2,8-Dihydroxyadenine Nephropathy Identified as Cause of End-Stage Renal Disease After Renal Transplant.

Adenine phosphoribosyltransferase deficiency is a rare autosomal recessive disorder of uric acid metabolism that leads to formation and excretion of 2,8-dihydroxyadenine into urine. The low solubility of 2,8-dihydroxyadenine results in precipitation and formation of urinary crystals and renal stones. Patients with this disorder usually have recurrent nephrolithiasis and can develop nephropathy secondary to crystal precipitation in the renal parenchyma. The disease is most often underdiagnosed and can recur in renal transplant, causing graft failure. Lack of specific clinical manifestations, chemical and radiologic features identical to those shown with uric acid stones, and lack of awareness among clinicians are among the causes for the underdiagnoses of this treatable disease. Allopurinol, a xanthine dehydrogenase inhibitor, is the mainstay of treatment, supported by high fluid intake and dietary modifications. The possibility of adenine phosphoribosyl transferase deficiency should be considered in all cases of urolithiasis in children, patients with recurrent urolithiasis, and patients with urolithiasis associated with renal failure of unknown cause, including patients with end-stage renal disease and renal transplant recipients. Here, we report a case of a 41-year-old female patient who had a late diagnosis of 2,8-dihydroxyadenine nephropathy-induced end-stage renal disease, made on the native nephrectomy that accompanied the renal transplant, and who had a timely intervention that prevented recurrence in the graft.

Human leukocyte antigen-DR mismatched pediatric renal transplant: patient and graft outcome with different kidney donor sources.

OBJECTIVES: Kidney transplant is well accepted as the optimal therapy for children with end-stage renal disease, and new trends suggest using human leukocyte antigen-DR mismatched grafts. The aim of work was to assess the effect of human leukocyte antigen-DR mismatch on the outcome of pediatric renal transplant recipients, regardless of the source of kidney graft. MATERIALS AND METHODS: According to human leukocyte antigen-DR matching, 104 pediatric patients were categorized into 3 comparable groups. With optimized immunosuppression protocols, long-term graft and patient outcomes were assessed. RESULTS: We found that posttransplant complications were comparable in the 3 groups, without significant increase in the risk of infections or malignancies, especially in the full human leukocyte antigen-DR-mismatched group. Moreover, we found no significant difference in the 3 groups regarding long-term graft or patient survival. CONCLUSIONS: With optimization of immunosuppression, human leukocyte antigen-DR-mismatched donors can be safely accepted for pediatric kidney transplant with comparable long-term patient and graft survival.

Long-acting erythropoietin stimulating agents for persistent anemia after kidney transplant: risk factors and outcome.

OBJECTIVES: Posttransplant anemia is associated with an increased risk of congestive heart failure, left ventricular hypertrophy, and death. The purpose of this study was to evaluate the effect of long-acting erythropoietin-stimulating agents on anemia after kidney transplant. MATERIALS AND METHODS: In 2306 kidney transplant recipients, 250 anemic patients (11%) with stable graft function were followed at the Hamed Al-Essa Organ Transplant Centre (Kuwait) and were assessed for anemia. We enrolled 120 patients into this open-label study in 2 groups: group 1 had treatment with darbepoetin alfa (86 patients) and group 2 had continuous erythropoietin receptor activator (34 patients). RESULTS: Patient age correlated negatively with serum iron level. Serum ferritin correlated negatively with hemoglobin level 6 months after transplant but not at time of transplant. Most patients were women who received their grafts from male donors. The 2 groups were comparable in frequency of rejection and mean hemoglobin and serum albumin levels at 3, 6, 9, and 12 months after transplant. There was no difference between the 2 groups in renal function (estimated glomerular filtration rate); posttransplant complications such as new-onset diabetes after transplant, hypertension, serious bacterial infections, or patient and graft outcomes. CONCLUSIONS: Anemia is an important problem after kidney transplant, and iron use is suboptimal in kidney transplant recipients. Darbepoetin alfa and continuous erythropoietin receptor activator had comparable positive results.

Bilateral chylothorax in a renal transplant recipient: case report and literature review.

Chylothorax is the accumulation of chyle in the pleural cavity as a result of damage to the lymphatic ducts. We treated a young man who was a kidney transplant recipient who had a prior internal jugular vein permanent catheter for hemodialysis, who developed dyspnea and hypoxemia. Chest radiography showed bilateral pleural effusion. Analysis of the white, milky, cloudy, odorless effusion fluid showed cell count > 500/µL; lymphocytes, 60%; total protein, 3.6 mg/dL; urea nitrogen, 45 mg/dL; creatinine, 90 µmol/L; triglycerides, above 2.2 mmol/L (repeatedly high); lactate dehydrogenase, 450 U/L (normal); and cultures, no growth. Magnetic resonance imaging showed thrombosis of the major neck veins, superior vena cava, and azygos vein. Treatment included pleural drains, gut rest, and dietary modification, octreotide, and warfarin. The chylothorax resolved with no relapse. In summary, chylothorax may occur in patients associated with thrombosis of major veins associated with a permanent dialysis catheter.

Successful management of critical illness polyneuropathy and myopathy in renal transplant recipients.

Critical illness polyneuropathy and myopathy commonly occur in patients with multiorgan failure and sepsis. Distal muscle weakness and loss of deep tendon reflexes are usually found, with sparing of the cranial nerve musculature. Many risk factors have been identified, specifically hypoxia, hypotension, hyperpyrexia, and age. Other independent risk factors include female sex, severity of illness, duration of organ dysfunction, renal failure and renal replacement therapy, hyperosmolality, parenteral nutrition, low serum albumin level, duration of intensive care unit stay, vasopressor and catecholamine support, and central neurologic failure. Hyperglycemia also has been identified as an independent risk factor, with important potential affect in terms of prevention. Herein, we report the development of critical illness polyneuropathy and myopathy in 7 of 22 renal transplant recipients who underwent successful ventilator weaning during treatment for bronchopneumonia. This is the first report of critical illness polyneuropathy and myopathy among renal transplant recipients. Clinical suspicion and electrophysiologic studies are tools for early diagnosis. Proper management, including correction of risk factors (especially diabetes) and long-term rehabilitation measures might be beneficial.

Cyclosporine microemulsion formulation (sigmasporin microral) effect as first-line immunosuppressant on renal functions at 3 years.

BACKGROUND: Cyclosporine (CsA) remains a mainstay of immunosuppressive maintenance regimens in developing countries, but its effects on long-term kidney allograft survival are still unclear. Our aim was to assess a generic microemulsion CsA (Sigmasporin) for long-term impact on graft function and patient survival among stable renal transplant patients. METHODS: Over a 36-month period, patients with transplantations from >6 months earlier were maintained on CsA doses of 2-8 mg/kg/d to keep C(2) within the recommended therapeutic range. We assessed 25 efficacy and tolerability parameters of scheduled intervals. RESULTS: Twenty-seven patients (9 female, 18 male) from 6 centers in 4 Middle-Eastern countries were enrolled between 2004 and 2009. Their average age was 35.1 ± 9.8 years, body mass index ranged from 15.7 to 41.2 kg/m(2), and average time from transplantation was 2.2 ± 1.6 years. Within the 36-month observation period the CsA dose was reduced by 17.3% from 2.89 ± 0.88 mg/kg/d to achieve C(2) levels of 600-1000 ng/mL. After 36 months the glomerular filtration rate declined by 8.2% from an overall baseline mean of 72.7 ± 23.5 mL/min/1.73 m(2). It improved in 11.1% of patients and remained unchanged in 44.4%. No new cases of hypertension or diabetes mellitus were reported, and there was 1 case of borderline hyperlipidemia. Graft functions were stable, apart from 2 incidences of CsA nephrotoxicity. Both graft and patient 3-year survival rates were 100%. CONCLUSIONS: On a 3-year basis, Sigmasporin Microral was effective to maintain stable renal functions in kidney transplant patients, with safety and tolerability profiles similar to those reported in the international literature.

Value of (1-3)-ß-d-glucan, Candida mannan and Candida DNA detection in the diagnosis of candidaemia.

This study determined the value of (1,3)-ß-d-glucan (BDG), Candida mannan (MN) and Candida species-specific DNA as surrogates for diagnosis of candidaemia. Thirty-nine patients yielding Candida species in blood cultures were investigated for presence of BDG, MN and Candida species-specific DNA in serum samples. The Candida spp. bloodstream isolates included C. albicans (n = 16), C. tropicalis (n = 10), C. parapsilosis (n = 7), C. glabrata (n = 3) and C. dubliniensis (n = 3). Positivity of the three markers was as follows: Candida DNA for corresponding Candida species, 100%; BDG, 87%; MN, 59%. Despite varying sensitivities of these biomarkers, they provided a useful adjunct to the diagnosis of candidaemia.

Late acute antibody mediated rejection after nine years of renal transplantation.

Acute antibody mediated rejection (AMR) is rarely reported as a long-term com-plication of renal transplantation, and it can present on top of another chronic pathology affecting the graft. A 45-year-old gentleman with chronic kidney disease due to unknown etiology received renal transplantation from his sister with 4 HLA mismatches. He received antithymocte globulin induction therapy and was maintained on steroids, azathioprine (AZA) and cyclosporine A (CsA). Up to eight years post-transplantation he was clinically and biochemically stable. He lost follow-up for about one year, and then presented with nephritic nephrotic syndrome and rise of serum creatinine (SCr.) to 210 µmol/L. Graft biopsy revealed picture suggestive of acute AMR on top of de novo membranoprolipherative glomerulonephritis (MPGN) with focal crescent formation, diffuse immune complex deposition and peritubular capillaries C4d positivity. Anti-HLA donor specific antibodies were highly positive for B and T cells class I and class II. The patient was treated with intravenous immunoglobulin, plasma exchange and anti-CD20 (rituximab). AZA was changed to mycophenolate mofetil and CsA to tacrolimus. He had partial response, but SCr. continued at 220 µmol/L.

Serial soluble CD30 measurements as a predictor of kidney graft outcome.

BACKGROUND: High levels of soluble CD30 (sCD30), a marker for T-helper 2-type cytokine-producing T cells, pre or post-renal transplantation serves as a useful predictor of acute rejection episodes. Over the course of 1-year, we evaluated the accuracy of serial sCD30 tests to predict acute rejection episodes versus other pathologies that affect graft outcomes. PATIENTS AND METHODS: Fifty renal transplant recipients were randomly selected to examine sCD30 on days 0, 3, 5, 7, 14, and 21 followed by 1, 3, 6, and 12 months. The results were analyzed for development of an acute rejection episode, acute tubular necrosis (ATN), or other pathology as well as the graft outcome at 1 year. RESULTS: Compared with pretransplantation sCD30, there was a significant reduction in the average sCD30 immediately posttransplantation from day 3 onward (P<.0001). Patients were divided into four groups: (1) uncomplicated courses (56%); (2) acute rejection episodes (18%); (3) ATN (16%); and (4) other diagnoses (10%). There was a significant reduction in sCD30 immediately posttransplantation for groups 1, 2, and 3 (P<.0001, .004, and .002 respectively) unlike group 4 (P=.387). Patients who developed an acute rejection episode after 1 month showed higher pretransplantation sCD30 values than these who displayed rejection before 1 month (P=.019). All groups experienced significant improvement in graft function over 1-year follow-up without any significant differences. CONCLUSION: Though a significant drop of sCD30 posttransplantation was recorded, serial measurements of sCD30 did not show a difference among subjects who displayed acute rejection episodes, ATN, or other diagnoses.

Posttransplantation calcineurin inhibitor-induced hemolytic uremic syndrome: single-center experience.

INTRODUCTION: Calcineurin inhibitor (CNI) induced HUS, although rare, can be a serious complication of renal transplantation. Classical syndrome of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal injury may not be fully manifested. METHODS: We retrospectively analyzed our data in 950 kidney recipients under follow-up in our center (1994-2008). We reviewed the kidney biopsies performed for these patients to exclude conflicting diagnoses like antibody mediated rejection. RESULTS: HUS was diagnosed in 12 patients (1.26%). None of them had HUS as the original kidney disease. Cyclosporine was the primary immunosuppression in 9 and tacrolimus in 3 patients. The median day of onset was 7 days. Manifestations were anemia (100%), thrombocytopenia (75%), elevated reticulocyte count (62.5%), fragmented red blood cells (8.3%), elevated lactate dehydrogenase (LDH) enzyme (83.3%), increased fibrin degradation product (FDP) (83.3%), reduced haptoglobin level (42.9%) and hyperbilirubinemia (25%). CNI elimination was the first step in the management. Transfusion of fresh frozen plasma (FFP) was used in 10 patients and plasma exchange with FFP in the other two. All grafts recovered function. Cyclosporine or tacrolimus were reintroduction in two patients after complete clinical and laboratory recovery. Both patients developed recurrence of HUS. While the former did not the latter did recover on further treatment of HUS. CONCLUSION: Anemia, thrombocytopenia, elevated LDH and FDP are the most frequent manifestations of HUS. Early CNI elimination and fresh plasma transfusion can revert CNI induced HUS and save the graft. Reintroduction of CNI may be deleterious to the graft and should be avoided.

Toxic tacrolimus blood levels with rifampin administration in a renal transplant recipient.

BACKGROUND: Induction of the hepatic and intestinal cytochrome P450-3A4 system and intestinal P-glycoprotein is an unavoidable consequence of rifampin administration which requires substantial increase in tacrolimus dose when given concurrently. Chronic diarrhea is known to precipitate tacrolimus toxicity irrespective of its cause in renal transplant recipients. CASE REPORT: A 28 years old lady had a second renal transplant when she was 15 years old which is functioning normally. She was maintained on prednisolone, azathioprine, omeprazole and tacrolimus. Tacrolimus was maintained on therapeutic levels (5-7 ng/ml). She developed pyrexia of unknown origin associated with chronic diarrhea. Detailed investigations didn't reach any definite diagnosis. Antituberculous drugs including rifampin were started emperically. During the first four months of antituberculous treatment diarrhea worsened and unexpected high tacrolimus trough blood levels were observed requiring successive dose reduction from 7 mg/day up to 0.5 mg every other day with rise of serum creatinine from 100 to 140 umol/l. Tacrolimus was changed to low dose sirolimus and renal function gradually improved to its baseline while still on rifampin treatment. CONCLUSIONS: We conclude that chronic diarrhea may cause toxic tacrolimus blood levels even in presence of rifampin, this would be due to its significant cytochrome P450-3A4 and P-glycoprotein enzyme inhibitory effect.

Erythema nodosum in renal transplant recipients: multiple cases and review of literature.

We report 4 renal transplant recipients with erythema nodosum. Erythema nodosum is a cutaneous inflammatory reaction located on the anterior aspects of the lower extremities. It may be associated with a wide variety of diseases, including infections (as in Cases 1 and 2), sarcoidosis, rheumatologic diseases, inflammatory bowel diseases (as in Case 3), medications (as in Case 4), autoimmune disorders, pregnancy, and malignancies. Histopathologically, erythema nodosum is the stereotypical example of a mostly septal panniculitis with no vasculitis, and the inflammatory infiltrate in the septa varies with age of the lesion. In early lesions edema, hemorrhage, and neutrophils are responsible for the septal thickening, whereas fibrosis, peri-septal granulation tissue, lymphocytes, and multinucleated giant cells are the main findings in late stage. Etiological management - by anti-tuberculous therapy in Cases 1 and 2, by salazopyrin in Case 3, and by discontinuation of ciprofloxacin in Case 4 - was associated with regression. Erythema nodosum can develop in renal transplant patients who did not receive induction therapy, non-rejecters, and those with steroid-free protocols. Management of erythema nodosum should be directed to the underlying associated condition, which could be tuberculosis, inflammatory bowel disease, or drug related.

Early sirolimus therapy in renal transplant recipients at high risk: is it justified?

BACKGROUND: We studied early sirolimus (SRL) therapy in renal transplant recipients at high risk after administration of antithymocyte globulin or interleukin-2 receptor blockade induction. PATIENTS AND METHODS: In 45 patients, SRL therapy was started within 1 month after transplantation. The primary indications for conversion of treatment from calcineurin inhibitors (CNIs)-mycophenolate mofetil (MMF)-steroid to SRL-MMF-steroid were biopsy-proved rejection (after treatment), CNI toxicity, CNI elimination, and acute tubular necrosis. Pediatric, geriatric, and other patients with medical comorbidities were not excluded. RESULTS: Post-SRL rejection episodes were reported in 22.2% of recipients including 15.6% who were resistant to steroid therapy. Mean (SD) follow-up after SRL therapy was 59.9 (8.1) months. Proteinuria greater than 2 g/d (P = .001), leukopenia (P < .001), hyperlipidemia (P < .001), and transaminases values (P = .02) increased significantly after SRL therapy. Graft survival was 88.8%, and patient survival was 93.3%. There was significant improvement in serum creatinine concentration and estimated creatinine clearance by the end of the study (P < .001). A high incidence of adverse effects and infections was noted post-SRL therapy, and the drug was discontinued in 31% of patients because of multiple adverse effects. At multivariate analysis, age, hypertension, nutritional status, bone marrow suppression, hyperlipidemia, and graft dysfunction were identified as risk factors for worse graft and patient outcome. CONCLUSION: Early treatment with combined SRL-MMF-steroid may be effective as a CNI-free immunosuppression regimen in patients at high risk; however, there is a high rate of adverse effects during long-term follow-up.

Active management of post-renal transplantation BK virus nephropathy: preliminary report.

OBJECTIVE: To assess the efficacy of leflunomide, intravenous immunoglobulins, and ciprofloxacin as active treatment of postrenal transplant BK virus nephropathy (BKVN) in graft outcome at 1 year. PATIENTS AND METHODS: Renal transplant recipients with positive results of 2 BK virus polymerase chain reaction tests of urine and blood underwent graft biopsy to confirm BKVN. If BKVN was diagnosed, antimetabolite therapy (mycophenolate mofetil or azathioprine) was changed to leflunomide therapy accompanied by a course of immunoglobulin and oral ciproflxacin. RESULTS: Of 18 patients evaluated, 72% were men. Nine patients received cadaveric organs, with a mean of 3.6 HLA mismatches. All patients received induction thereapy (61% thymoglobulin), and 61% received antirejection therapy before BKVN was diagnosed. Maintenance immunosuppression therapy was primarily with prednisolone (94%); mycophenolate mofetil, 2 g/d (94%); and tacrolimus (61%). At baseline, mean (SD) creatinine clearance was 35.6 (11.5) mL/min/1.73(2), which decreased to 29.3 (17.3) mL/min/1.73(2) at 1 year (P = .01). Patients were divided into 2 groups of 9 each according to creatinine clearance values. In group 1, baseline value was 44.5 (6.6) mL/min/1.73(2), compared with 25.36 (7.8) mL/min/1.73(2) in group 2, which decreased to 42.66 (12.8) mL/min/1.73(2) (P = .23) and 16.76 (9.0) mL/min/1.73(2) (P = .009), respectively, at 1 year. Three grafts (16.7%) were lost by the end of the study, all in group 2 (P = .03). CONCLUSION: Late diagnosis and intensive immunosuppression predispose to BKVN. Early active treatment of BKVN may improve graft outcome at 1 year posttransplantation.

Low levels of Th1-type cytokines and increased levels of Th2-type cytokines in kidney transplant recipients with active cytomegalovirus infection.

BACKGROUND: Cytomegalovirus (CMV) infection is a major complication after kidney transplantation. It is clear that Th1 and Th2 cell subsets are of major importance in determining the class of immunoprotective function in infectious diseases. Given the strong influence exerted by Th1- and Th2-type immunity on the outcome of infections, we felt it important to elucidate the levels of Th1- and Th2-type cytokines to CMV-related antigens in kidney recipients and to identify antigens that play an essential role in preventing the development of CMV infection and/or disease. METHODS: One hundred twenty subjects were followed for CMV infection by the antigenemia assay. We investigated peripheral blood mononuclear cells (PBMCs) responses to five CMV-related peptide antigens (pp65, gB, pp150, pp28, and pp38). Stimulation index was determined by radioactive thymidine uptake, while the production of Th1-type cytokines (interferon-gamma and tumor necrosis factor-alpha) and Th2-type cytokines (interleukins-4 and -10) were measured by enzyme-linked immunosorbent assay. RESULTS: The levels of Th1-type cytokine production after stimulating PBMCs with CMV-related antigens gB and pp150 resulted in significant decreases in the levels of interferon-gamma, while pp65, pp150, and pp38 produced significant decreases in the level of tumor necrosis factor-alpha between the two groups (P < .05). For Th2-type cytokines only pp28 produced a significant increase in the level of interleukin-10 between the two groups (P < .05). Regarding the Th1:Th2 ratios, a lower Th1-bias was observed among the CMV-positive patients for PBMCs stimulated with three CMV-related antigens (pp65, pp38, and pp28). CONCLUSION: Low levels of Th1-type cytokines and increased levels of Th2-type cytokines upon stimulation with CMV-related peptide antigens were associated with reduced cell-mediated immunity to CMV, thus seeming to correlate with active CMV infections.

Long-term follow-up of 100 high-risk renal transplant recipients converted from calcineurin inhibitors to sirolimus: a single center experience.

While conversion of stable renal transplant recipients (RTR) from calcineurin inhibitors (CNI) to sirolimus (SRL) is safe and effective, it is still under investigation for recent, high-risk cases. We studied the long-term effects of conversion of high-risk subjects maintained on a CNI, mycophenolate mofetil, plus steroid regimen to SRL, mycophenolate mofetil, plus steroid on graft and patient outcomes. We retrospectively reviewed the first 100 RTR converted to SRL treatment over approximately 5 years. The main indications for conversion were biopsy-proven acute rejection (BPAR), CNI toxicity, CNI elimination, and acute-tubular necrosis (ATN). Exclusion criteria were limited to bone marrow suppression. The overall mean +/- SD age was 38.5 +/- 15.6 years, including pediatric and geriatric age groups. Mean +/- SD body mass index (BMI) was 28.99 +/- 8.0 and 40% had a BMI > 30. There were 40% RTR from deceased donors and 60% showed 4 to 6 HLA mismatches. Preconversion total BPAR and steroid-resistant rejection incidences were 35% and 14%, respectively. Mean +/- SD time to start of SRL was 11.9 +/- 22.8 months posttransplantation. Proteinuria > 2 g/d, leukopenia, and hyperlipidemia increased significantly after conversion (P = .001, P = .0003, and P = .0001, respectively). Patient and graft survivals were 95% and 90%, respectively. There was significant improvement in graft function postconversion (P < .0001). There was a high incidence of side effects and cases of SRL discontinuation. Multivariate analysis demonstrated the influence of bone marrow suppression, obesity, hyperlipidemia, nutritional status, proteinuria, and graft function on graft and patient outcomes. We concluded that conversion from CNI to SRL was effective among high-risk RTR, but with a high incidence of adverse events during long-term follow-up.

De-novo [corrected] post renal transplantation inflammatory bowel disease.

Post-renal transplant de-novo inflammatory bowel disease (IBD) may develop despite the presence of mycophenolate mofetil (MMF), a drug used for treatment of IBD, in the immunosuppressive regimen. A 39-year-old man received live unrelated renal transplant, and was started postoperatively on prednisolone, MMF, and tacrolimus, which was changed to sirolimus when he developed diabetes mellitus two months post-transplant. Nine months post-transplant, the patient developed recurrent attacks of bloody diarrhea and ischio-rectal abscesses complicated by anal fistulae not responding to routine surgical treatment. Colonoscopy diagnosed IBD, a Crohn's disease-like pattern. The patient was treated with steroids and 5-aminosalicylic acid (5-ASA) in addition to a two months course of ciprofloxacin and metronidazole. He became asymptomatic and rectal lesions healed within one month of treatment. The patient continued to be asymptomatic, and he maintained normal graft function on the same immunosuppressive treatment in addition to 5-ASA. We conclude that de-novo IBD disease can develop in renal transplant recipients in spite of immunosuppressive therapy including MMF.

Is combined pretransplantation seropositivity of kidney transplant recipients for cytomegalovirus antigens (pp150 and pp28) a predictor for protection against infection?

OBJECTIVE: This study was aimed at detecting antibodies to the antigens which may contribute to protection against cytomegalovirus (CMV) infection after organ transplantation. MATERIALS AND METHODS: A total of 203 kidney transplant patients were enrolled in the study. Based on CMV antigenemia assay, 23 patients were antigen-positive and of the remaining 180 antigen-negative patients, 46 were selected as controls matched for age, gender and source of kidney. The 69 kidney recipients (KR) had CMV antibody due to previous infection and were followed up for a period of 6 months after transplantation for the development of active CMV infections by the antigenemia assay. Antibody responses to five CMV-related peptide antigens (pp65, gB, pp150, pp28 and pp38) were investigated by enzyme immunoassay and their presence was correlated with the results of the CMV antigenemia assay. RESULTS: Of the five CMV-related peptide antigens, only gB antigen showed response to the antibody in 10/23 (43.5%) antigen-positive patients and 9/46 antigen-negative patients and the difference was statistically significant (p = 0.048). On the other hand, there was no significant difference in antibody responses between the antigen-positive and antigen-negative KR to the other four CMV peptide antigens (p > 0.05). However, among the antigen-positive KR there was only 1 patient who had antibodies to both pp150 and pp28 antigen, while among the antigen-negative KR, 22 of 46 (47.8%) had the antibodies (p < 0.001). CONCLUSION: The findings suggest that the combined presence of antibodies against the pp150 and pp28 antigens may indicate a lower risk of CMV reactivation after kidney transplantation.

Detection and monitoring of cytomegalovirus infection in renal transplant patients by quantitative real-time PCR.

OBJECTIVES: To establish a sensitive and specific real-time PCR for quantitation of cytomegalovirus (CMV) DNA in clinical specimens. SUBJECTS AND METHODS: In a prospective study, CMV DNA was quantified in blood samples of 255 kidney recipients with and without CMV-related symptoms between the years 2000 and 2005 in Kuwait. In a selected group of patients, the effect of anti-CMV chemotherapy was monitored by quantitative real-time PCR (qRT-PCR). RESULTS: The established qRT-PCR assay had a sensitivity to detect 30 CMV DNA copies. CMV DNA was detected in 54/255 (24%) patients; of these, 17 (31.5%) were asymptomatic, and 37 patients (68.5%) had symptomatic CMV infection. Sequential blood specimens were collected from all CMV-positive patients and tested by CMV pp65 antigenemia and qRT-PCR assays. There was a moderate positive correlation between the two assays (Pearson's correlation = 0.52). The median CMV viral load measured by qRT-PCR was higher in symptomatic (6.5 x 10(4) copies/ml) than in asymptomatic (185copies/ml) patients (p = 0.001). The estimated cut-off value of CMV DNA for CMV symptoms/disease was > or =800 copies/ml of blood. Testing of sequential samples from patients treated with symptomatic CMV infection showed that the viral load was significantly reduced after 3 weeks of anti-CMV chemotherapy (p = 0.001). CONCLUSION: The reported qRT-PCR is a sensitive method for quantitation of CMV DNA in the blood of kidney recipients and can be useful in monitoring the efficacy of anti-CMV therapy.