Kidney transplantation using alemtuzumab, belatacept, and sirolimus: Five-year follow-up.

Kidney transplant outcomes are limited by toxicities associated with calcineurin inhibitors and steroids. This trial was conducted to determine whether a costimulation blockade (CoB)-based regimen could achieve acceptable long-term outcomes and graft survival could be maintained solely with CoB. Forty patients underwent alemtuzumab induction followed by belatacept and sirolimus maintenance therapy. Patients were offered weaning to belatacept monotherapy after 1 year and followed for 5 years. Five-year patient and graft survival rates were 100% and 95%, respectively. Graft function remained stable with a mean estimated glomerular filtration rates of 67 ± 21 and 71 ± 19 at 36 and 60 months, respectively. There was no clinical rejection in the first year; subclinical rejection was detected by protocol biopsy in 4 patients. Twelve patients were successfully weaned to belatacept monotherapy. Cytomegalovirus and Epstein-Barr virus reactivations were well controlled, but 9 patients experienced transient BK viremia during the first year. Alemtuzumab produced profound lymphopenia followed by gradual T cell and more rapid B cell reconstitution to a repertoire deviated toward naïve cells with increased regulatory T cells. This regimen effectively prevents allograft rejection without using steroids or calcineurin inhibitors, enriches for naïve cells susceptible to control with CoB, and permits control of rejection with belatacept monotherapy in selected patients.

B cell reconstitution following alemtuzumab induction under a belatacept-based maintenance regimen.

Lymphocyte depletion has been shown to control costimulation blockade-resistant rejection but, in some settings, to exacerbate antibody-mediated rejection (AMR). We have used alemtuzumab, which depletes T and B cells, combined with belatacept and rapamycin and previously reported control of both costimulation blockade-resistant rejection and AMR. To evaluate this regimen's effect on B cell signatures, we investigated 40 patients undergoing this therapy. B cell counts and phenotypes were interrogated using flow cytometry, and serum was analyzed for total IgG, IgM, and donor-specific alloantibody (DSA). Alemtuzumab induction produced pan-lymphocyte depletion; B cells repopulated faster and more completely than T cells. Reconstituting B cells were predominantly naïve, and memory B cells were significantly reduced (P = .001) post repopulation. Two B cell populations with potential immunomodulatory effects-regulatory (CD38hi CD24hi IgMhi CD20hi ) and transitional B cells (CD19+ CD27- IgD+ CD38hi )-were enriched posttransplant (P = .001). Total serum IgG decreased from baseline (P = .016) while IgM levels remained stable. Five patients developed DSAs within 36 months posttransplant, but none developed AMR. Baseline IgG levels in these patients were significantly higher than those in patients without DSAs. These findings suggest that belatacept and rapamycin together limit homeostatic B cell activation following B cell depletion and may lessen the risk of AMR. This regimen warrants prospective, comparative study. ClinicalTrials.gov NCT00565773.

Losartan therapy decreases albuminuria with stable glomerular filtration and permselectivity in sickle cell anemia.

Sickle cell nephropathy begins with hyperfiltration and microalbuminuria and may progress to renal failure. The aim of this study was to determine the effects of losartan on glomerular function and albumin excretion in sickle cell anemia (SCA). Individuals with SCA on hydroxyurea with persistent albuminuria were enrolled in a 1-year study of losartan. Glomerular filtration rate (GFR) measured by iohexol clearance, albumin excretion rate (AER), and fractional clearance of dextran were assessed at baseline, short-term (1-2month), and long-term (≥12month) intervals. Twelve subjects (6 microalbuminuria, 6 macroalbuminuria) completed short-term studies; 8 completed long-term studies. Baseline GFR was 112ml/min/1.73m2 (71-147ml/min/1.73m2). AER decreased significantly at the short-term (median decrease -134 mcg/min, p=0.0063). GFR was not significantly-different at short-term or long-term intervals. Dextran clearance improved for diameters smaller than albumin (<36Å) but not larger sizes. Losartan therapy for ≥1year in sickle nephropathy results in lower albumin excretion with stable GFR. Filtration of neutral molecules ≥36Å was not changed by losartan, suggesting that the effect of losartan is a mechanism other than alteration of glomerular filtration size-selectivity.

Gene-centric association study of acute chest syndrome and painful crisis in sickle cell disease patients.

Patients with sickle cell disease (SCD) present with a wide range of clinical complications. Understanding this clinical heterogeneity offers the prospects to tailor the right treatments to the right patients and also guide the development of novel therapies. Several environmental (eg, nutrition) and nonenvironmental (eg, fetal hemoglobin levels, α-thalassemia status) factors are known to modify SCD severity. To find new genetic modifiers of SCD severity, we performed a gene-centric association study in 1514 African American participants from the Cooperative Study of Sickle Cell Disease (CSSCD) for acute chest syndrome (ACS) and painful crisis. From the initial results, we selected 36 single nucleotide polymorphism (SNPs) and genotyped them for replication in 387 independent patients from the CSSCD, 318 SCD patients recruited at Georgia Health Sciences University, and 449 patients from the Duke SCD cohort. In the combined analysis, an association between ACS and rs6141803 reached array-wide significance (P = 4.1 × 10(-7)). This SNP is located 8.2 kilobases upstream of COMMD7, a gene highly expressed in the lung that interacts with nuclear factor-κB signaling. Our results provide new leads to gaining a better understanding of clinical variability in SCD, a "simple" monogenic disease.

High one year mortality in adults with sickle cell disease and end-stage renal disease.

Adequate pre-dialysis care reduces mortality among end-stage renal disease (ESRD) patients. We tested the hypothesis that individuals with ESRD due to sickle cell disease (SCD-ESRD) receiving pre-ESRD care have lower mortality compared to individuals without pre-ESRD care. We examined the association between mortality and pre-ESRD care in incident SCD-ESRD patients who started haemodialysis between 1 June, 2005 and 31 May, 2009 using data provided by the Centers for Medicare and Medicaid Services (CMS). SCD-ESRD was reported for 410 (0·1%) of 442 017 patients. One year after starting dialysis, 108 (26·3%) patients with incident ESRD attributed to SCD died; the hazard ratio (HR) for mortality among patients with SCD-ESRD compared to those without SCD as the primary cause of renal failure was 2·80 (95% confidence interval [CI] 2·31-3·38). Patients with SCD-ESRD receiving pre-dialysis nephrology care had a lower death rate than those with SCD-ESRD who did not receive pre-dialysis nephrology care (HR = 0·67, 95% CI 0·45-0·99). The one-year mortality rate following an ESRD diagnosis was almost three times higher in individuals with SCD when compared to those without SCD but with ESRD and could be attenuated by pre-dialysis nephrology care.

Transmission of West Nile virus from an organ donor to four transplant recipients.

BACKGROUND: In August 2002, fever and mental-status changes developed in recipients of organs from a common donor. Transmission of West Nile virus through organ transplantation was suspected. METHODS: We reviewed medical records, conducted interviews, and collected blood and tissue samples for testing with a variety of assays. Persons who donated blood to the organ donor and associated blood components were identified and tested for West Nile virus. RESULTS: We identified West Nile virus infection in the organ donor and in all four organ recipients. Encephalitis developed in three of the organ recipients, and febrile illness developed in one. Three recipients became seropositive for West Nile virus IgM antibody; the fourth recipient had brain tissue that was positive for West Nile virus by isolation and nucleic acid and antigen assays. Serum specimens obtained from the organ donor before and immediately after blood transfusions showed no evidence of West Nile virus; however, serum and plasma samples obtained at the time of organ recovery were positive on viral nucleic acid testing and viral culture. The organ donor had received blood transfusions from 63 donors. A review of blood donors and follow-up testing identified one donor who had viremia at the time of donation and who became seropositive for West Nile virus IgM antibodies during the next two months. CONCLUSIONS: Our investigation of this cluster documents the transmission of West Nile virus by organ transplantation. Organ recipients receiving immunosuppressive drugs may be at high risk for severe disease after West Nile virus infection. Blood transfusion was the probable source of the West Nile virus viremia in the organ donor.

Atypical presentation of perforated sigmoid diverticulitis in a kidney transplant recipient with autosomal dominant polycystic kidney disease.

Perforated sigmoid diverticulitis, a complication of colonic diverticulosis commonly associated with autosomal dominant polycystic kidney disease (ADPKD), can be life-threatening in allogeneic kidney transplant recipients in the postoperative period. Immunosuppressive medications not only place the patient at risk for intestinal perforation, but also mask classic clinical symptoms and signs of acute abdomen, and subsequently lead to delayed diagnosis and treatment. We report a case of an ADPKD patient post kidney transplantation presenting with nausea, vomiting, and abdominal pain without signs of peritonitis. Chest x-ray revealed free air under the diaphragm consistent with intestinal perforation. Post kidney transplant recipients with ADPKD presenting with abdominal pain should prompt a search for possible perforated colonic diverticulitis in order to diagnose and treat this life-threatening condition early.

Chronic kidney disease and albuminuria in children with sickle cell disease.

BACKGROUND AND OBJECTIVES: Sickle cell nephropathy begins in childhood and may progress to renal failure. Albuminuria is a sensitive marker of glomerular damage that may indicate early chronic kidney disease (CKD). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The aims of this study were to determine the cross-sectional prevalence and clinical correlates of albuminuria and CKD among children with sickle cell disease (SCD). Over a 10-year period (1995 to 2005) 410 pediatric SCD patients ages 2 to 21 years were enrolled: 261 with hemoglobin SS (HbSS) or HbSß(0) thalassemia (HbSß(0)) and 149 with HbSC or HbSß(+) thalassemia (HbSß(+)). The albumin/creatinine ratio (ACR) of spot-urine specimens and serum creatinine were measured; abnormal albuminuria was defined as urinary ACR ≥ 30 mg/g. RESULTS: The prevalence of abnormal albuminuria was 20.7% (23.0% in HbSS/HbSß(0), 16.8% in HbSC/HbSß(+)). Among HbSS/HbSß(0), abnormal albuminuria was associated with increasing age and lower baseline hemoglobin. GFR, estimated in 189 patients using the updated Schwartz formula, correlated negatively with age (r = -0.27, P = 0.0002). CKD defined according to the Kidney Disease: Improving Global Outcomes study was present in 26.5% (50 of 189) of patients: stage 1 in 27 (14.8%) and stage 2 in 22 (11.6%). In multivariate analysis, age and HbSC/HbSß(+) genotype were associated with CKD. CONCLUSIONS: This is the first study to stage CKD in children with SCD and highlights a high prevalence of albuminuria and glomerular injury early in life. Detecting CKD in childhood could allow for earlier intervention and prevention of renal failure in adulthood.

Assessment of efficacy and safety of FK778 in comparison with standard care in renal transplant recipients with untreated BK nephropathy.

BACKGROUND: BK polyomavirus infection has been reported in 10% to 60% of renal transplant recipients with progression to BK nephropathy (BKN) occurring in 1% to 5% of patients. Graft loss occurs in up to 60% of renal transplant recipients with BKN. Because BK polyomavirus infection is believed, in part, to be a manifestation of overimmunosuppression, the current standard of care involves the reduction of immunosuppressants. This strategy has been associated with clearance of viral load, preservation of renal function, and improvement in graft survival; however, this may come at a risk of rejection. A safe and effective immunosuppressive agent that does not predispose to viral infection is needed in transplantation. METHODS: In a phase 2, proof-of-concept, randomized, open-label, parallel-group, 6-month study in renal transplant patients, FK778 (an investigational immunosuppressant from the malononitrilamides class) was compared with the current standard of care (reduction of immunosuppression) for treatment of newly diagnosed or untreated BKN, which was confirmed by renal biopsy. RESULTS: Demographic characteristics were similar between the two groups, except there were numerically more females in the FK778 group than in the standard care group. Although the treatment with FK778 decreased BK viral load in this study, it was associated with a less favorable rejection profile and renal function and a higher incidence of serious adverse events compared with reduction of immunosuppression. CONCLUSIONS: Data from this study are consistent with the findings of previous studies that found no benefit of drug therapy in the treatment of BKN in kidney transplant recipients.

Glomerular involvement in adults with sickle cell hemoglobinopathies: Prevalence and clinical correlates of progressive renal failure.

Patients with sickle cell anemia (SCA) may develop a glomerulopathy with proteinuria and progressive renal insufficiency, leading to ESRD. Albuminuria is a sensitive marker of glomerular damage in this population and precedes the development of renal insufficiency. For determination of the prevalence of glomerular damage in SCA and the clinical correlates of renal insufficiency, 300 adult patients with SCA were studied (hemoglobin SS = 184; and 116 with other sickling hemoglobinopathies: SC, SD, and S-beta thalassemia); albumin excretion rates (AER) and renal function (Cockroft-Gault formula) were determined, and clinical and hematologic evaluations were conducted. In hemoglobin SS disease, increased AER (micro- and macroalbuminuria) occurred in 68% of adult patients, and macroalbuminuria occurred in 26%. In other sickling disorders, increased AER occurs in 32% of adults, and macroalbuminuria occurs in 10%. The development of graded albuminuria was age dependent, so at 40 yr, 40% of patients with SS disease had macroalbuminuria. There were no differences in hematologic parameters (hemoglobin levels, white blood cell count, percentage of reticulocytes, platelet counts, or lactate dehydrogenase levels) between patients with normoalbuminuria and those with micro- or macroalbuminuria. By multivariate analysis, albuminuria correlated with age and serum creatinine in SS disease but not with BP or hemoglobin levels. In other sickling disorders, albuminuria tended to be associated with age but not with hemoglobin or BP levels. The diastolic BP was lower in patients with SCA than in African American control subjects, and the development of renal insufficiency, which was present in 21% of adults with SS disease, was not accompanied by significant hypertension. It is concluded that glomerular damage in adults with SCA is very common, and a majority of patients with SS disease are at risk for the development of progressive renal failure. The development of micro- and macroalbuminuria is not related to the degree of anemia, suggesting that sickle cell glomerulopathy is not solely related to hemodynamic adaptations to chronic anemia. In contrast to other glomerulopathies, the development of systemic hypertension is uncommon in SS disease with renal insufficiency.

A prospective, open-label trial of sirolimus in the treatment of focal segmental glomerulosclerosis.

Calcineurin inhibitors are effective therapy for steroid-resistant focal segmental glomerulosclerosis (FSGS) but are associated with significant morbidity and nephrotoxicity. Sirolimus is a novel immunosuppressive agent that is structurally related to tacrolimus but demonstrates no long-term nephrotoxicity. For determination of the efficacy of sirolimus in reducing proteinuria, a prospective, open-label trial was conducted of 21 patients with idiopathic, steroid-resistant FSGS. A complete response was defined as <300 mg protein/24 h after 6 mo, whereas a partial response was defined as a 50% reduction in baseline proteinuria. After 6 mo of therapy, sirolimus induced complete remission in four (19%) of 21 patients and partial remissions in eight (38%). Among sirolimus-responsive patients, 6 mo of therapy decreased proteinuria from a mean of 8.8 +/- 1.7 to 2.1 +/- 0.5 g/24 h (P = 0.0003). In responsive patients, GFR was maintained (45 +/- 6 versus 47 +/- 7 ml/min per 1.73 m2 at 6 mo) throughout the study, whereas nonresponders tended to decrease (31 +/- 4 versus 28 +/- 5 ml/min per 1.73 m2). Using dextran sieving analysis, complete or partial response was associated with an increase in the glomerular ultrafiltration coefficient (K(f), 7 +/- 1. versus 8 +/- 0.9 units at 6 mo; P < 0.05). Glomerular permselectivity and K(f) tended to decrease in nonresponders (8.2 +/- 1.9 versus 6.2 +/- 1.3 units at 6 mo; P = 0.07). Patients with complete remission had a higher GFR (45 +/- 6 versus 31 +/- 4 ml/min per 1.73 m2) at the end of 6 mo compared with nonresponders. In patients with steroid-resistant FSGS, sirolimus reduced proteinuria and glomerular pore size and increased K(f) in patients with steroid-resistant FSGS.

Equivalent pharmacokinetics of mycophenolate mofetil in African-American and Caucasian male and female stable renal allograft recipients.

African-American (AA) renal transplant recipients require higher doses of mycophenolate mofetil (MMF) than Caucasians. A hypothesized pharmacokinetic (PK) difference was tested in stable renal transplant recipients. Whole blood was collected before, and 20, 40 and 75 min, and 2, 3, 4, 6, 8 and 12 h after the MMF dose. Mycophenolic acid (MPA) and its glucuronide metabolite (MPAG) were analyzed using HPLC. Analysis of variance was performed for the primary end-points of dose-adjusted PK parameters AUC0-12 and Cmax of MPA using log-transformed values. Differences between races and genders were estimated: 90% confidence intervals (CI) were calculated. Back-transformation gave estimates of the race and gender ratio and their CI. Equivalence of the groups was determined if the 90% confidence limits were included in the interval (0.80, 1.25). The calculated PK parameters were comparable among the four subgroups (Caucasian, AA, Male, Female). The 90% CIs for the ratio of dose-adjusted AUC0-12 of MPA between races were between 89.7 and 112.9%. There were no race, gender or race-by-gender effects (p-values = 0.196) nor differences between diabetics and nondiabetics. This study demonstrates that dosing requirement for MMF in AA and Caucasians is unlikely to be related to different exposures to MPA.

The clinical epidemiology and course of the spectrum of renal diseases associated with HIV infection.

BACKGROUND: While an understanding of the epidemiology and clinical course of HIV-associated nephropathy (HIVAN) is growing, little is known about the risk factors and clinical course of the other renal diseases that may also occur as a complication of HIV infection. This study was undertaken to compare HIVAN to the spectrum of other kidney diseases seen among HIV-infected patients. METHODS: This retrospective cohort study included all HIV-infected patients who underwent renal biopsy during the course of their clinical care at six major medical centers. Demographic and clinical information were abstracted from each patient's clinical record. Time to initiation of renal replacement therapy was compared for patients with lesions other than HIVAN to patients with HIVAN using Cox proportional hazards regression. RESULTS: Eighty-nine patients (47 with lesions other than HIVAN and 42 with HIVAN) were available for inclusion. Patients with lesions other than HIVAN were less likely to be black (37/47 vs. 42/42, P= 0.02), more likely to have a positive hepatitis B surface antigen (10/37 vs. 4/42, P= 0.04), less likely to have the diagnosis of hypertension (24/46 vs. 31/42, P= 0.03), more likely to have a greater creatinine clearance at time of biopsy (60.6 vs. 39.0 cc/min, P= 0.008), and have a greater CD4 lymphocyte count at time of biopsy (287 vs. 187 cells/mL, P= 0.04) compared to patients with HIVAN. Lesions other than HIVAN were associated with a longer time to initiation of renal replacement therapy compared with HIVAN (HR 0.33, 95% CI 0.15-0.71, P= 0.005). Other factors associated with a longer time to renal replacement therapy included higher creatinine clearance at time of biopsy, greater CD4(+) lymphocyte count, the absence of hepatitis C antibody, and the use of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. The type of renal disease (HIVAN vs. other) interacted significantly with HIV-1 RNA level and the use of antiretroviral therapy (P= 0.0001 and 0.006, respectively). Among patients with lesions other than HIVAN, the presence of nondetectable HIV-1 RNA was not associated with a greater risk of progression of renal disease (HR 0.27, P= 0.24). Among patients with HIVAN, because all patients had detectable virus at the time of institution of renal replacement therapy, this highly significant association could not be quantified. Among patients with lesions other than HIVAN, the use of antiretroviral therapy was not associated with the progression to renal replacement therapy (HR 3.29, P= 0.06). Among patients with HIVAN, the use of antiretroviral therapy was associated with a slower progression to renal replacement therapy (HR 0.24, P= 0.03). CONCLUSION: Among HIV-infected patients with renal disease other than HIVAN, viral suppression and the use of antiretroviral therapy are not associated with a beneficial effect on renal function; thus, additional therapeutic strategies may need to be utilized. Because renal histology is associated with prognostic differences, these data provide outcomes information that will improve the clinical utility of renal biopsy among HIV-infected patients with renal disease.