Lower prevalence of BK virus infection in African American renal transplant recipients: a prospective study.

BACKGROUND: Because the occurrence of BK virus (BKV) nephritis is far less frequent than BK viremia or viruria, analysis of risk factors for BKV nephritis as an endpoint could lead to erroneous findings. We undertook a prospective study to evaluate the risk factors for the occurrence of BKV infections using BK viruria and viremia as endpoints. METHODS: Two hundred forty renal only transplant recipients were prospectively enrolled into our institutional review board-approved single center study to evaluate various aspects of posttransplant BKV infection. All patients were followed up for a minimum of 6 months posttransplant. RESULTS: Of the 240 subjects, 154 were whites, 61 African Americans, and 25 belonged to other races. A total of 94 developed BKV infection (any degree of BK viruria or viremia) whereas 146 developed no infection. Among these, 33 had BK viruria alone, 61 had BK viremia with viruria and 25 had significant viremia defined as BKV DNA more than 10,000 copies/mL of plasma. Lower proportion of African Americans developed BKV infection, 14 of 61 (23%), as opposed to whites, 67 of 154 (47%). Logistic regression model showed lower risk of any BKV infection in African American recipient race (OR, 0.38; 95% CI, 0.17-0.82; P=0.016) and higher risk of significant BKV infection with occurrence of acute rejection (OR, 3.9; 95% CI, 1.31-11.8; P=0.015). The Kaplan-Meier analysis shows a trend toward greater freedom from BKV infection in African Americans as opposed to other racial groups (P=0.33). CONCLUSION: Renal transplant recipients of African American race had a lower risk of posttransplant BKV infection compared with whites, independent of other confounding risk factors.

Percussion hemoglobinuria - a novel term for hand trauma-induced mechanical hemolysis: a case report.

INTRODUCTION: Extracorpuscular hemolysis caused by mechanical trauma has been well described in relation to lower extremity use, such as in soldiers and runners. Terms such as "march hemoglobinuria", "foot strike hemolysis" and "runners hemoglobinuria" have previously been coined and are easily recalled. Newer cases, however, are being identified in individuals vigorously using their upper extremities, such as drum players who use their hands to strike the instrument. Given the increased recognition of upper extremity-related mechanical hemolysis and hemoglobinuria in drummers, and the use of hand drumming worldwide, we would like introduce a novel term for this condition and call it "percussion hemoglobinuria". CASE PRESENTATION: A 24-year-old Caucasian man presented with reddish brown discoloration of his urine after playing the djembe drum. Urine examination after a rigorous practice session revealed blood on the dipstick, and 0 to 2 red blood cells per high power field microscopically. The urine sample was negative for myoglobulin. Other causes of hemolysis and hematuria were excluded and cessation of drum playing resulted in resolution of his symptoms. CONCLUSIONS: The association of mechanical trauma-induced hemoglobinuria and playing hand percussion instruments is increasingly being recognized. We, however, feel that the true prevalence is higher than what has been previously recorded in the literature. By coining the term "percussion hemoglobinuria" we hope to raise the awareness of screening for upper extremity trauma-induced mechanical hemolysis in the evaluation of a patient with hemoglobinuria.

Successful treatment of BK viremia using reduction in immunosuppression without antiviral therapy.

BACKGROUND: Treatment of BK virus (BKV) infection in renal transplant recipients remains controversial. This retrospective analysis evaluated efficacy and safety of reducing immunosuppression without antiviral therapy. METHODS: This single center analysis included 24 patients diagnosed with BK viremia between September 2001 and December 2003. Sixteen patients (66%) presented with BKV nephritis and eight patients (34%) presented with viremia without evidence of nephritis on renal biopsy. RESULTS: At time of diagnosis, mean plasma BKV DNA (copies/mL) was 460,409 (range 10,205-1,920,691). Mean doses reduction of mycophenolate mofetil and tacrolimus were 44% and 41%, respectively, from time of diagnosis of BKV infection to complete resolution of viremia. A decline in BK viral load was noticed within 15 to 30 days, with successful elimination of viremia over a mean period of 5.8 months (range, 1-9.5). Mean serum creatinine at time of diagnosis of BK viremia was 1.8 mg/dL (range, 1.2-2.8). Mean follow-up period is 30.9 months postdiagnosis. At the most recent visit, serum creatinine was 2.0 mg/dL (range, 1.0-3.6) (P=0.14). With reduction in immunosuppressive therapy, three patients (13%) developed acute cellular rejection and were treated successfully with intravenous bolus steroids. During follow-up, one patient had a relapse of BKV nephritis during pregnancy and lost her graft. After mean follow-up period of 43.5 months posttransplantation, all 24 patients are alive and 23 have a functioning graft. Seventeen patients (71%) have stable or improved graft function. CONCLUSION: Our analysis shows that reduction in immunosuppression therapy alone results in clearance of the BK viremia with good long-term outcome.

BK virus nephritis: risk factors, timing, and outcome in renal transplant recipients.

BACKGROUND: BK virus nephritis (BKVN) has emerged as an important cause of renal transplant failure. Quantified analysis of its timing and clinical course is generally lacking. We have thus quantified the timing, risk factors, evolution of renal function, and transplant graft outcome in renal transplant recipients with BKVN from our center. METHODS: A total of 41 cases of BKVN were diagnosed in 1001 renal and renal/pancreas transplant recipients. There were 2 groups: group I (N= 16), with diagnosis based on renal biopsy alone from January 1996 to August 2001, and group II (N= 25), with diagnosis based on quantitative blood BKV-PCR and biopsy from September 2001 to December 2003. The demographics, the clinical course, immunosuppressive therapy, renal function, and graft outcome were quantified. Donor, recipient, and transplant risk variables were studied using a univariate analysis. Actuarial graft survival was calculated. An immunosuppressive scale created to evaluate the degree of immunosuppression in these patients and its reduction after the diagnosis of BKVN. RESULTS: The median time from transplant to BKVN diagnosis was 318 days (range 48-1356). The actuarial graft survival in patients with BKVN at 6 months, 1, 3, and 5 years was 97%, 90%, 58%, and 47%. The corresponding values for those without BKVN were 94%, 92%, 83%, and 76%, respectively, P < 0.001. Graft loss occurred in 46% of patients. The rate of decline of renal function in group II (N= 25) patients in the 4 months preceding BKVN was rapid (4.8 mL/min/month) and this declined to 0.7 mL/min/month at 3 months' post-BKVN diagnosis, P= 0.004. In those who recovered, the time to stabilization of renal function was a median of 112 days. The immunosuppressive scale score was 7 units at the time of diagnosis of BKVN and decreased to 3.5 units at 3 months' post-BKVN. Reduction in the dose of calcineurin inhibitors but not the overall reduction in dose of immunosuppression correlated with recovery of renal function in these patients. CONCLUSION: BKVN is a relatively late complication of renal transplantation. Despite reduction in immunosuppression, graft loss occurred in 46% of patients. There was a steep decline in renal function in months preceding the diagnosis of BKVN, and reduction in calcineurin inhibitor dose, but not overall immunosuppression, correlated with stabilization of renal function.

Humanized anti-CD20 monoclonal antibody (Rituximab) treatment for post-transplant lymphoproliferative disorder.

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLD) is a consequence of Epstein-Barr virus (EBV) infection and is a B-cell hyperplasia with CD-20 positive lymphocytes. The treatment of PTLD includes reduction/withdrawal of immunosuppression and chemotherapy. This study reports our center experience with humanized monoclonal antibody against CD-20 (Rituximab) for the treatment of PTLD. MATERIAL AND METHODS: Eight cases of PTLD after solid organ transplantation [six kidney, one kidney/pancreas (KP) and one liver] occurred between September 1998 and October 2001. The mean time between transplant and the diagnosis of PTLD was 57.3 months (range 3 months to 10 yr). Five patients underwent cadaveric transplant, five males and six were Caucasians with mean age of 48 yr (range 20-67 yr). RESULTS: The clinical presentation was as follows: lymphadenopathy--5, gastrointestinal bleeding--2 and tonsillar enlargement--1. The diagnosis was made by a lymph node biopsy in five, a gastric ulcer biopsy in two and a tonsillar biopsy in one case. Six of them had polymorphous, two had monoclonal B-cell lymphoma, and all were positive for CD-20. Six were related to EBV, documented by latent membrane protein (LMP) or Epstein-Barr encoded RNA (EBER) staining. Immunosuppression at the time of PTLD diagnosis consisted of tacrolimus in six cases and cyclosporine A (CsA) in two with mycophenolate mofetil (MMF) and azathioprine--3 each and sirolimus--1. Rituximab was administered at a dose of 375 mg/m2 once a week for 4 wk. There were no side effects seen with this therapy. Immunosuppression was reduced in all patients. Complete remission was observed in seven cases (one required two courses). One patient who did not respond received chemotherapy. Patients were followed for a mean period of 22.5 months (range 10-45 months post-PTLD diagnosis. At the last follow-up all eight patients were alive, seven with a functioning graft and one on maintenance dialysis. Three of these patients had been in remission for more than 2.5 yr. CONCLUSION: Rituximab is an effective agent in the treatment of PTLD without the morbidity characteristic of chemotherapy. Chemotherapy should be reserved only for those refractory to Rituximab therapy.

A comparison between recipients receiving matched kidney and those receiving mismatched kidney from the same cadaver donor.

The optimal allocation of cadaveric kidneys for transplantation with reference to human leukocyte antigen (HLA) match and sharing these organs to a distant center remains controversial. The current analysis was performed using the United Network for Organ Sharing (UNOS) database for cadaveric kidney transplants (Tx) between 1988 and 1997. The graft survivals of zero-mismatch (matched) kidneys with the mate (mismatched) kidneys were compared. There were 2385 donors and 4770 Tx. Significant differences in recipient demographics between matched and mismatched Tx were: fewer African-American race (AA) in the matched group (9.0% vs. 21.9%), higher number of previous Tx (25.5% vs. 14.8%) and elevated mean cold ischemia time (24.0 vs. 22.2 h). Post-Tx dialysis requirements were similar (22.8% vs. 24.1%, p = 0.62) and matched kidneys had to travel more distance (920 vs. 232 miles). Using a Cox model, the matched group had a decreased relative hazard of graft failure of 23.0% (p = 0.0002) or 35% (p < 0.0001) with and without censoring for death. There was significantly better graft survival in the matched recipients in all pairs except AA (matched) and non-AA (mismatched). For older donors (> or = 50 years, n = 1508), the matched grafts survival was marginally significant (p =0.05). Matched kidneys have improved survival compared with the mismatched kidneys despite the longer distance traveled. The benefit of mismatched transplants was predominantly seen in non-AA.

Post-transplant renal function in the first year predicts long-term kidney transplant survival.

BACKGROUND: Improvements in long-term kidney graft survival have been recently noted. However, the reasons for this were unclear. This study examined post-transplant renal function within the first year as an independent variable influencing long-term survival. METHODS: The influence of demographic characteristics (age, sex, race); transplant variables (cadaver versus living donor, cold ischemia time, HLA mismatching, delayed graft function and transplant year), and post-transplant variables (immunosuppressive agents for the prevention of acute rejection, clinical acute rejection and post-transplant renal function in the first year) on graft survival were analyzed for 105,742 adult renal transplants between 1988 and 1998. Renal function in the first year was expressed as serum creatinine at six months and one year and delta creatinine (change in serum creatinine between 6 months and 1 year). Graft half-life was used to measure long-term survival. RESULTS: During this 11-year period, the one-year serum creatinine values for cadaver recipients steadily improved, from 1.82 +/- 0.82 mg/dL in 1988 to 1.67 +/- 0.82 mg/dL in 1998 (P < 0.001), as did the graft half-life. There was a progressive decline in graft half-life for each incremental increase of six month, one year and Delta creatinine for living and cadaver donor transplants as well for cadaver transplants with donor age > and < or =50 years. The Relative Hazard (RH) for graft failure was 1.63 (1.61, 1.65; P < 0.0001) with each increment of 1.0 mg/dL of serum creatinine at one year post-transplant and it increased to 2.26 (2.2, 2.31; P < 0.0001) when the Delta creatinine was 0.5 mg/dL. The RH reduction for graft failure was substantially lower for the years 1993, 1996, 1997 and 1998 when post-transplant renal function was not included in the model (P < 0.05). However, the RH reduction per year was not different when post-transplant creatinine was included in the model, 1.01 (0.94 to 1.05; P = 0.89). CONCLUSION: In conclusion, one-year creatinine and Delta creatinine values predict long-term renal graft survival. Recent improvements in graft half-life are related to conservation of renal function within the first year post-transplantation.

Rapid kidney allograft failure in patients with polyoma virus nephritis with prior treatment with antilymphocyte agents.

Interstitial nephritis owing to polyoma virus infection (PVi) mimics acute allograft rejection. The risk factors for graft failure associated with PVi are unknown. This prompted us to analyse the relationship between the use of antilymphocyte agents (ALA) and graft dysfunction in renal transplant recipients with PVi. Renal transplant recipients who were diagnosed to have PVi nephritis at the Medical College of Wisconsin were included in this study. PVi nephritis was confirmed by urine cytology and characteristic renal histological findings in a total of 14 cases. Other viruses were excluded by immunohistochemistry studies. Patients were divided into two groups: Group A (n = 7) received ALA (OKT3/ATGAM) as treatment for presumptive acute rejection and Group B (n = 7) did not receive ALA therapy. The progression of renal function (GFR) was estimated by a 100/ plasma creatinine and an actuarial kidney survival was estimated by the Kaplan-Meier method. The demographics (age, gender, race, retransplant and kidney versus. kidney/pancreas), prior treatment with steroids for presumptive acute rejection, and renal function at the time of PVi diagnosis were similar betwoen groups. The fall in GFR/month was 6 mL/min/month with prior ALA therapy compared with 1 mL/min/month in those who did not receive ALA, p = 0.002. All seven grafts were lost in the ALA group compared with only two of seven grafts in the other group, p = 0.005. The use of ALA was associated with a rapid fall in GFR and graft failure in patients with PVi nephritis. Careful diagnosis of PVi is warranted in renal allograft recipients prior to initiating ALA therapy.