Variability in patterns of BK viral load after renal transplantation

BK virus (BKV) may cause nephropathy in renal transplant patients, resulting in graft dysfunction and possible graft loss. We used a sensitive quantitative BKV assay to monitor plasma BK viral loads in 11 renal transplant patients for periods ranging from 37 to 189 weeks posttransplant. Five patients remained negative for BKV, and 6 developed viremia, including 1 patient with a transient viremia. Of the viremic patients, 2 were diagnosed with BKV nephropathy after increasing serial BK viral loads, prompting a renal biopsy that established the diagnosis. A 3rd patient had high initial BK viral load and biopsy-proven disease that resolved with reduced immunosuppression. Two patients did not develop nephropathy despite persistent viral loads of 10(4) copies/mL. Five of 6 patients experienced viral clearance from the plasma (BK viral load <500 copies/mL), which was associated with their renal function becoming stabilized, and the remaining patient experienced a downward trend in viral load and stable renal function. Thus, the BKV quantitative assay was useful in aiding the diagnosis of BKV nephropathy, monitoring the response to reductions in immunosuppression and identified that some patients can have persistent viremia and still develop stable renal function without specific antiviral therapy.     

High levels of circulating cytomegalovirus DNA reflect visceral organ disease in viremic immunosuppressed patients other than marrow recipients.

Although viremia is a hallmark of disseminated cytomegalovirus (CMV) infection, not all viremic patients have visceral organ CMV disease. We used blot hybridization with a cloned subgenomic probe to quantitate viral DNA in blood leukocytes of 60 viremic patients (25 with solid organ transplants, 20 with AIDS, and 15 marrow recipients) who had different clinical manifestations of CMV infection. The results are expressed as pg of viral DNA/10 micrograms of leukocyte DNA. Patients with AIDS or with solid organ transplants who had CMV visceral organ disease had the largest amounts of viral DNA in their granulocytes (median 632 and 237 pg, respectively). These amounts were significantly greater than those in similar viremic patients without CMV visceral disease (17 and 21 pg; P < 0.005 and 0.002, respectively). All patients in the study with > 150 pg of CMV DNA in their granulocytes had visceral CMV disease. The amounts of viral DNA in granulocytes of AIDS and organ transplant patients with CMV retinitis were low (median 22 pg). Marrow transplant patients were unique in that the amounts of CMV DNA in granulocytes were low whether CMV visceral organ disease was present (17 pg) or absent (14 pg). We conclude that high levels of circulating CMV DNA in viremic AIDS and solid organ transplant patients reflect viral involvement of visceral organs but not the retina. In marrow recipients, the severity of CMV disease, even when fatal, is not reflected quantitatively in peripheral blood leukocytes.     

肾移植术后BK病毒相关性肾病的研究现状

学术背景：肾移植术后并发并发BK病毒感染可以影响移植受者的预后．国外已经对该疾病有了较多的研究。 目的：总结肾移植术后BK病毒相关性肾病的诊断和治疗现状。检索策略：由该论文的研究人员应用计算机检索2000-01/2007-01 Pubmed数据库与肾移植术后BK病毒相关性肾病相关文献．检索词“Renal transplantation：BK virus”，限定文章语言种类为English。共检索到206篇文献，对资料进行初审，纳入标准：与肾移植术后患者并发BK病毒感染有关的文献。排除标准：重复性研究。 文献评价：文献的来源主要是Pubmed数据库，文献类型主要是论著及综述。 资料综合：30％-40％的成人肾移植患者尿中可以发现BK病毒。尽管在肾移植患者中BK病毒有较高的再激活率．但最终仅有较少的一部分患者发展到BK病毒相关性肾病的组织学表现。BK病毒相关性肾病的预后较差，30％-50％的患者最终发展为肾功能衰竭，移植物丢失。由BK病毒引起的移植肾疾病必需依据组织学诊断，由BK病毒引起的移植肾疾病必需依据组织学诊断，除了确定患者感染病毒外，血清学捡验作用不大。评估移植肾活检应该包括电镜检查，特别是肾功能衰竭原因不明确时，电镜能发现细胞核内、胞质内和细胞外的病毒颗粒。BK病毒尿症也能通过对尿样本的核酸杂交法、免疫荧光或ELISA检测病毒抗原。西多福韦是目前较有效的药物，主要缺点是其潜在的肾毒性，其合适的剂量、药代动力学、安全性和耐受性、抗BK病毒活性等这些问题都未得到正式评价，仍需进一步研究。 结论：BK病毒相关性肾病的预后较差，诊断需依据组织学检查。目前BK病毒相关性肾病的治疗主要包括对症支持治疗。减少免疫抑制剂用量。     

Prevalence and infectivity of hepatitis G virus and its strain variant, the GB agent, in volunteer blood donors in Taiwan

BACKGROUND: The prevalence of hepatitis G virus (HGV) and its strain variant, the GB agent (GBV-C) is high in non-virus-inactivated plasma products, but, persistent infection in recipients is relatively low. STUDY DESIGN AND METHODS: Stored samples from transfusion donors and recipients in a prospective study of posttransfusion hepatitis were tested for HGV RNA and antibody to the E2 protein (anti-E2). RESULTS: Thirty-two (2.1%) of the 1500 qualified donors were positive for HGV RNA. Twenty-four persons had received a transfusion of blood from one of these 32 viremic donors. Of these 24 recipients, 3 were positive for HGV RNA before transfusion. Of the remaining 21 recipients, 8 became viremic after transfusion, while the other 13 were not infected. Four of the eight infected recipients were persistently positive for HGV RNA, while four became negative in 1 to 3 years. Three of the four patients with HGV clearance seroconverted to anti-E2 positivity. Comparison of the viral titer, viral sequences at E2, storage period of blood donations, and clinical data in the infected and noninfected recipients revealed no significant differences. However, the noninfected recipients seemed to have a higher prevalence of anti-E2 before transfusion. CONCLUSION: The prevalence of HGV viremia in volunteer blood donors in Taiwan is 2.1 percent, and blood from 0.6 percent of them actually causes HGV infection in the recipients. In half of infected recipients, clearance of HGV occurs. Anti-E2 appears in most recipients whose viremia is cleared.     

Choice of antibody immunotherapy influences cytomegalovirus viremia in simultaneous pancreas-kidney transplant recipients

OBJECTIVE: Simultaneous pancreas-kidney (SPK) transplantation in type 1 diabetic patients requires immunotherapy against allo- and autoreactive T-cells. Cytomegalovirus (CMV) infection is a major cause for morbidity after transplantation and is possibly related to recurrent autoimmunity. In this study, we assessed the pattern of CMV viremia in SPK transplant recipients receiving either antithymocyte globulin (ATG) or anti-CD25 (daclizumab) immunosuppressive induction therapy. RESEARCH DESIGN AND METHODS: We evaluated 36 SPK transplant recipients from a randomized cohort that received either ATG or daclizumab as induction therapy. Patients at risk for CMV infection received oral prophylactic ganciclovir therapy. The CMV DNA level in plasma was measured for at least 180 days using a quantitative real-time PCR. Recipient peripheral blood mononuclear cells were cross-sectionally HLA tetramer-stained for CMV-specific CD8(+) T-cells. RESULTS: Positive CMV serostatus in donors was correlated with a higher incidence of CMV viremia than negative serostatus. In patients at risk, daclizumab induction therapy significantly prolonged CMV-free survival. CMV viremia occurred earlier and was more severe in patients with rejection episodes than in patients without rejection episodes. CMV-specific CD8(+) T-cell counts were significantly lower in patients developing CMV viremia than in those who did not. CONCLUSIONS: Despite their comparable immunosuppressive potential, daclizumab is safer than ATG regarding CMV infection risk in SPK transplantation. ATG-treated rejection episodes are associated with earlier and more severe infection. Furthermore, high CMV-specific tetramer counts reflect antiviral immunity rather than concurrent viremia because they imply low viremic activity. These findings may prove valuable in the discussion on both safety of induction therapy and recurrent autoimmunity in SPK and islet transplantation.     

Ethnic disparities in outcome from posttransplant infections

Black transplant recipients have decreased graft survival and increased rejection rates compared with whites. Because increased rejection rates may lead to more immunosuppression in black recipients, ethnic differences may exist for outcomes of posttransplant infectious complications. All episodes of infection between December 1996 and October 1998 on the transplant services at the University of Virginia Health Sciences Center were prospectively evaluated. Parameters recorded included self-designated ethnicity, demographics, APACHE II scores, laboratory and microbiologic data, immunosuppression, episodes of rejection, and outcome measures. Evaluation of 303 episodes of infection demonstrated an increased mortality rate for white compared with black recipients (19% vs. 3%, P = 0.0006) despite having a similar severity of illness (APACHE II score). Among renal transplant recipients, episodes of infection occurring in black recipients (n = 46) were also associated with a decreased mortality rate versus whites (n = 89) (0% vs. 15%, P = 0.006) and shorter mean length of stay (12 +/- 2 vs. 25 +/- 4 days, P = 0.002) despite similar severity of illness and rejection rates. For posttransplant infections in liver transplant recipients, blacks (n = 23) demonstrated a trend toward decreased mortality (9% vs. 26%, P = 0.07) but equal lengths of stay despite similar APACHE II scores, rejection rates, and age. White liver transplant recipients had an increased incidence of viral infections (15% vs. 0%, P = 0.03). All other infecting organisms were similar. The unexpected finding of a significantly decreased rate of mortality associated with posttransplant infections in black recipients remains largely unexplained but may be related to subtle differences in immune response between racial or ethnic groups.     

无血缘关系供者外周血干细胞移植和骨髓移植治疗白血病的比较

目的比较无血缘关系供者外周血干细胞移植和骨髓移植在造血重建、T 细胞重建、感染、移植物抗宿主病(GVHD)及疗效等的差异。方法 53例白血病患者中,21例接受无血缘关系供者外周血干细胞移植(PBSCT 组),32例接受无血缘关系供者骨髓移植(BMT 组)。统计分析二者移植后白细胞和血小板重建时间、T 细胞重建、感染率、GVHD、白血病复发、无病生存(DFS)情况。结果PBSCT 组和 BMT 组移植后白细胞重建时间分别为(12.43±3.67)天和(16.16±2.99)天(P<0.01),血小板重建时间分别为(14.67±6.19)天和(21.23±8.25)天(P<0.01)。PBSCT 组和 BMT 组移植后1,3,6,9及12个月的 T 细胞重建差异无统计学意义。PBSCT 组和 BMT 组移植后早期感染率分别为42.86%和53.13%(P>0.05)。PBSCT 组与 BMT 组急性 GVHD 的发生率分别为61.90% 和71.885(P>0.05);在可统计的患者中,慢性 GVHD 的发生率在 PBSCT 组和 BMT 组分别为47.06%和43.48%(P>0.05)。PBSCT 组与 BMT 组移植后分别有4例和2例复发,二者复发率差异无统计学意义(P>0.05);PBSCT 组与 BMT 组移植后2年 DFS 率分别为(50.14±12.00)% 和(59.81±8.99)%,二者差异也无统计学意义(P>0.05)。结论无血缘关系供者 PBSCT 后的造血重建比BMT,但二者移植后 T 细胞重建、感染发生率、GVHD 及 DFS 的差异均无统计学意义。     

Dynamics of viremia in early hepatitis C virus infection

BACKGROUND: It is important to characterize viral dynamics in early hepatitis C virus (HCV) infection to further our understanding of viral pathogenesis and the potential for secondary transmission in acute infection through blood transfusion or other routes. STUDY DESIGN AND METHODS: Serial units given by 77 source plasma donors who had evolved from HCV RNA-negative to HCV RNA-positive by nucleic acid amplification technology (NAT) screening with 512-unit pool-NAT or were followed from RNA detection to antibody conversion were tested by individual NAT and quantitative RNA assays. RESULTS: During the ramp-up phase when exponential growth occurs, HCV viral load doubled every 10.8 hours (95% confidence interval [CI], 9.9-12.0). Intermittent viremia was observed before the ramp-up phase in 37 of 50 panels with the earliest detectable viremic bleed occurring 63 days before the estimated onset of ramp-up. The plateau phase or high-titer viremic period that occurs between ramp-up and seroconversion was estimated to last 56.3 days (95% CI, 44.8-67.8). CONCLUSIONS: Intermittent low-level HCV viremia can occur as much as 2 months before the periods of exponential increase in viral load and the high-titer plateau-phase viremia that usually precede seroconversion. Animal inoculation studies are in progress to evaluate if transfusion of low-level viremic plasma can transmit HCV infection.     

Antibody responses and viral load in patients with Crimean-Congo hemorrhagic fever: a comprehensive analysis during the early stages of the infection

This study was performed to assess viral load, viral nucleocapsid (N), and glycoprotein precursor (GPC) antibodies in consecutive samples obtained from Crimean-Congo hemorrhagic fever patients to reveal viral replication kinetics and antiviral immune responses during the early stages of the infection. Among 116 samples from 20 individuals, 43.9% and 76.7% were positive for viral RNA and IgM/IgG antibodies, respectively, whereas both markers could be detected in 22.4%. Mean duration of viremia was 3 days (range: 1–6 days). N-IgM antibodies were identified as the initial serological marker during the infection, becoming detectable in a median of 2–3 days after disease onset, followed by GPC-IgM (4–6 days) and IgG antibodies (5–6 days). Clearance of viremia followed or coincided N-IgM response. Partial S gene sequences amplified in viremic patients were identical or closely related to previously characterized strains and grouped within European lineage I group II viruses via neighbor-joining analysis without significant amino acid substitutions.     

Polyomavirus BK with rearranged noncoding control region emerge in vivo in renal transplant patients and increase viral replication and cytopathology

Immunosuppression is required for BK viremia and polyomavirus BK-associated nephropathy (PVAN) in kidney transplants (KTs), but the role of viral determinants is unclear. We examined BKV noncoding control regions (NCCR), which coordinate viral gene expression and replication. In 286 day-matched plasma and urine samples from 129 KT patients with BKV viremia, including 70 with PVAN, the majority of viruses contained archetypal (ww-) NCCRs. However, rearranged (rr-) NCCRs were more frequent in plasma than in urine samples (22 vs. 4%; P < 0.001), and were associated with 20-fold higher plasma BKV loads (2.0 x 10(4)/ml vs. 4.4 x 10(5)/ml; P < 0.001). Emergence of rr-NCCR in plasma correlated with duration and peak BKV load (R(2) = 0.64; P < 0.001). This was confirmed in a prospective cohort of 733 plasma samples from 227 patients. For 39 PVAN patients with available biopsies, rr-NCCRs were associated with more extensive viral replication and inflammation. Cloning of 10 rr-NCCRs revealed diverse duplications or deletions in different NCCR subregions, but all were sufficient to increase early gene expression, replication capacity, and cytopathology of recombinant BKV in vitro. Thus, rr-NCCR BKV emergence in plasma is linked to increased replication capacity and disease in KTs.     

低剂量环孢素A与肾移植患者术后存活的关系

目的探讨肾移植术后使用低剂量环孢素A（CsA）与肾移植患者术后存活的关系。方法60例行肾移植术的术后患者根据移植术后首次应用CsA剂量分为2组：常规剂量组32例和低剂量组28例。比较两组免疫抑制剂用量下血药浓度、急性排斥反应、肺部感染发生率和人／移植。肾生存率。结果低剂量组术后2、4周CsA平均血药浓度明显低于常规量组（P〈0．001），而在术后2、3、6、12个月CsA平均血药浓度两组间差异均无统计学意义（P均〉0．05）。常规剂量组和低剂量组在移植术后12个月内总的急性排斥反应发生率分别为9．4％、10．7％，两组间差异无统计学意义（P〉0．05）。常规剂量组术后12个月内急性肺部感染发生率为34．4％，而低剂量组为10．7％，两组间差异有统计学意义（P〈0．01）。常规剂量组2年肾移植人／肾生存率为93．8％／90．6％，而低剂量组为92．9％／89．3％，两组比较，差异无统计学意义（P〉0．05）。结论低剂量环孢素A并不增加急性排斥率、亚临床排斥发生率、排斥治疗逆转率和排斥反应的严重程度，但明显降低肺部感染发生率，有利于提高。肾移植患者的术后存活。     

Antiviral therapy for polyomavirus-associated nephropathy after renal transplantation

Polyomavirus-associated nephropathy (PVAN) has recently emerged as an important cause of allograft failure following renal transplantation. The BK virus is the most important polyomavirus associated with this condition. The mainstay of therapy for PVAN is a prompt immunosuppressive dose reduction in conjunction with careful monitoring for BK viraemia. A number of antiviral agents have been tried to help to reduce BK viral replication. So far, there has been only a single randomized controlled study on the use of one of these agents. Pooled data from various small case series did not show significant differences in outcome. Prospective randomized studies with a standardized protocol are urgently required.     

Time to reach tacrolimus maximum blood concentration,mean residence time, and acute renal allograft rejection: an open-label, prospective, pharmacokinetic study in adult recipients

OBJECTIVES: The aims of this study were to determine whether disposition-related pharmacokinetic parameters such as T(max) and mean residence time (MRT) could be used as predictors of clinical efficacy of tacrolimus in renal transplant recipients, and to what extent these parameters would be influenced by clinical variables. METHODS: We previously demonstrated, in a prospective pharmacokinetic study in de novo renal allograft recipients, that patients who experienced early acute rejection did not differ from patients free from rejection in terms of tacrolimus pharmacokinetic exposure parameters (dose interval AUC, preadministration trough blood concentration, C(max), dose). However, recipients with acute rejection reached mean (SD) tacrolimus T(max) significantly faster than those who were free from rejection (0.96 [0.56] hour vs 1.77 [1.06] hours; P < 0.001). Taking into account that neither differences in tacrolimus steady-state clearance nor T(1/2) could explain this unusual finding, we used data from the previous study to calculate MRT from the concentration-time curves. RESULTS: As part of the previous study, 100 patients (59 male, 41 female; mean [SD] age, 51.4 [13.8] years;age range, 20-75 years) were enrolled in the study The calculated MRT was significantly shorter in recipients with acute allograft rejection (11.32 [031] hours vs 11.52 [028] hours; P = 0.02), just like T(max) was an independent risk factor for acute rejection in a multivariate logistic regression model (odds ratio, 0.092 [95% CI, 0.014-0.629]; P = 0.01). Analyzing the impact of demographic, transplantation-related, and biochemical variables on MRT, we found that increasing serum albumin and hematocrit concentrations were associated with a prolonged MRT (P < 0.05). Conversely, serum albumin and hematocrit concentrations were significantly lower in recipients with acute rejection (P < (101). CONCLUSIONS: In this selected population of de novo renal allograft recipients, a shorter tacrolimus T(max) and calculated MRT were associated with a higher incidence of early acute graft rejection. These findings suggest that a shorter transit time of tacrolimus in certain tissue compartments, rather than failure to obtain a maximum absolute tacrolimus blood concentration, might lead to inadequate immunosuppression early after transplantation.     

Reversal of left ventricular diastolic dysfunction after kidney-pancreas transplantation in type 1 diabetic uremic patients

OBJECTIVE: Diastolic function is frequently impaired in diabetic patients. Our aim was to evaluate the effects of glycometabolic control achieved by pancreas transplantation on left ventricular function in uremic type 1 diabetic patients. RESEARCH DESIGN AND METHODS: Left ventricular systolic and diastolic functions were evaluated using radionuclide ventriculography in 42 kidney-pancreas transplant patients and 26 kidney-alone recipients who had similar clinical characteristics before transplantation. Patients were grouped according to 6, 24, and 48 months of follow-up. Control subjects consisted of 20 type 1 diabetic patients. RESULTS: The left ventricular ejection fraction was normal in all of the patients. However, kidney-pancreas transplant patients with 4 years of graft function had a higher ejection fraction (75.7 +/- 1.8%) than kidney-alone patients with 4 years of graft function (65.3 +/- 2.8%, P = 0.02) and type 1 diabetic patients (61.3 +/- 3.7%, P = 0.004). In patients with 4 years of graft function, normal diastolic parameters were evident in kidney-pancreas but not in kidney-alone or in type 1 diabetic patients (peak filling rate: 4.46 +/- 0.15 end diastolic volume (EDV)/s in kidney-pancreas patients vs. 2.73 +/- 0.24 EDV/s [P < 0.01] and 3.39 +/- 0.30 EDV/s [P < 0.01] in kidney-alone and type 1 diabetic patients, respectively; time-to-peak filling rate: 141.9 +/- 7.8 ms in kidney-alone patients vs. 209.4 +/- 13.5 ms in kidney-alone patients [P < 0.01]; peak filling rate/peak ejection rate ratio: 1.10 +/- 0.04 in kidney-pancreas patients vs. 0.81 +/- 0.08 in kidney-alone patients [P < 0.01]). A significant reduction in diastolic dysfunction rate was observed only in kidney-pancreas patients. CONCLUSIONS: Kidney-pancreas transplantation results in complete insulin independence, a better glycometabolic pattern and blood pressure control, an improvement of left ventricular function, and a reversal of diastolic dysfunction.     

BK virus-associated viruria and viremia in a patient with lymphangioleiomyomatosis after lung re-transplantation: A case report and review of the literature on BK virus infection post-lung transplantation

The BK virus (BKV) is a member of the polyomaviridae family of DNA viruses. BKV reactivates under a highly immunosuppressed state and causes renal dysfunction. In renal transplant patients, BKV infection leads to tubular impairment and loss of transplanted kidney grafts. However, few studies have reported on the relationship between BKV and lung transplantation. Adjustment of the dosage of immunosuppressants is needed in some cases, but the treatment method has not been established.Here, we report a case of BKV-associated viruria and viremia in a patient with lymphangioleiomyomatosis (LAM) after lung re-transplantation. A 44-year-old female refractory LAM patient who had undergone lung re-transplantation 3 months earlier was diagnosed with BKV-associated viruria and viremia. Urine cytology indicated decoy cells and the urine and serum polymerase chain reaction test was positive for BKV. As scheduled after re-transplantation surgery, immunosuppressive drugs were progressively reduced. This patient was considered to have experienced spontaneous BKV-associated viremia and viruria. Review of the literature suggested that 17%–42% of BKV-associated viruria cases have been reported after lung transplantation, but cases of BKV-associated nephropathy are rarely reported. Based on the present case, doctors involved in lung transplantation should monitor patients for BKV infection. Decoy cell monitoring by urine cytology is a useful screening method in the follow-up observation after lung transplantation. Early-stage interventions may prevent BKV-associated nephropathy even in patients who have developed BKV viremia, and sirolimus can be administered to patients with histories of BKV infection if they are carefully monitored.     

维持性血液透析患者全麻术后并发症分析

目的 探讨维持性血液透析（maintenance hemodialysis,MHD）患者实施全麻手术（不含肾移植）后并发症发生情况及其影响因素.方法 收集重庆医科大学附属第一医院2009年1月-2013年12月54例行维持性血液透析的终末期肾脏病患者因不同病因实施全麻手术的临床资料,并随机选取相应科室60例同期实施全麻手术的肾功能正常患者的临床资料作对照,回顾性分析其术后并发症的发生情况及影响因素.结果 与肾功能正常患者比较,维持性血液透析患者术后并发症发生率显著升高（48.1％和10.0％,P＜0.01）;最常见并发症为严重高血压（20.4％）,其次为肺部感染（14.8％）、心脏事件（13.0％）;与对照组相比住院时间显著延长,分别为（22.37±13.57）天和（10.82±6.09）天（P＜0.01）;2组术后死亡率无统计学差异（7.4％和1.7％,P=0.188）;原发病为糖尿病肾病、术前低白蛋白血症、术中出血≥400ml与术后并发症增加有关（P均＜0.05）：多变量Logistic回归分析提示原发病为糖尿病肾病是预测维持性血液透析患者术后并发症出现与否的独立危险因素（OR=17.914,95％可信区间：1.164-275.802; P=0.039）.结论 维持性血液透析患者术后住院时间长,并发症发生率高,最常见并发症为高血压、肺部感染、心脏事件,其发生与患者术前低蛋白血症、术中出血多及原发病为糖尿病肾病密切相关,其中原发病为糖尿病肾病是维持性血液透析患者术后出现并发症的独立危险因素.     

Relationship of mycophenolic acid exposure to clinical outcome after hematopoietic cell transplantation

Mycophenolate mofetil is used increasingly to provide immunosuppression after nonmyeloablative allogeneic hematopoietic cell transplantation. There is wide variability in the pharmacokinetics of mycophenolic acid (MPA), the active metabolite, and low concentrations are associated with rejection after organ transplantation. We hypothesized that low MPA was associated with poorer engraftment and a higher incidence of acute graft versus host disease. We evaluated the pharmacokinetics in 87 adult subjects undergoing nonmyeloablative-related and nonmyeloablative-unrelated hematopoietic cell transplantation who were receiving 1 g mycophenolate mofetil orally or intravenously every 12 hours plus cyclosporine (INN, ciclosporin). Subjects with an unbound MPA area under the curve (AUC) from 0 to 6 hours of less than 150 ng . h/mL had a higher cumulative incidence of grade II-IV acute graft versus host disease than subjects with a greater AUC (68% versus 40%, P = .02). An unbound AUC from 0 to 12 hours of less than 300 ng . h/mL was also associated with more frequent acute graft versus host disease (58% versus 35%, P = .05). There was no association between graft versus host disease and trough concentrations (P < or = .62). A higher cumulative incidence of engraftment was associated with total MPA trough concentrations greater than 1 microg/mL (P < .01). All engraftment failures occurred in the cord blood recipients. About one half of subjects were below the unbound AUC target after oral dosing with nearly a 5-fold variability in AUC. Intravenous dosing achieved unbound targets better than oral dosing. The current practice of dosing with 1 g twice daily provides inadequate plasma concentrations in many patients, and doses of at least 3 g/d are likely necessary. Therapeutic monitoring of MPA concentrations with dose adjustment into the therapeutic target appears to be necessary for the most effective use of mycophenolate mofetil.     

ABO incompatibility as an adverse risk factor for survival after allogeneic bone marrow transplantation

BACKGROUND: Graft ABO incompatibility has not been thought to affect patient survival after allogeneic bone marrow transplantation, although it may be associated with prolonged erythroid aplasia and immediate or delayed hemolysis. STUDY DESIGN AND METHODS: A retrospective analysis of a cohort of 292 allogeneic transplant recipients measured survival in a subgroup of ABO-incompatible bone marrow graft recipients. RESULTS: Patients with acute myelogenous leukemia or myelodysplastic syndrome receiving non-T-cell-depleted bone marrow grafts had an 85-percent greater risk of death within 100 days of transplant (relative risk, 1.85, 95% CI, 1.33-2.58; p = 0.003) than comparable patients receiving ABO-compatible grafts. Both ABO major- and minor-mismatched graft recipients were at risk.The increased mortality rate was not due to an increase in graft failure or acute graft-versus-host disease; rather, patients died of multiple-organ failure and sepsis, which is consistent with regimen-related toxicity. This effect was not seen in a larger group of 112 chronic myelogenous leukemia patients undergoing similar treatment. CONCLUSION: ABO incompatibility may be a significant prognostic risk factor after allogeneic bone marrow transplantation in susceptible subgroups of recipients. Care is necessary to design hematopoietic stem and progenitor cell-processing and -transfusion policies to minimize this risk.