over 50% of type 1 diabetics may have indications for pancreas-kidney or pancreas graft; an earlier multidisciplinary work-up is needed to optimize an early pre-emptive transplant approach.

[A 8-year-forgotten ureteral stent after kidney transplantation: treatment and long-term follow-up]. / Stent ureterale dimenticato in sede per 8 anni dal trapianto renale: trattamento e follow-up a distanza.

INTRODUCTION: Forgotten indwelling ureteral stents can cause significant urological complications. Only few cases are reported after kidney transplantation. MATERIALS AND METHODS: We present a case of a 39-year-old woman, transplanted in 1993 and referred to our Transplant Center 8 years later, because of a serious urinary tract infection with renal function impairment. Abdominal CT scan showed pyelonephritis and hydronephrosis in the transplanted kidney and the presence of a calcific ureteral stent, which had been forgotten in situ for 8 years. The stent was removed, but it was impossible to replace it with a new stent both retrogradely and anterogradely, because of a tight obstruction of the mid ureter. So a uretero-ureteral anastomosis with up urinary tract was performed. RESULTS: No intra- or post-operative complications occurred. At 9 years' follow-up, the patient shows an optimal renal function, with no urinary tract infection. DISCUSSION: A forgotten ureteral stent in a transplanted kidney can cause a lot of complications and can lead to graft loss. The prosthesis may cause an irreversible ureteral damage, so, as in our experience, forgetting a ureteral stent can result in a complex surgery.

Monitoring of inosine monophosphate dehydrogenase activity and expression during the early period of mycophenolate mofetil therapy in de novo renal transplant patients.

Measurement of inosine-monophosphate dehydrogenase (IMPDH) activity or gene expression was used as a further approach in pharmacokinetics (PK)/pharmacodynamic (PD)-guided mycophenolate mofetil (MMF) therapy. Forty-four de novo kidney transplant patients were enrolled; 35 of these completed the study, and were followed for 24 weeks for clinical status, PK parameters, IMPDH activity and IMPDH1/2 gene expression. IMPDH activity and expression were measured in peripheral blood mononuclear cells before transplant and at week 2,4,12 and 24, drawn before (t0) and 2 h (t2 h) after MMF administration. No significant correlation was found between IMPDH activity/expression and PK parameters. For both genes, significant enhancement in t2 h expression was observed, then decreases towards week 24 with a trend following steroid dosages. Seven patients experienced acute rejection (AR) and exhibited significantly higher pre-transplant expression of both IMPDH1 (median 3.42 vs. 0.84; p=0.0025), and IMPDH2 genes (135 vs. 104; p=0.0218) with respect to non-rejecting patients. A significant association was also found between pre-transplant IMPDH1 mRNA and haematological complications (p=0.032). This study suggests that high steroid dosages may influence IMPDH1/2 expression, hampering their use as a PD biomarker, particularly during the early post-transplant period. The measurement of pre-transplant levels of IMPDH1/2 may contribute to prediction of individual drug responsiveness to improve the clinical management of patients in MMF therapy.

Genotyping of polyomavirus BK by Real Time PCR for VP1 gene.

Polyomavirus BK latently persist in different sites, including the renourinary tract, and may reactivate causing nephropathy in renal transplant recipients or hemorrhagic cystitis in bone marrow recipients. Based on the sequence of the VP1 gene, four genotypes have been described, corresponding to the four serologically differentiated subtypes I-IV, with different prevalence and geographic distribution. In this study, the development and clinical validation of four different Real-Time PCR assays for the detection and discrimination of BKV genotypes as a substitute of DNA sequencing are described. 379 BK VP1 sequences, belonging to the main four genotypes, were aligned and "hot spots" of mutation specific for all the strains or isolates were identified. Specific primers and probes for the detection and discrimination of each genotype by four Real-Time PCR assays were designed and technically validated. Subsequently, the four Real-Time PCR assays were used to test 20 BK-positive urine specimens from renal transplant patients, and evidenced a prevalence of BK genotype I, as previously reported in Europe. Results were confirmed by sequencing. The availability of a rapid and simple genotyping method could be useful for the evaluation of BK genotypes prevalence and studies on the impact of the infecting genotype on viral biological behavior, pathogenic role, and immune evasion strategies.

Real-time RT-PCR assay for the quantitation of polyomavirus BK VP1 mRNA levels in urine.

In renal transplant recipients, polyomavirus BK can reactivate resulting in graft nephropathy. Screening for BK virus replication may allow for earlier interventions with reduced allograft loss. The measurement of urinary cell BKV VP1 mRNA for identify viral replication levels at risk of developing nephropathy has been proposed. In this article, the development, optimization, and standardization of a Taqman real-time RT-PCR assay for the quantitation of BKV VP1 mRNA levels in urine is described. Subsequently, the method has been validated on urine specimens obtained from renal transplant recipients. The use of VP1 mRNA measurement as a marker for viral replication and a tool for noninvasive diagnosis of nephropathy should be regarded with great caution, given the potentially limited positive predictive value and the drawbacks associated with the complexity of the real-time RT-PCR assay requiring an expert well trained operator and the relatively poor cost-efficiency ratio.

Human herpes virus 8 infection in kidney transplant patients from an area of northwestern Italy (Piemonte region).

BACKGROUND: Human herpes virus 8 (HHV-8) infection is associated with Kaposi sarcoma (KS) and other neoplastic and non-neoplastic manifestations. A strong association between HHV-8 and KS has been evidenced in transplant recipients, particularly kidney recipients. METHODS: We have investigated the HHV-8 seroprevalence by an immunoenzymatic assay in 408 patients awaiting kidney transplantation and in the corresponding 356 donors; moreover, we have tested for the presence of HHV-8 DNA by nested PCR in available serum samples of the same graft recipients at 6, 12 and >18 months post-transplantation (overall 156 specimens). Associated factors, such as age, sex, area of residence, potential for HHV-8 transmission via organ transplantation and development of KS were also investigated. RESULTS: Twenty (4.9%) of 408 patients and 7 (1.9%) of 356 donors were seropositive. HHV-8 seropositive patients were on average about 6 years older than seronegative individuals. No difference in prevalence by gender was found. Considering the area of residence of seropositive patients, 4/161 (2.48%) were resident in Piemonte vs 16/247 (6.47%) in other areas of Italy (P = n.s.). During the follow-up post-transplantation, HHV-8 DNA was found only in four patients who were seropositive before transplantation, in three cases the corresponding donor was seronegative, in one the corresponding donor was also seropositive and the recipient developed KS. At >18 months post-transplantation, two patients were HHV-8 DNA positive, both were seronegative pre-transplantation and their corresponding donors were seronegative. CONCLUSIONS: HHV-8 seroprevalence in the Piemonte region seems to be low, also in a population of kidney transplant recipients. Based on our data, it does not seem that the immunosuppressive regimen favours the reactivation of HHV-8. Our results do not suggest the possibility of HHV-8 transmission via organ transplantation. Incidence of KS among HHV-8 seropositive patients was very low.