Abstract. Reported are the reduction of anti-HLA antibody levels and improvement of transplant rates by intravenous immunoglobulin (IVIG) in a randomized, double-blind, placebo-controlled clinical trial. Between 1997 and 2000, a total of 101 adult patients with ESRD who were highly sensitized to HLA antigens (panel reactive antibody [PRA] Ն50% monthly for 3 mo) enrolled onto an NIH-sponsored trial (IG02). Patients received IVIG or placebo. Subjects received IVIG 2 g/kg monthly for 4 mo or an equivalent volume of placebo with additional infusions at 12 and 24 mo after entry if not transplanted. If transplanted, additional infusions were given monthly for 4 mo. Baseline PRA levels were similar in both groups. However, IVIG significantly reduced PRA levels in study subjects compared with placebo. Sixteen IVIG patients (35%) and eight placebo patients (17%) were transplanted. Rejection episodes occurred in 9 of 17 IVIG and 1 of 10 placebo subjects. Seven graft failures occurred (four IVIG, three placebo) among adherent patients with similar 2-yr graft survival rates (80% IVIG, 75% placebo). With a median follow-up of 2 yr after transplant, the viable transplants functioned normally with a mean Ϯ SEM serum creatinine of 1.68 Ϯ 0.28 for IVIG versus 1.28 Ϯ 0.13 mg/dl for placebo. Adverse events rates were similar in both groups. We conclude that IVIG is better than placebo in reducing anti-HLA antibody levels and improving transplantation rates in highly sensitized patients with ESRD. Transplant rates for highly sensitized patients with ESRD awaiting kidney transplants are improved with IVIG therapy.Kidney transplantation is the preferred treatment for patients with ESRD. The benefits are evidenced by prolonged survival and improved quality of life for both children and adults. Despite these well documented benefits, transplant frequency remains lower than desirable as a result of limited organ availability (1,2). In patients with high levels of preformed anti-HLA antibodies (high panel reactive antibody [PRA]; highly sensitized), transplant rates are very low because of the additional immunologic barrier. Approximately 30% of patients on the waiting list are classified as sensitized, meaning they have peak PRA levels Ͼ20%, with about half of these having peak PRA levels Ͼ80%. These antibodies result from exposure to nonself HLA antigens; usually from previous transplants, blood transfusions, or pregnancy. Accordingly, women with ESRD are disproportionately sensitized compared with men.Patel and Terasaki (3) established in 1969 that the presence of anti-donor IgG antibody (positive crossmatch) was a contraindication for kidney transplantation. Accordingly, the higher the PRA, the more difficult it becomes to find an immunologically compatible match. Transplant rates are lower

MATERIALS AND METHODSImmunogens and Immunization Schedules. 10-to 12-week old female BALB/cAnN mice were injected with purified myelomaproteins 315 or 460, which were isolated by subjection of the proteins to mild reduction and alkylation (in this work with iodoacetic acid) (2, 3). Proteins 315 and 460 purified in this manner (820w,, = 6.5) have about eight carboxymethyl groups per molecule (150,000 daltons), one on the C-terminal or penultimate cysteine of the light chain and 3-4 on the heavy chain (4). Both purified proteins had intact ligandbinding sites, as shown by specific quenching of their tryptoAbbreviation: TD5o, number of cells required to produce tumors in 50% of control (untreated) animals; Dnp, 2,4-dinitrophenyl.

Limited data exist on the safety and efficacy of bariatric surgery (BS) in patients with kidney failure. We examined Medicare billing claims within USRDS registry data (1991–2004) to identify BS cases among renal allograft candidates and recipients. Of 188 cases, 72 were performed pre-listing, 29 on the waitlist, and 87 post-transplant. Roux-en-Y gastric bypass was the most common procedure. Thirty-day mortality after BS performed on the waitlist and post-transplant was 3.5%, and one transplant recipient lost their graft within 30 days after BS. BMI data were available for a subset and suggested median excess body weight loss of 31%-61%. Comparison to published clinical trials of BS in populations without kidney disease indicates comparable weight loss but higher post-BS mortality in the USRDS sample. Given the substantial contributions of obesity to excess morbidity and mortality, BS warrants prospective study as a strategy for improving outcomes before and after kidney transplantation.

Human antibody Fab fragments that bind to hepatitis B surface antigen (HBsAg) were generated by using a recombinant phage surface-display expression system. Characterization ofHBsAg-specific Fab fragments isolated from two vaccinated individuals reveals diversity in specificity of antigen binding and in the sequences of the complementaritydetermining region. The sequence results show examples of human light-chain promiscuity that result in fine specificity changes and a strong relationship to a human germ-line gene. This application illustrates further that this technique is a powerful tool to isolate distinct human antibodies against immunogenic viral targets.The expression of diverse human monoclonal antibodies through the use of combinatorial systems has potential for the identification and development of these reagents as therapeutics. Use of a modified bacteriophage A genome for bacterial expression of both human and mouse antibodies has been described (1-6). The essence of this approach is that a repertoire of antibodies can be re-created from random pairings of cloned heavy-and light-chain genes.Recently, improvements to the expression of combinatorial antibody libraries were developed to allow for antigenspecific screening of larger libraries (7,8). These improvements are based on reports demonstrating the expression of peptides and proteins on the surface of filamentous phage (9-18). The combinatorial antibody approach directs the expression of recombinant antibody Fab fragments to the surface of filamentous phage through the selection of a phagemid that coexpresses the combinations of heavy-and light-chain genes. Heavy-chain expression is linked to the phage coat protein gene III membrane anchorage domain, and the resulting fusion protein becomes anchored into the periplasmic space. Expression of the light chain from the plasmid DNA as a secreted protein permits Fab assembly within the periplasmic space. After helper phage infection, this antibody Fab then becomes incorporated into a phage by replacement of the wild-type gene III protein, and the Fab is displayed on the phage surface.The main advantage of the phage surface technology is the ability to sort large combinatorial libraries by a powerful enrichment and selection process. The selection process makes the combinatorial antibody technology attractive for the isolation of specific high-affinity human antibodies and for antibody isolation from individuals with low serum titers to the desired antigen.To examine the application of the phage surface-display technology to a viral system, we chose to generate and characterize human antibodiest to hepatitis B surface antigen (HBsAg). The availability of vaccines, purified antigen, and murine antibodies for epitope mapping makes the hepatitis target an ideal model system to study the immune response to a viral antigen. MATERIALS AND METHODSImmunization and RNA Preparation. A human volunteer was immunized with the hepatitis B virus recombinant vaccine Recombivax (Merck). On day 7 following the se...

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