Paul W. Nelson

Evolving Use Of Okt3 Monoclonal Antibody For Treatment Of Renal Allograft Rejection

OKT3, a monoclonal antibody reactive with a surface glycoprotein present on all postthymic T cells, was used to treat the initial acute episode of rejection in 30 recipients of cadaveric donor renal allografts. The first 16 patients received 1–5 mg daily for a period of 10–21 days during which the azathioprine and prednisone dosages were sharply reduced. Circulating T cells were eliminated within minutes after the first OKT3 infusion. T cells reactive with OKT3 remained depressed throughout the period of treatment, although a significant number of cells reactive with other T cell subset reagents became detectable after several days of OKT3 treatment. In all instances, the established rejection episode was reversed in 2–8 days without the addition of other immunosuppressive measures. Recurrent rejection occurred in 12 of 16 patients, but with further conventional immunosuppression, 50% of the renal allografts remain functional 20–44 months after transplantation. Fever, chills, and, in some instances, dyspnea following the first dose of OKT3 were the only side-effects observed. Most patients developed antiidiotypic or antimouse immunoglobulin antibodies without apparent clinical sequelae. In the subsequent 14 patients, modifications in the protocol included a steroid bolus prior to the first OKT3 infusion, limitation of therapy to 10 days, resumption of maintenance levels of azathioprine and prednisone prior to discontinuing OKT3, and addition of 3 i.v. doses of cyclophosphamide at the termination of treatment. Respiratory symptoms after the first infusion of the reagent have been eliminated. Antibody responses to OKT3 have been reduced, occurring in 38% as compared with 73% of patients treated previously. Recurrent rejection episodes observed in 8 of 14 patients have been reversible in all but one case. Allograft survival is 86% at 6–17 months posttransplantation. In the entire series of 30 OKT3-treated patients, only 4 grafts (13%) have been lost because of recurrent episodes of rejection.

Ten-year experience in transplantation of A2 kidneys into B and O recipients

BACKGROUND This article summarizes our 10-year multicenter experience with transplantation of 50 blood group A2 and A2B kidneys into B and O patients. METHODS Since 1986, we have transplanted kidneys from 46 cadaver donors and 4 living donors who were blood group A2 (47 donors) or A2B (3 donors) into 19 B and 31 O patients. In 1991, we began allocating these kidneys preferentially to B and O recipients who were selected based on a history of low (< or =4) anti-A IgG isoagglutinin titers. Immunosuppression was no different from that used in ABO-compatible grafts. RESULTS The 1-month function rate before thus selecting the patients was 68% (19/28), but is now 94% (17/18). Two-year cadaver-donor graft survival with this selection method is 94%, compared with 88% for 640 concurrent and consecutive ABO-compatible transplants (log-rank, 0.15). All four living-related transplants are still functioning, with a mean follow-up of 71 months. Since we began allocating A2 kidneys preferentially to B and O recipients, the percentage of the B patients who received A2 or A2B kidneys has increased from 29% (8/28) to 55% (10/18). CONCLUSIONS Transplantation of A2 or A2B kidneys into B and O patients is clinically equivalent to that of ABO-compatible transplantation when recipients are selected by low pretransplant anti-A titer histories. This approach increases access of blood group B recipients to kidneys.

Long-term graft survival is improved in cadaveric renal retransplantation by flow cytometric crossmatching.

BACKGROUND Cadaveric renal retransplantation is associated with a higher risk of early graft failure than primary grafts. A large proportion of those graft losses is likely attributable to donor-directed HLA class I antibodies, detectable by flow cytometry cross-matching but not by conventional crossmatching techniques. METHODS Long-term graft survival in a group of 106 recipients of consecutive cadaveric renal regrafts between 1990 and 1997, in whom a negative flow T-cell IgG crossmatch was required for transplantation, was compared with two other groups of cadaveric transplant recipients. The first group consisted of 174 cadaveric regrafts transplanted between 1985 and 1995 using only a negative anti-human globulin (AHG) T-cell IgG crossmatch. The second group was primary cadaveric transplants done concurrently with the flow group (1990 to 1997) using only the AHG T-cell IgG crossmatch. RESULTS The long-term (7 year) graft survival rate of flow crossmatch-selected regraft recipients (68%; n= 106) was significantly improved over that of regraft recipients who were selected for transplantation by only the AHG crossmatch technique (45%; n=174; log-rank=0.001; censored for patients dying with a functioning graft). Graft outcome for the flow cross-matched regraft recipients was not significantly different from that of primary cadaveric patients (72%; n=889; log-rank=0.2; censored for patients dying with a functioning graft). Finally, a positive B-cell IgG flow cytometric crossmatch had no influence on long-term regraft outcome. CONCLUSIONS The use of the flow T-cell IgG cross-match as the exclusion criterion for cadaveric renal retransplantation yields an improved long-term graft outcome over that obtained when only the AHG cross-match is used and has improved survival of regraft recipients to the level of our primary cadaveric renal transplant population.

Current experience with renal transplantation across the ABO barrier.

Solid organ transplantation has traditionally been governed by the rules of blood group compatibility. Thus, it has been demonstrated that crossing the ABO blood group barrier generally results in hyperacute rejection. However, the A2 subtype of the blood group A is a weaker antigen. Under certain circumstances, organs from donors with blood group A2 can be transplanted across the ABO blood group barrier into recipients of O or B blood type. Since 1986, 33 patients including 24 blood group O and 9 blood group B patients received A2 (30) or A2B (3) donor kidneys. Both cadaver donor (31) and living-related grafts (2) have been undertaken. The mean follow-up since transplantation for the 21 patients with functioning grafts is 36 months, with a 67.2% current graft survival. Immunosuppression for these transplants consisted of azathioprine, prednisone, and cyclosporine, often in combination with prophylactic OKT3 or antilymphocyte globulin as protocol dictated. Special immunosuppressive protocols such as splenectomy or plasmapheresis were not used. The serum of the potential recipient was analyzed for immunoglobulin G (IgG) and immunoglobulin M (IgM) forms of antibody against A1 and A2 red blood cells. There is a strong correlation between a low (less than or equal to 1:8) anti-A1 IgG titer and both early and long-term graft function. Recipients with an IgG titer greater than 1:8 in the pretransplant serum had a much higher incidence of early graft failure. We no longer recommend transplantation of A2 kidneys into O or B recipients with a pretransplant titer of greater than 1:8 but found that recipients with low titers have graft function rates essentially equal to those of ABO-compatible patients. Patients with blood group B have, over time, lower anti-A IgG titers than do blood group O patients. In addition, the graft survival among blood group B patients is 89% compared with 58% among group O recipients. This may be due to the generally low titers found in blood group B recipients. Since instituting a policy in 1988 of not transplanting the kidney when the anti-A IgG titer is greater than 1:8, the survival in O patients is 88%. We recommend the screening of all organ donors with blood group A for the A2 subgroup and believe that transplantation can be safely and successfully performed in certain patients with blood group O or B.(ABSTRACT TRUNCATED AT 400 WORDS)

The presence of in-house attending trauma surgeons does not improve management or outcome of critically injured patients.

BACKGROUND The presence of a surgeon at the initial assessment and care of the trauma patient has been the focal point of trauma center designation. However, for Level I verification, the American College of Surgeons Committee on Trauma currently does not require the presence of an attending trauma surgeon in the hospital (IH), provided senior surgical residents are immediately available. Likewise, the state of Missouri does not mandate an IH presence of the attending trauma surgeon but requires senior (postgraduate year 4 or 5) level surgical residents to immediately respond, with a 20-minute response time mandated for the attending surgeon if IH or out of the hospital (OH). Nevertheless, some claim that IH coverage by attending surgeons provides better care for seriously injured patients. METHODS This retrospective study assessed patient care parameters over the past 10 years on critically injured patients to detect any difference in outcome whether the surgeon was IH or OH at the time of the trauma team activation (cardiopulmonary instability, Glasgow Coma Scale [GCS] score < 9, penetrating truncal injury). Patients were subcategorized into blunt/penetrating, shock (systolic blood pressure < 90 mm Hg) on arrival, GCS score < 9, Injury Severity Score (ISS) > 15, or ISS > 25. Response was examined from 8 am to 6 pm weekdays (IH) or 6 pm to 8 am weekdays and all weekends (OH). Patient care parameters examined were mortality, complications, time in the emergency department, time to the operating room, time to computed tomographic scanning, intensive care unit length of stay (LOS), and hospital LOS. RESULTS For all patients (n = 766), there was no significant difference in any parameters except intensive care unit LOS (IH, 4.90 +/- 7.96 days; OH, 3.58 +/- 7.69 days; p < 0.05). For blunt trauma (n = 369), emergency department time was shorter (99.71 +/- 88.26 minutes vs. 126.51 +/- 96.68 minutes, p < 0.01) and hospital LOS was shorter (8.04 +/- 1.02 days vs. 11.08 +/- 1.15 days, p < 0.05) for OH response. For penetrating trauma (n = 377), shock (n = 187), GCS score < 9 (n = 248), ISS > 15 (n = 363), and ISS > 25 (n = 230), there were no statistically significant differences in any patient care parameter between IH and OH response. For those in most need of urgent operation-penetrating injuries and shock-there were no differences in time to operating room or mortality for OH or IH response. CONCLUSION As long as initial assessment and care is provided by senior level IH surgical residents and as long as the attending surgeon responds in a defined period of time (if OH) to guide critical decision-making, the IH presence of an attending surgeon has not been shown in this retrospective study to improve care of the critically injured patient.

Cold ischemia time: An independent predictor of increased HLA class I antibody production after rejection of a primary cadaveric renal allograft

Background. Cadaveric kidneys experiencing longer cold ischemia time (CIT) are associated with higher levels of delayed graft function, acute rejection, and early graft loss. One mechanism to explain these results is that ischemia/reperfusion (I/R) injury makes the allograft more immunogenic by upregulating molecules involved in the immune response (e.g., HLA Class I/II). Methods. We evaluated the influence of CIT on the production of HLA Class I antibody level, measured by an antihuman globulin panel reactive antibody (AHG PRA) level, in 90 unsensitized recipients of primary cadaveric renal transplants (from a total of 1442 between 1985 and 1997) who rejected their kidneys. Results. By multivariate analysis, a CIT of 15 hr or more (vs.<15 hr) independently increased the risk of the AHG Class I PRA level being ≥20% after unsensitized patients rejected their first kidneys (relative risk=3.57; 95% confidence interval=1.26 to 10.14;P =0.01), despite the same degree of Class I/II mismatch between the two CIT groups. The overall mean peak PRA level after primary kidney rejection was significantly lower for the CIT<15 hr group (25.9%±33.9; n=24) compared with the CIT≥15 hr group (46.3%±36.5; n=66) (P <0.001). Conclusion. Longer CIT induces a humorally more immunogenic kidney.

Successful transplantation of blood group A2 kidneys into non-A recipients

The ABO subgroup A2 has been reported to be less reactive with the anti-A1 antibody naturally occurring in the serum of group O and B recipients and to occur in approximately 20% of group A individuals. Between March 1986 and February 1987, the Midwest Organ Bank (MOB) in Kansas City, screened all group A renal donors for the A2 subgroup. A total of 190 cadaver-donor kidneys were retrieved during this time, of which 68 were subgroup A1 and 16 were subgroup A2 (incidence of A2 = 19% of As and 8.5% of all donors). Of the subgroup A2 kidneys, 13 were transplanted into 9 group O and 4 group B recipients. One group O recipient received an HLA-identical A2 living-related graft. Recipients were not preselected or modified by splenectomy, plasmapheresis, or other means, and were treated with cyclosporine, steroids—and, in most cases, azathioprine, after transplantation. There was one hyperacute rejection and there were 5 acute cellular rejection episodes, 3 of which were reversed. One additional patient died at 2.5 months with a functioning graft. Including the successful living-related graft, 10 of 14 patients (71%) have functioning grafts, with a follow-up of 5 to 14 months, and a mean creatinine of 1.7 mg/dl. We find that the A2 subgroup represents a small but important minority of A donors, and that transplantation into non-A recipients can generally, but not universally, be safely accomplished. We recommend the screening of A donors for the A2 subgroup in both the cadaver-donor and living-related groups, and suggest that the utilization of A2 donors in non-A patients may contribute to the transplantation of group O and highly sensitized patients—and, in some cases, improve the degree of HLA matching.

HLA Points Assigned in Cadaveric Kidney Allocation Should Be Revisited: An Analysis of HLA Class II Molecularly Typed Patients and Donors

The points now assigned for the quality of HLA match have received significant scrutiny to be modified in an effort to help reduce disparity in access to kidneys of minority groups, and since differences in graft survival between groups of patients in each of the HLA matched groups is less now than in the past.

Detection of HLA IgG antibodies by two enzyme-linked immunoassays, solubilized HLA class I and PRA-STAT : comparison with the AHG PRA

HLA class I-directed IgG antibodies have traditionally been detected with a complement-dependent lymphocytotoxicity (CDL) technique. We have evaluated two solid-phase enzyme-linked immunoassays (EIA) and compared them with the CDL antihuman globulin (AHG) dithiothreitol-treated (DTT) PRA in their ability to discriminate between the presence or absence of HLA class I-directed IgG antibodies in serum from patients awaiting transplantation. The EIA were: (1) an EIA that uses solubilized HLA class I antigens (sHLA-I) isolated from a 240-member platelet donor pool, and (2) the PRA-STAT ELISA kit. For the first comparison, we used 691 serum samples from 272 patients taken before they had been transplanted. The data show a significant (P < 0.0001) linear correlation (r = 0.77 between the AHG DTT PRA and the sHLA EIA. They also demonstrate that the mean sHLA-I EIA ratio significantly increases (P < 0.01) above background levels with each stepwise increase in AHG DTT PRA level. Discordant results were 1.0% (7/691) for sHLA-I EIA+ PRA- and 6.3% (44/691) for PRA+ sHLA-I EIA-. However, a lower correlation was noted between the AHG DTT PRA and the PRA-STAT (Nextran) PRA results (n = 230; r = 0.42). The sHLA-I EIA is able to determine whether or not HLA Class I IgG antibodies are present in serum from transplant candidates and is an appropriate adjunct to the traditional CDL PRA assay, whereas the PRA-STAT is not.

Anaphylactic reaction and cardiopulmonary arrest following intravenous cyclosporine

Cyclosporine, a new immunosuppressive agent useful in recipients of a variety of organ transplants, has been associated with a number of adverse effects, most notably nephrotoxicity. This report describes a woman about to undergo liver transplantation in whom intravenous administration of cyclosporine was associated with an apparent anaphylactic reaction resulting in cardiopulmonary arrest. Similar reactions have thus far not been reported after oral administration of cyclosporine. Intravenous cyclosporine must be administered under close supervision and should be avoided in any patients with a history of prior allergic reactions to the drug or to a component of its intravenous formulation.