Variation in Cost and Quality in Kidney Transplantation.

BACKGROUND: Bending the cost curve in medical expenses is a high national priority. The relationship between cost and kidney allograft failure has not been fully investigated in the United States. METHODS: Using Medicare claims from the United States Renal Data System, we determined costs for all adults with Medicare coverage who underwent kidney transplant January 1, 2007, to June 30, 2009. We compared relative cost (observed/expected payment) for year 1 after transplantation for all transplant centers, adjusting for recipient, donor, and transplant characteristics, region, and local wage index. Using program-specific reports from the Scientific Registry of Transplant Recipients, we correlated relative cost with observed/expected allograft failure between centers, excluding small centers. RESULTS: Among 19,603 transplants at 166 centers, mean observed cost per patient per center was $65,366 (interquartile range, $55,094-$71,624). Mean relative cost was 0.99 (± 0.20); mean observed/expected allograft failure was 1.03 (± 0.46). Overall, there was no correlation between relative cost and observed/expected allograft failure (r = 0.096, P = 0.22). Comparing centers with higher than expected costs and allograft failure rates (lower performing) and centers with lower than expected costs and failure rates (higher-performing) showed differences in donor and recipient characteristics. As these characteristics were accounted for in the adjusted cost and allograft failure models, they are unlikely to explain the differences between higher- and lower-performing centers. CONCLUSIONS: Further investigations are needed to determine specific cost-effective practices of higher- and lower-performing centers to reduce costs and incidence of allograft failure.

Natural killer cell HLA-C epitopes and killer cell immunoglobulin-like receptors both influence outcome of mismatched unrelated donor bone marrow transplants.

Matching of donor and recipient for the class I human leukocyte antigen-C (HLA-C)-encoded natural killer (NK) epitopes has been reported to influence stem-cell (SC) graft outcome, but a consistent picture has not yet emerged. We have analyzed transplant outcome in 104 unrelated SC grafts in relation to NK epitope (C1 and C2) matching and donor killer cell immunoglobulin-like receptor (KIR) genotype. NK epitope mismatching in the rejection direction was strongly associated with an increased probability of rejection subsequent to engraftment. The prevalence of grades III-IV acute graft-vs-host disease (GVHD) was significantly higher and occurred significantly earlier when there was NK epitope mismatching in the GVH direction. Higher transplant-related mortality and lower disease-free survival rates were associated with epitope mismatching regardless of the mismatch direction. A greater number of KIR receptors, both activating and inhibitory, in the donor protected against grades III-IV GVHD and improved survival.

The beneficial role of inhibitory KIR genes of HLA class I NK epitopes in haploidentically mismatched stem cell allografts may be masked by residual donor-alloreactive T cells causing GVHD.

HLA allele mismatches will provoke T-cell alloreactivity after allogeneic stem cell transplantation. As donors and recipients are usually HLA matched, the public HLA epitopes that are recognized by natural killer (NK) cells (NK epitopes) are rarely mismatched, and therefore there is rarely potential for NK alloreactivity arising from the absence of ligands for inhibitory killer immunoglobulin-like receptors (KIR). Transplants using related donors sharing only one haplotype (haploidentical donors) represent a setting in which NK epitopes are often mismatched, thus resulting in the potential for NK alloreactivity. We have analyzed engraftment, acute graft vs host disease (GVHD), leukemia relapse, and survival in 62 haploidentical transplants in relationship with potential NK alloreactivity, inhibitory, and activating KIR genes of class I HLA NK epitopes. Potential NK alloreactivity in the rejection direction was not associated with any outcome variable. Potential NK alloreactivity in the GVHD direction was associated with an increased incidence of severe GVHD and poorer patient survival but not with non-engraftment nor leukemia relapse. A higher number of activating KIR receptors in the genome of the donor was associated with a higher prevalence of GVHD. These results suggest that lack of extensive T-cell depletion in haploidentical transplantation is associated with high GVHD rates and diminishes the benefits of NK-cell alloreactivity.

Regular radon activity concentration and effective dose measurements inside the great pyramid with passive nuclear track detectors.

Radon activity concentrations and equilibrium factors inside the great pyramid of "Cheops" were measured with passive nuclear track detectors. The variation of these concentrations in location was investigated. Seasonal variation of radon activity concentrations with winter maximum and summer minimum were observed inside the pyramid. The 1-y average radon activity concentration ranged from a minimum of 20 to a maximum of 170 Bq m(-3). Results show that the yearly average equilibrium factor between radon and its progeny was assessed as 0.16 and 0.36 inside the pyramid and near entrance, respectively. Moreover, the estimated annual effective dose was 0.05 mSv to tour guides and varied from 0.19 to 0.36 mSv for the pyramid guards; for visitors the average effective dose was 0.15 microSv per visit. These are lower than the 3-10 mSv y(-1) dose limit recommend by ICRP 65.

Acute profound thrombocytopenia following abciximab therapy.

OBJECTIVE: To report a case of acute, profound thrombocytopenia (APT), defined as an abrupt drop in platelet count to <20,000/mm3 that occurred within 24 hours of administration of an abciximab bolus, to summarize other abciximab-associated APT cases reported in the literature, to review the postulated mechanisms behind this reaction, and to emphasize the importance of periodically monitoring platelet counts after initiating abciximab therapy. DATA SOURCES: MEDLINE and Index Medicus searches restricted to English-language literature from 1993 through June 1999 were conducted. MeSH headings included abciximab, ReoPro, thrombocytopenia, and glycoprotein IIb-IIIa (GP IIb-IIIa) inhibitors. References of the articles obtained were also reviewed. DATA EXTRACTION: Search and evaluation were focused on published case reports and reviews of abciximab-induced APT, as well as the incidence of thrombocytopenia from the drug compared with that from other GP IIb-IIIa inhibitors. DATA SYNTHESIS: Platelet aggregation has been identified as the structural basis for coronary thrombosis. This may lead to ischemic complications during acute coronary syndromes or following coronary intervention procedures. The use of GP IIb-IIIa inhibitors such as abciximab as antiplatelet agents has been effective in reducing these ischemic complications. We summarize 15 published cases of abciximab-associated APT gathered from data on 2,482 patients treated with the drug. Prior to suspecting abciximab, other potential causes of thrombocytopenia should be evaluated. It is important to monitor the platelet count at baseline, two hours after initiating abciximab, and 24 hours after initiation of therapy or prior to discharge, whichever comes first, to identify patients at risk for developing APT. If APT occurs and is left untreated, it can produce excessive hemorrhage and ischemia, potentially leading to death. Platelet transfusions have been more effective than immunoglobulin in the management of APT. CONCLUSIONS: Abciximab-induced APT has a low incidence of occurrence. If it does develop and is not recognized or treated promptly, it can lead to serious hemorrhagic complications. Consequently, monitoring the platelet count two hours after initiation of the infusion is essential. If APT develops, abciximab should be discontinued and a platelet transfusion should be considered.

Alloreactivity of umbilical cord blood mononuclear cells: specific hyporesponse to noninherited maternal antigens.

Earlier studies noted that patients who underwent cord blood (CB) transplantation had a lower incidence of graft-versus-host disease (GVHD) than those who underwent bone marrow transplantation (BMT). The premise that the immune reactivity of CB mononuclear cells (CB-MNC) to HLA mismatched combinations and to noninherited maternal antigens (NIMA) may be one of the factors involved in this phenomenon is still debatable. In this study we have attempted to evaluate the alloresponse and alloreactivity induced by CB-MNC by means of the standard mixed lymphocyte reaction test (SMLR) and the more sensitive, modified mixed lymphocyte reaction test (MMLR). Both techniques were used to test CB-MNC (n = 28) against HLA class II mismatched MNC from mothers (n = 26), fathers (n = 12), and unrelated individuals (n = 60) who served as controls. Alloresponse capabilities and stimulation capacities of CB-MNC in the SMLR were similar to those of control MNC: relative response (RR) = 73 vs. 65 and 58 vs. 65, respectively. Similar results were obtained in the MMLR. CB-MNC responded weakly to the maternal MNC in comparison with control MNC (RR = 47 vs. 73 [p = 0.0099]), while a stronger response was noted to the paternal than the maternal MNC (RR = 72 vs. 47 [p = 0.045]). Our results demonstrate that CB-MNC both respond to and induce alloresponse in HLA mismatched combinations. Moreover, the hyporesponse of CB-MNC to maternal cells that we observed suggests a form of tolerance to NIMA, which is probably due to the fetus's exposure to these antigens in its intrauterine life.

Positivity in a modified mixed leukocyte reaction test correlates with molecular HLA-C disparity in prediction of unrelated bone marrow transplantation outcome.

The modified mixed leukocyte reaction (MMLR) test consists of the standard MLR (SMLR) test to which interleukin-4 (IL-4) has been added. It is a sensitive procedure capable of detecting alloreactivity not detected by the SMLR. In the present study we applied the MMLR test to unrelated bone marrow transplantation (BMT) in an attempt to predict graft versus host disease (GVHD) and graft rejection (GR) by detecting alloreactivity between recipient/donor pairs otherwise found to be fully matched (HLA class I A and B tested by serology; class II DRB1 and DQB1 by sequence specific oligonucleotide probes [SSOP]) and by studying the relationship of MMLR alloreactivity and HLA-C disparity in the prediction of transplant related complications. Thirty-five patients transplanted from unrelated donors were included in the study. The MMLR test was seen to correlate with the incidence of transplant related complications, as of the 19 positive, cases 12 (63%) developed acute GVHD and 7 (37%) GR, while of the 16 negative cases only 5 (31%) developed GVHD (4 acute, 1 chronic) (p = 0.0001) and 2 (12.5%) GR. No such correlation was seen between the SMLR and the incidence of transplant related complications: the SMLR test was positive in only 4 (11%) cases (all of which developed GVHD or GR) but of the 31 negative cases 22 (71%) also developed GVHD or GR. Reactivity in the MMLR also correlated with molecular HLA-C disparity (p = 0.015): While of the 19 positive cases 10 (53%) had molecular HLA-C disparity, of the 16 cases with negative MMLR, 14 (87.5%) were matched for molecular HLA-C. Two-way analysis confirmed that patients with positive MMLR transplanted from HLA-C mismatched donors were more likely to develop post BMT complications, including GVHD and GR, than patients with negative MMLR transplanted from HLA-C matched donors (r = +0.70) (p = 0.001). We conclude that the MMLR test may be a useful tool in the prediction of transplant related complications such as GVHD and GR, post unrelated BMT. Moreover, the MMLR test, in conjunction with molecular HLA-C typing, may improve unrelated donor selection.

Dysregulation of inflammatory cytokines in unrelated bone marrow transplantation.

The dysregulation of cytokines is thought to play a role in the inflammatory and allospecific components of graft-versus-host disease (GVHD) and graft rejection (GR) post allogeneic bone marrow transplantation (BMT). Both complications occur post unrelated BMT at significantly higher frequencies than post BMT from identical sibling donors. The levels of tumor necrosis factor alpha (TNF-alpha) and interleukin (IL)-1beta, IL-6, IL-10 and IL-12 following unrelated BMT were measured to examine cytokine dysregulation involvement in GVHD and GR. Of the 26 patients included in this study, 15 developed GVHD (14 acute; 1 acute and chronic), 5 had GR and 6 had uneventful BMT. TNF-alpha was markedly elevated in 13/15 of the patients with GVHD and in 3/5 patients with GR. IL-6 was elevated in patients with acute GVHD and with GR. IL-12 levels were similar in pre- and post-BMT sera. No correlation was found between HLA-C match and cytokine levels. In conclusion, a positive correlation was found between elevated levels of TNF-alpha, IL-6 and IL-10, and GVHD (p < 0.05, p < 0.005 and p < 0.002 respectively) and GR (p < 0.01).

Cytokine production in human mixed leukocyte reactions performed in serum-free media.

The mixed leukocyte reaction (MLR) is an in vitro test commonly performed in a serum-containing medium (SCM), and used to study allorecognition and cellular immunity accompanied by cytokine release. We investigated the possibility of performing the MLR test in serum-free media (SFM) by comparing human leukocyte proliferation and cytokine release in MLRs performed in SFM and SCM. Of the four SFM tested, only Biotarget- was as effective as SCM in supporting leukocyte proliferation and IL-2 secretion. Both phenomena were observed only in allogeneic combinations. The levels of IL-1, IL-6, and TNFalpha in allogeneic MLR combinations in SFM were half those in SCM cultures; the kinetics of their release were the same. With the exception of IL-2, a high degree of spontaneous release of the other three cytokines analyzed was observed in responder cells, in irradiated stimulator cells, and in autologous combinations cultured in both SCM and SFM. It appears that unlike IL-2, the cytokines IL-1, IL-6, and TNFalpha are nonspecifically produced in MLR and cannot serve as sensitive indices of HLA disparity.

Enhanced lymphoid cell recovery after bone marrow transplantation: correlation with the presence of costimulatory antibodies in serum.

We describe a patient with T cell deficiency who underwent bone marrow transplantation (BMT) from an HLA-identical brother. The patient's white blood cell count recovered with exceptional rapidity post-BMT: after 7 to 9 days it rose sharply to 98x10(9) cells/L, 76% of which were mononuclear leukocytes. It then decreased, and a second peak was observed 250 days post-BMT. Lymphocytes from both peaks displayed a phenotype of mature T cells together with characteristics of a constitutively activated state; that is, they 1) exhibited high levels of tyrosine-phosphorylated T cell receptor (TCR) zeta chain, 2) spontaneously secreted IL-2, 3) expressed activation specific cell surface markers, and 4) were unresponsive to in vitro stimuli. The increased cell counts in both peaks correlated with the presence of anti-lymphocytic antibodies in the patient's serum, which reacted with peripheral blood lymphocytes (PBLs) both from the donor and from unrelated individuals. These antibodies were present before BMT and reappeared post-BMT. Variable number tandem repeats analysis revealed that the patient's PBLs were chimeras for up to 2 years post-BMT. This finding could explain the newly synthesized post-BMT anti-lymphocytic antibodies and the appearance of the second WBC peak during that period. The patient's anti-lymphocytic antibodies displayed costimulatory activity, enhancing the in vitro proliferation of normal T cells suboptimally activated via the TCR. The unique characteristics of these antibodies could explain the enhanced T cell recovery observed post-BMT as well as the constitutive activation state of these cells. Furthermore, such antibodies may eventually facilitate development of a therapeutic method for inducing enhanced post-BMT recovery.

HLA and graft-versus-host disease: a population-based study of HLA phenotypes of Jewish and Arabic bone marrow transplanted patients in Israel.

The relationship between the incidence of graft-versus-host disease (GVHD) and human leukocyte antigens (HLA) was analyzed in HLA-identical sibling bone marrow transplantation donor/recipient pairs from the two major populations in Israel: Jewish and Arabic. HLA phenotypes were significantly different, in both groups, between patients and healthy controls. Among Jews, a higher incidence of GVHD was found with A28, CW3, CW6 of class I and DR7, DQ2 of class II; a lower incidence was found with A2, A26, B14. Among Arabs, a higher incidence of GVHD was found with B41, CW7 of class I, and DR2, DR13 of class II. The development of GVHD is apparently associated with HLA phenotypes specific to each population.

Bone marrow transplantation using unrelated and family related donors: the impact of HLA-C disparity.

The clinical outcomes of unrelated and of family related allogeneic bone marrow transplantation (BMT) were correlated with HLA disparity in a study in which molecular phenotyping of HLA-C was performed for unrelated donor-recipient pairs. The study included 30 patients who underwent BMT from unrelated donors and 43 patients who underwent BMT from family related donors. The unrelated group included 14 full match pairs, 12 class-I-C (molecular HLA-C) mismatched pairs, and 4 haploidentical pairs. The family related group included 9 full match pairs, 19 class-I mismatched pairs, and 15 haploidentical pairs. In the unrelated BMT group, the transplant-related complications of mortality, graft-versus-host disease (GVHD), and graft rejection, were significantly higher in molecular HLA-C mismatched than matched patients (67% vs 14%, P < 0.02; 50% vs 7%, P < 0.02; 42% vs 0, P < 0.02). The actuarial survival and the disease free survival (DFS) at 18 months was better for molecular HLA-C matched than for HLA-C mismatched unrelated transplants: 33% vs 18% (P = 0.065, NS), and 29% vs 16%, respectively. For the family related BMT group, the actuarial survival at 18 months was significantly higher for patients who were fully matched compared to those who were class-I mismatched, or those who were haploidentical pairs: 67%, 37%, and 13% respectively (P < 0.02). The actuarial DFS at 18 months of patients who were fully matched and of those who were class-I mismatched was similar, and better than that of haploidentical patients 45%, 37% (NS) and 13% respectively (P < 0.045). A lower incidence of transplant-related mortality occurred in class-I mismatched, family related (37%) than in locus-C mismatched unrelated patients (67%), and no difference was observed in the fully matched family related and unrelated patients. We conclude that a mismatch in locus C may be detrimental to BMT outcome and should therefore be included as a risk factor in the routine pre-BMT HLA phenotyping.