Component-resolved analysis of IgA, IgE, and IgG4 during egg OIT identifies markers associated with sustained unresponsiveness.

BACKGROUND: In a previously reported CoFAR study, 55 subjects with egg allergy underwent randomized, placebo-controlled egg oral immunotherapy (eOIT). Active treatment induced desensitization in most and sustained unresponsiveness (SU) in a smaller subset. We hypothesized that component-resolved analysis of IgE, IgG4, IgA, IgA1, and IgA2 may identify potential biomarkers of SU in OIT subjects. METHODS: Longitudinal samples for 51 egg-allergic subjects (37 active and 14 placebo) were available. Egg white (EW)-, ovalbumin (OVA)-, and ovomucoid (OVM)-specific levels of IgA, IgA1, and IgA2 were quantified by ELISA. IgE and IgG4 to these antigens were quantified using ImmunoCAP® . Clinical responders achieved SU to egg; all others were considered nonresponders. Between-group comparisons were made among active and placebo, as well as responders and nonresponders. RESULTS: No placebo subjects achieved responder status. Through month 48, among the 37 active subjects, baseline IgE-OVM was lower in responders (median 3.97 kU/l, n = 19) than in nonresponders (10.9 kU/l, n = 18, P = 0.010). Logistic regression analysis revealed that lower baseline IgE-EW (P = 0.038), IgE-OVM (P = 0.032), and a higher IgG4/IgE-OVM ratio (P = 0.013) were associated with clinical response. Relative increases in IgG4-EW, IgA-EW, and IgA2-EW were observed in responders (P = 0.024, 0.024, and 0.029, respectively). IgG4/IgE, IgA/IgE, and IgA2/IgE ratios for EW and IgA/IgE ratio for OVA were found to be significantly elevated among responders (P = 0.004, 0.009, 0.028, and 0.008, respectively). CONCLUSIONS: Increased IgG4-EW, IgA-EW, and IgA2-EW during eOIT are associated with clinical response to eOIT. Lower pretreatment IgE-EW and IgE-OVM are also associated with SU. Future studies are needed to evaluate and validate these potential biomarkers.

A phase 1 study of heat/phenol-killed, E. coli-encapsulated, recombinant modified peanut proteins Ara h 1, Ara h 2, and Ara h 3 (EMP-123) for the treatment of peanut allergy.

BACKGROUND: Immunotherapy for peanut allergy may be limited by the risk of adverse reactions. OBJECTIVE: To investigate the safety and immunologic effects of a vaccine containing modified peanut proteins. METHODS: This was a phase 1 trial of EMP-123, a rectally administered suspension of recombinant Ara h 1, Ara h 2, and Ara h 3, modified by amino acid substitutions at major IgE-binding epitopes, encapsulated in heat/phenol-killed E. coli. Five healthy adults were treated with 4 weekly escalating doses after which 10 peanut-allergic adults received weekly dose escalations over 10 weeks from 10 mcg to 3063 mcg, followed by three biweekly doses of 3063 mcg. RESULTS: There were no significant adverse effects in the healthy volunteers. Of the 10 peanut-allergic subjects [4 with intermittent asthma, median peanut IgE 33.3 kUA /l (7.2-120.2), and median peanut skin prick test wheal 11.3 mm (6.5-18)]; four experienced no symptoms; one had mild rectal symptoms; and the remaining five experienced adverse reactions preventing completion of dosing. Two were categorized as mild, but the remaining three were more severe, including one moderate reaction and two anaphylactic reactions. Baseline peanut IgE was significantly higher in the five reactive subjects (median 82.4 vs 17.2 kUA /l, P = 0.032), as was baseline anti-Ara h 2 IgE (43.3 versus 8.3, P = 0.036). Peanut skin test titration and basophil activation (at a single dilution) were significantly reduced after treatment, but no significant changes were detected for total IgE, peanut IgE, or peanut IgG4. CONCLUSIONS: Rectal administration of EMP-123 resulted in frequent adverse reactions, including severe allergic reactions in 20%.

Liver transplant outcomes in HIV+ haemophilic men.

Hepatitis C virus infection is the major cause of end-stage liver disease and the major indication for transplantation (OLTX), including among HIV-HCV co-infected individuals. The age of HCV acquisition differs between haemophilic and non-haemophilic candidates, which may affect liver disease outcomes. The purpose of the study was to compare rates of pre- and post-OLTX mortality between co-infected haemophilic and non-haemophilic subjects without hepatocellular cancer participating in the Solid Organ Transplantation in HIV Study (HIV-TR). Clinical variables included age, gender, race, liver disease aetiology, BMI, antiretroviral therapy, MELD score, CD4 + cell count, HIV RNA PCR and HCV RNA PCR. Time to transplant, rejection and death were determined. Of 104 HIV-HCV positive subjects enrolled, 34 (32.7%) underwent liver transplantation, including 7 of 15 (46.7%) haemophilic and 27 of 89 (30.3%) non-haemophilic candidates. Although haemophilic subjects were younger, median 41 vs. 47 years, P = 0.01, they were more likely than non-haemophilic subjects to die pre-OLTX, 5 (33.3%) vs. 13 (14.6%), P = 0.03, and reached MELD = 25 marginally faster, 0.01 vs. 0.7 years, P = 0.06. The groups did not differ in baseline BMI, CD4, detectable HIV RNA, detectable HCV RNA, time to post-OLTX death (P = 0.64), graft loss (P = 0.80), or treated rejection (P = 0.77). The rate of rejection was 14% vs. 36% at 1-year and 36% vs. 43% at 3-year, haemophilic vs. non-haemophilic subjects, respectively, and post-OLTX survival, 71% vs. 66% at 1-year and 38% vs. 53% at 3-year. Despite similar transplant outcomes, pretransplant mortality is higher among co-infected haemophilic than non-haemophilic candidates.

Improved survival with recent Post-Transplant Lymphoproliferative Disorder (PTLD) in children with kidney transplants.

Post-transplant lymphoproliferative disorder (PTLD) has been associated with high mortality, but recent anecdotal survival appeared better. From 1988 to 2010, the NAPRTCS registry had 235 registered PTLD cases. We sent a special 25-point questionnaire study to the NAPRTCS centers with the most recent 150 cases to obtain additional follow-up data not collected in the master registry, our objective being to determine the recent outcomes after PTLD and determine prognostic factors. We received 92 completed responses, in which only 12 (13%) deaths were reported, 2 from nonmedical causes, 10 with a functioning graft. Kaplan-Meier-calculated patient survival was 90.6% at 1 year and 87.4% at 3, 4 and 5 years post-PTLD. Graft survival post-PTLD was 81.8% at 1 year, 68.0% at 3 years and 65.0% at 5 years. Seven patients received a retransplant after PTLD, with no PTLD recurrence reported. Using all 235 PTLD cases, the covariates associated with better patient survival were more recent year of PTLD diagnosis (adjusted hazard ratio AHR 0.86, p < 0.001), and with worse survival were late PTLD (AHR 1.98, p = 0.0176) and patient age above 13 at PTLD (AHR 3.43, p value 0.022). In children with kidney transplants, patient survival has improved with more recent PTLDs.

Variables affecting estimated glomerular filtration rate after renal transplantation in children: a NAPRTCS data analysis.

Short-term graft survival has improved in renal transplants without significant effect on long-term graft survival. As GFR decline precedes graft loss, an understanding of variables affecting eGFR after TX may help improve graft survival. NAPRTCS data were analyzed to assess effects of donor, recipient, and other variables on Schwartz eGFR after transplantation. For 8438 children with a functioning graft at day 30, data were censored for children dying with a functioning graft, and those with <3 yr follow-up. Multivariate linear regression and repeated measures analyses identified factors related to eGFR at day 30 after TX and during follow-up. Young, female, non-black, children without ATN and acute rejection in the first 30 days, TX after 1995, those with better eGFR at day 30, and receiving tacrolimus had better long-term eGFR. Transplant from ideal (6-35 yr) donors had best short-term eGFR, young donors (<5 yr) had lower eGFR and poor graft survival. After one yr, eGFR improved in surviving grafts of young donors and matched ideal donors. Acute rejection, BP medications, and hospitalizations in prior six months had negative association with subsequent eGFR. Regardless of variables, eGFR deteriorated with time. Slope of eGFR decline has not changed in the recent era indicating the need for innovative therapies.

Treatment-dependent loss of polyfunctional CD8+ T-cell responses in HIV-infected kidney transplant recipients is associated with herpesvirus reactivation.

Antiretroviral-therapy has dramatically changed the course of HIV infection and HIV-infected (HIV(+)) individuals are becoming more frequently eligible for solid-organ transplantation. However, only scarce data are available on how immunosuppressive (IS) strategies relate to transplantation outcome and immune function. We determined the impact of transplantation and immune-depleting treatment on CD4+ T-cell counts, HIV-, EBV-, and Cytomegalovirus (CMV)-viral loads and virus-specific T-cell immunity in a 1-year prospective cohort of 27 HIV(+) kidney transplant recipients. While the results show an increasing breadth and magnitude of the herpesvirus-specific cytotoxic T-cell (CTL) response over-time, they also revealed a significant depletion of polyfunctional virus-specific CTL in individuals receiving thymoglobulin as a lymphocyte-depleting treatment. The disappearance of polyfunctional CTL was accompanied by virologic EBV-reactivation events, directly linking the absence of specific polyfunctional CTL to viral reactivation. The data provide first insights into the immune-reserve in HIV+ infected transplant recipients and highlight new immunological effects of thymoglobulin treatment. Long-term studies will be needed to assess the clinical risk associated with thymoglobulin treatment, in particular with regards to EBV-associated lymphoproliferative diseases.

HIV-infected liver and kidney transplant recipients: 1- and 3-year outcomes.

Improvements in human immunodeficiency virus (HIV)-associated mortality make it difficult to deny transplantation based upon futility. Outcomes in the current management era are unknown. This is a prospective series of liver or kidney transplant recipients with stable HIV disease. Eleven liver and 18 kidney transplant recipients were followed for a median of 3.4 years (IQR [interquartile range] 2.9-4.9). One- and 3-year liver recipients' survival was 91% and 64%, respectively; kidney recipients' survival was 94%. One- and 3-year liver graft survival was 82% and 64%, respectively; kidney graft survival was 83%. Kidney patient and graft survival were similar to the general transplant population, while liver survival was similar to the older population, based on 1999-2004 transplants in the national database. CD4+ T-cell counts and HIV RNA levels were stable; and there were two opportunistic infections (OI). The 1- and 3-year cumulative incidence (95% confidence intervals [CI]) of rejection episodes for kidney recipients was 52% (28-75%) and 70% (48-92%), respectively. Two-thirds of hepatitis C virus (HCV)-infected patients, but no patient with hepatitis B virus (HBV) infection, recurred. Good transplant and HIV-related outcomes among kidney transplant recipients, and reasonable outcomes among liver recipients suggest that transplantation is an option for selected HIV-infected patients cared for at centers with adequate expertise.

Younger age and antibody induction increase the risk for infection in pediatric renal transplantation: a NAPRTCS report.

UNLABELLED: Infections now exceed rejection as a cause of hospitalization in the first 2 years post-renal transplantation. We analyzed data from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) to determine risks for hospitalization for infection (HI), either bacterial (HBI) or viral (HVI). 3106 children transplanted between 1996 and 2002 with 2-year follow-up were analyzed. Univariate and multivariate logistic regression analyses identified factors for cause-specific hospitalization. RESULTS: 23.4% experienced HBI, 23.9% HVI; 8.9% were hospitalized for both. Children 0-1 years age at transplant had higher rates of HI (64.2%), HBI (40.3%) and HVI (43.3%) compared to >12 years (31%, 17.5% and 18.9%, p < 0.0001). In comparison to no induction, patients receiving monoclonal or polyclonal antibody were more likely to have HI (>42% vs. 34.0%), HBI (>24% vs. 21%) or HVI (>29% vs. 21%, all p < 0.003) but had equivalent graft survival (p = NS). Higher rates of HI, HBI and HVI were also seen with prophylactic antimicrobial use and with >5 transfusions pretransplant. Since antibody induction in recent era was not associated with better graft or patient survival but was associated with more HI and HVI, the need for routine antibody induction in children needs to be reassessed.

Decreased risk of renal allograft thrombosis associated with interleukin-2 receptor antagonists: a report of the NAPRTCS.

Graft thrombosis is the most common cause of first year graft failure in pediatric renal transplantation. The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database was analyzed for cases of graft failure due to thrombosis among patients transplanted from 1998 to 2004. The impact of interleukin-2 (IL-2) receptor antagonists as induction therapy was determined. There were a total of 51 graft failures due to thrombosis among the 2750 reported renal transplants (1.85%) (95% CI (1.39%, 2.41%)). This represents the most common cause of graft loss during the first year post-transplant accounting for 35% of first year losses and 18% of all graft losses. The incidence of thrombosis among patients who received IL-2 receptor antibodies was 1.07% (12/1126) compared to 2.40% (39/1624) among patients who did not (OR 0.44, 95% CI 0.23, 0.84, p = 0.014). Use of IL-2 receptor blockade was the only significant prognostic factor in a multivariate model with previously identified risk factors. Analysis of NAPRTCS data found that the use of IL-2 receptor antibodies as induction therapy is associated with a significantly decreased risk of graft failure due to thrombosis. This provocative finding requires further investigation to determine whether thrombotic failure can be decreased by this therapeutic strategy.

Posttransplant diabetes mellitus in pediatric renal transplant recipients: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

BACKGROUND: The incidence of renal post transplant diabetes mellitus (PTDM) in adults varies from 3-46%. METHODS: We did a retrospective analysis of 1365 children in The North American Pediatric Renal Transplant Cooperative Study with renal transplant (Tx) reported between January 92 and July 1997. PTDM, defined as >2 weeks of insulin therapy after Tx, developed in 36 patients. A control group of 153/1329 non-PTDM patients was selected and matched for age at Tx and primary diagnosis. RESULTS: African-Americans were overrepresented (36.1 vs. 17.6%, P=0.017) and Hispanics were underrepresented (5.6 vs. 26.1%, P=0.019) among cases. Although prednisone dose 30 days post-Tx was higher among cases (0.89 mg/kg/day) versus controls (0.71 mg/kg/day), P=0.019, cyclosporine dose was similar. No differences in prednisone or cyclosporine doses were observed at 6, 12, or 24 months post-Tx. Tacrolimus use in PTDM group was high (45%). The estimated incidence of first acute rejection at 1, 3, and 12 months was higher among cases, 0.41+/-0.08, 0.52+/-0.08, 0.61+/-0.08, compared to controls, 0.23+/-0.02, 0.37+/-0.02, and 47+/-0.02 (P=0.058). Crude graft failure rates of 13.5% (5/36) and 12.4% (19/153) were similar between the two groups, so was the calculated creatinine clearance at 12 and 24 months and post-Tx hospitalization days. CONCLUSION: PTDM occurs in <3% of children. African-Americans are at higher risk and Hispanics at lower risk for PTDM. Tacrolimus is a significant risk factor for PTDM. Children with PTDM had a higher incidence of acute rejection, but graft survival, kidney function, and hospitalization rates were similar to selected controls.

Risk factors for posttransplant lymphoproliferative disorder (PTLD) in pediatric kidney transplantation: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is an important complication of transplantation. The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database has documented 56 cases of PTLD, the largest such series to date. METHODS: We analyzed the available longitudinal and multicenter data in the NAPRTCS database to evaluate the demographic and therapeutic risk factors and the temporal trends for PTLD in children after renal transplantation. RESULTS: The overall incidence of PTLD was 1.2% of all patients or 298/100,000 posttransplantation years of follow-up. However, this incidence increased from 254/100,000 years between 1987 and 1991 to 395/100,000 years from 1992 onwards. In the same periods, the time to PTLD decreased from a median of 356 days (range 843048) to a median of 190 days (range 42-944). PTLD occurred with greater frequency in white children (P=0.003) and in cadaver donor transplants (P=0.019), but there was no significant predilection for gender, younger children (0-5 years), or primary diagnosis. No significant difference was found in the use of anti-T-cell antibodies or in doses of CsA, azathioprine, or prednisone at 1 month, 6 months, and 1 year. Between 1996 and 1997, 69 patients were initiated with tacrolimus. Eight cases of PTLD were identified in these recipients to date (prevalence rate 11.5%), compared with 46/4084 (1.1%) where cyclosporine was used (P<0.0001). CONCLUSIONS: There is a trend towards increasing incidence and earlier occurrence of PTLD in the pediatric renal transplant population. White race and cadaver donor sources are risk factors not reported before. Continued monitoring of tacrolimus immunosuppression is important.

Safety and immunogenicity of a canarypox-vectored human immunodeficiency virus Type 1 vaccine with or without gp120: a phase 2 study in higher- and lower-risk volunteers.

Live attenuated viral vectors that express human immunodeficiency virus (HIV) antigens are being developed as potential vaccines to prevent HIV infection. The first phase 2 trial with a canarypox vector (vCP205, which expresses gp120, p55, and protease) was conducted in 435 volunteers with and without gp120 boosting, to expand the safety database and to compare the immunogenicity of the vector in volunteers who were at higher risk with that in volunteers at lower risk for HIV infection. Neutralizing antibodies to the MN strain were stimulated in 94% of volunteers given vCP205 plus gp120 and in 56% of volunteers given vCP205 alone. CD8(+) cytotoxic T lymphocyte cells developed at some time point in 33% of volunteers given vCP205, with or without gp120. Phase 3 field trials with these or similar vaccines are needed, to determine whether efficacy in preventing HIV infection or in slowing disease progression among vaccinees who become infected is associated with the level and types of immune responses that were induced by the vaccines in this study.

Loss of living donor renal allograft survival advantage in children with focal segmental glomerulosclerosis.

BACKGROUND: Because of concerns of increased risk of graft loss with recurrent disease, living donor (LD) transplantation in children with focal segmental glomerulosclerosis (FSGS) has been controversial. METHODS: The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database from January 1987 to January 2000 was examined to determine differences in demographics, treatment, and outcomes in children with FSGS compared with other renal diseases. RESULTS: Data on 6484 children, 752 (11.6%) with FSGS, demonstrated that FSGS patients were more likely to be older and black, and were less likely to receive either pre-emptive or LD transplant (P < 0.001). No differences existed in human lymphocyte antigen (HLA) matching or immunosuppression regimens. Acute tubular necrosis occurred in more FSGS patients following LD (11.8 vs. 4.6%) or cadaveric (CD; 27.9 vs. 16.3%) transplants (P < 0.001). Graft survival was worse for LD FSGS patients (5 years 69%) compared with no FSGS (82%, P < 0.001) and was not significantly different than CD graft survival in the FSGS (60%) and No FSGS groups (67%). The LD to CD ratios of relative risk of graft failure were higher in FSGS patients (test for interaction, P = 0.01). Recurrence of original disease was the only cause of graft failure that differed between groups (P < 0.001). A greater percentage of LD FSGS graft failures was attributed to recurrence (P = 0.06). CONCLUSIONS: The impact of FSGS on graft survival in children is greatest in LD transplants, resulting in loss of expected LD graft survival advantage. The rationale for LD grafts in children with FSGS should be based on factors other than better outcomes typically associated with LD transplantation.

Rejection profile of recent pediatric renal transplant recipients compared with historical controls: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

Historically, higher acute rejection rates, earlier first rejection, and an inability to reverse the rejection characterize pediatric renal transplantation. In recent years, short-term (1-year) graft survival of pediatric renal transplants has steadily improved. To test the hypothesis that these improvements were mediated by changes in acute rejection, we considered the rejection profile of patients who received a renal allograft between 1987 and 1989 (cohort A) and compared it with recipients transplanted between 1997 and 1999 (Cohort B). Cohort A comprised 1469 transplants and cohort B comprised 1189 transplants. Restricting the data to the first year of follow-up, rejection ratios were 1.6 and 0.7, respectively (p < 0.001). Sixty per cent of the later cohort (B) were rejection free at 1 year, compared with 29% for the earlier cohort (A) (p < 0.001). Controlling for donor source, the rejection reversal rate for the later cohort was significantly better than that of the early cohort (p < 0.001). Cumulative distribution of times to first rejection was significantly better for cohort B (p < 0.001). One-year graft survival for cohort B at 94% was significantly better than 80% for cohort A (p < 0.001). We conclude that the improved short-term graft survival is mediated by improvements in the rejection profile in more recently transplanted patients and that this may translate into a better half-life for pediatric renal transplant recipients who received an allograft in the years 1997-99.

A phase II study of two HIV type 1 envelope vaccines, comparing their immunogenicity in populations at risk for acquiring HIV type 1 infection. AIDS Vaccine Evaluation Group.

Several immunogens induce HIV-specific neutralization and in vitro lymphoproliferation in adults at low HIV-1 risk, but responses in persons at high HIV-1 risk are not known. We performed a multicenter, double-blinded, adjuvant-controlled trial with two gp120 vaccines in 296 HIV-1-uninfected volunteers, including 176 reporting higher HIV-1 risk activities. The immunogens were remarkably well tolerated. After three immunizations, 210 of 241 vaccinees (87%) developed neutralizing antibodies, which persisted in 59% after 2 years. The injection drug users receiving SF-2/gp120 had decreased antibody responses relative to the lower risk groups. Envelope-specific lymphoproliferation peaked after two immunizations, and 54% of vaccinees mounted a DTH reaction to gp120 after 4 years. In summary, these immunogens have low adverse reactogenicity and induce durable antibody and T cell responses to the prototype strains. Unexpected differences in antibody responses among diverse HIV-1 risk strata lend support to the conduct of expanded phase II trials in populations other than low-risk volunteers.

Improved graft survival after renal transplantation in the United States, 1988 to 1996.

BACKGROUND: The introduction of cyclosporine has resulted in improvement in the short-term outcome of renal transplantation, but its effect on the long-term survival of kidney transplants is not known. METHODS: We analyzed the influence of demographic characteristics (age, sex, and race), transplant-related variables (living or cadaveric donor, panel-reactive antibody titer, extent of HLA matching, and cold-ischemia time), and post-transplantation variables (presence or absence of acute rejection, delayed graft function, and therapy with mycophenolate mofetil and tacrolimus) on graft survival for all 93,934 renal transplantations performed in the United States between 1988 and 1996. A regression analysis adjusted for these variables was used to estimate the risk of graft failure within the first year and more than one year after transplantation. RESULTS: From 1988 to 1996, the one-year survival rate for grafts from living donors increased from 88.8 to 93.9 percent, and the rate for cadaveric grafts increased from 75.7 to 87.7 percent. The half-life for grafts from living donors increased steadily from 12.7 to 21.6 years, and that for cadaveric grafts increased from 7.9 to 13.8 years. After censoring of data for patients who died with functioning grafts, the half-life for grafts from living donors increased from 16.9 years to 35.9 years, and that for cadaveric grafts increased from 11.0 years to 19.5 years. The average yearly reduction in the relative hazard of graft failure after one year was 4.2 percent for all recipients (P<0.001), 0.4 percent for those who had acute rejection (P=0.57), and 6.3 percent for those who did not have acute rejection (P<0.001). CONCLUSIONS: Since 1988, there has been a substantial increase in short-term and long-term survival of kidney grafts from both living and cadaveric donors.

Immunization with recombinant canarypox vectors expressing membrane-anchored glycoprotein 120 followed by glycoprotein 160 boosting fails to generate antibodies that neutralize R5 primary isolates of human immunodeficiency virus type 1.

Antibodies generated by candidate HIV-1 vaccines in a phase I clinical trial were assessed for neutralizing activity with a panel of eight well-characterized, genetically diverse clade B primary isolates having an R5 phenotype. The vaccines consisted of one of three different recombinant canarypox vectors expressing membrane-anchored HIV-1(MN)gp120 (ALVAC vCP205, vCP1433, and vCP1452) followed by boosting with a soluble gp160 hybrid consisting of MNgp120 and the majority of gp41 from strain IIIB. Serum samples from a subset of volunteers in each arm of the trial, containing moderate to high titers of neutralizing antibodies to HIV-1 MN, were analyzed. Competition assays with peptides revealed that the majority of neutralizing activity was specific for the MN-V3 loop. Despite MN-specific neutralization titers that sometimes exceeded 1:500, no neutralization of primary isolates was detected and, in some cases, mild infection enhancement was observed. In addition, little or no neutralization of the HIV-1 IIIB heterologous T cell line-adapted strain of virus was detected. These results reinforce the notion that monovalent HIV-1 ENV is a poor immunogen for generating cross-reactive neutralizing antibodies.

Center volume effects in pediatric renal transplantation. A report of the North American Pediatric Renal Transplant Cooperative Study.

An inverse relationship between mortality and center volume has been established for several surgical procedures. Given the distinctiveness of pediatric renal transplantation and the large variation in center volume, investigation for relationships between center volume and graft outcome was pursued using the North American Pediatric Transplant Cooperative Study database. Center volume groups were based on the total number of pediatric transplants reported from 1987 to 1995. Centers reporting > 100, 51-100, or < or = 50 transplants were grouped as high- (n=11), moderate- (n=28), or low-volume (n=65), respectively. Differences between groups included increasing rates of cadaver donor graft thrombosis (2.4%, 4.3%, and 5.7%, P<0.01) and acute tubular necrosis (ATN) (10.2%, 11.5%, and 14.0%, P<0.01) with decreasing center volume. Treatment differences included a higher rate of induction with an anti-T-cell antibody preparation in the larger-volume groups, 60.2%, 51.8%, and 39.2% (P<0.001). Decreasing graft survival for decreasing center size groups was noted at 3 months post transplant, 90.4%, 90.2%, and 88.4%. These differences were significant only with the exclusion of anti-T-cell induction from the proportional hazards model (relative risk=0.81 and =0.70 for the moderate- and high-volume groups, P<0.02). Superior graft survival in the high-volume centers noted at 3 months post transplant appears predominantly the result of lower rates of cadaver donor graft thrombosis and ATN. Analysis points to the need for low-volume centers to identify risk factors influencing these outcomes.

The 1997 Annual Renal Transplantation in Children Report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

This report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS), covering the years 1987-96 (January 15, 1997), analyzed data on 4898 patients who received 5362 transplants. Over the 10 yr of the study, 21.3% of the patients were under the age of 6 yr. Of the disorders that lead to end-stage renal disease (ESRD), structural and developmental anomalies of aplasia, dysplasia, and obstructive uropathy accounted for over 1500 patients. Despite the potential therapies for focal segmental glomerulosclerosis (FSGS), there has been little change in its incidence and this lesion continues to be the most common cause of renal failure and transplantation among acquired diseases. Eighty-nine per cent of patients with a functioning graft continue to receive cyclosporin A (CsA) 5 yr post-transplantation, and 84% of patients continue to receive azathioprine (AZA), whereas 26% of patients receive alternate-day steroid therapy at 4 yr post-transplant. Thirty-seven per cent of the living donor (LD) recipients and 47% of cadaver donor (CD) recipients were treated with the polyclonal T-cell antibody ATG/ALG for induction, and the monoclonal T-cell antibody, OKT3, was utilized for induction in 12% of LD patients and in 19% of CD patients. Twenty-five per cent of the 5362 transplants (1333) have failed over the 10-yr period. Graft survival is 90% at 1 yr and 74% at 6 yr for LD kidneys, and is 80% at 1 yr and 58% at 6 yr for CD patients. The most common cause for graft failure (30%) is chronic rejection. For recipients of LD grafts, relative risk (RR) factors for graft survival are African-American race (RR = 2.1, p < 0.001) and greater than five prior transfusions (RR = 1.6, p < 0.001). Prophylactic anti-T-cell antibody reduces the risk of graft failure (RR = 0.76, p = 0.009). For recipients of cadaver kidneys, risk factors are: recipient age < 2 yr (RR = 2, p < 0.001), donor age < 6 yr (RR = 1.3, p = 0.005), and absence of induction T-cell antibody (RR = 1.31, p < 0.001).