The Incremental Cost of Incompatible Living Donor Kidney Transplantation: A National Cohort Analysis.

Incompatible living donor kidney transplantation (ILDKT) has been established as an effective option for end-stage renal disease patients with willing but HLA-incompatible living donors, reducing mortality and improving quality of life. Depending on antibody titer, ILDKT can require highly resource-intensive procedures, including intravenous immunoglobulin, plasma exchange, and/or cell-depleting antibody treatment, as well as protocol biopsies and donor-specific antibody testing. This study sought to compare the cost and Medicare reimbursement, exclusive of organ acquisition payment, for ILDKT (n = 926) with varying antibody titers to matched compatible transplants (n = 2762) performed between 2002 and 2011. Data were assembled from a national cohort study of ILDKT and a unique data set linking hospital cost accounting data and Medicare claims. ILDKT was more expensive than matched compatible transplantation, ranging from 20% higher adjusted costs for positive on Luminex assay but negative flow cytometric crossmatch, 26% higher for positive flow cytometric crossmatch but negative cytotoxic crossmatch, and 39% higher for positive cytotoxic crossmatch (p < 0.0001 for all). ILDKT was associated with longer median length of stay (12.9 vs. 7.8 days), higher Medicare payments ($91 330 vs. $63 782 p < 0.0001), and greater outlier payments. In conclusion, ILDKT increases the cost of and payments for kidney transplantation.

Quantifying the risk of incompatible kidney transplantation: a multicenter study.

Incompatible live donor kidney transplantation (ILDKT) offers a survival advantage over dialysis to patients with anti-HLA donor-specific antibody (DSA). Program-specific reports (PSRs) fail to account for ILDKT, placing this practice at regulatory risk. We collected DSA data, categorized as positive Luminex, negative flow crossmatch (PLNF) (n = 185), positive flow, negative cytotoxic crossmatch (PFNC) (n = 536) or positive cytotoxic crossmatch (PCC) (n = 304), from 22 centers. We tested associations between DSA, graft loss and mortality after adjusting for PSR model factors, using 9669 compatible patients as a comparison. PLNF patients had similar graft loss; however, PFNC (adjusted hazard ratio [aHR] = 1.64, 95% confidence interval [CI]: 1.15-2.23, p = 0.007) and PCC (aHR = 5.01, 95% CI: 3.71-6.77, p < 0.001) were associated with increased graft loss in the first year. PLNF patients had similar mortality; however, PFNC (aHR = 2.04; 95% CI: 1.28-3.26; p = 0.003) and PCC (aHR = 4.59; 95% CI: 2.98-7.07; p < 0.001) were associated with increased mortality. We simulated Centers for Medicare & Medicaid Services flagging to examine ILDKT's effect on the risk of being flagged. Compared to equal-quality centers performing no ILDKT, centers performing 5%, 10% or 20% PFNC had a 1.19-, 1.33- and 1.73-fold higher odds of being flagged. Centers performing 5%, 10% or 20% PCC had a 2.22-, 4.09- and 10.72-fold higher odds. Failure to account for ILDKT's increased risk places centers providing this life-saving treatment in jeopardy of regulatory intervention.

DonorNet and the potential effects on organ utilization.

The evolution of communication as donor data flows from organ procurement organization to transplant centers has evolved with the incorporation of DonorNet 2007 into the UNet(SM) system. The ensuing study looks at DonorNet's impact on this process. We established defined time periods for comparison purposes. The study looked at match number for organ placement and overall organ utilization with a focus on ischemia time and graft outcomes. The results of the study demonstrate no significant change in the median match number of organ placement in liver or kidney transplantation. Changes in discard rates were varied amongst transplanted organs and there were noticeable changes in organ sharing with an increase in local allocation for kidney and liver and an ensuing decrease in regional and national distribution. There were no significant differences in the outcomes of livers and kidneys with low offer numbers compared with those with high offer numbers. Overall the study suggests a modest impact by DonorNet on organ placement and utilization, but a longer term study would need to be done to fully evaluate its impact.

Low free serum histidine concentration in rheumatoid arthritis. A measure of disease activity.

A study of sera from 285 patients with definite or classical rheumatoid arthritis (including 37 patients receiving no anti-inflammatory drugs) and sera from 67 healthy subjects has confirmed 10 published reports of a statistically significant decreased blood histidine concentration in patients with rheumatoid arthritis. Contrastingly, in sera from 231 patients with a variety of acute and chronic illnesses other than rheumatoid arthritis, no statistically significant hypohistidinemia was observed either in the group as a whole or in association with the administration of aspirin, prednisone, indomethacin, phenylbutazone, or dextropropoxyphene. In the patients with rheumatoid arthritis there was a statistically significant correlation between the serum histidine concentration and the following: Westergren sedimentation rate (r=-0.33, P smaller than 10- minus 9), grip strength (r=0.26, P smaller than 10- minus 9), hematocrit (r=0.23, P smaller than 10- minus 9), duration of morning stiffness (r=-0.14, P=10- minus 5), walking time (r=-0.13, P=10- minus 4), latex titer of rheumatoid factor (r=-0.11, P=0.001), and the duration of arthritis (r=-0.06, P=0.05). There was no statistically significant association between the serum histidine concentration and the duration of rheumatoid arthritis in the 151 patients with disease of 0-10-yr duration (r=0.02, P=0.5), the sex of the patient, or the presence of antinuclear antibody (R=0.007, P=0.9). The serum histidine concentration was less in rheumatoid patients receiving steroids (P=0.00001), gold (P=0.009), and aspirin (P=0.15) than in rheumatoid patients not receiving these drugs. This study indicates that histidine determinations on properly preserved casual serum samples can be helpful in the diagnosis of rheumatoid arthritis and in the evaluation of the activity of the disease.

[In vitro evidence for pancreatic lineage: Ngn3 positive cells are endocrine progenitors derived from cultured islets].

OBJECTIVE: Further studies have been conducted to evaluate the roles of Ngn3 in adult islet maintenance and renewal. METHODS: Islets were isolated from 6 - 8 week old male C57BL/6 mice. After common bile duct cannulation, the pancreas was resected and digested in collagenase V (2.5 mg/ml). Islets were then handpicked and 10 - 12 islets were plated in 60 mm culture dish and cultivated with RPMI-1640, which contained 12.5 mmol/L HEPES, 5.2 mmol/L glucose and 2% fetal bovine serum (FBS). Islet cells were analyzed by immunocytochemistry methods for A6, insulin, glucagon, nestin, Ngn3 and 5-bromo-2'-deoxy-uridine (BrdU). RESULTS: The results of these studies indicated that less than 15 percent of proliferated islet cells were Ngn3 expressing cells, in which about one third of the Ngn3 positive cells co-expressed A6. The existence of Ngn3 in cultured islet cells is consistent with the results from other's findings both in embryogenesis and adult islet studies. A significant finding of our study is that the existence of A6 and Ngn3 co-expressing cells in the cultured islet. A6 is a marker for identifying bile duct epithelial cell oriented hepatic progenitor cells. Islet-derived A6 cells are possibly born in the adult pancreatic duct and migrate into islets. A6 cells co-express Ngn3 when these cells commit to endocrine lineage within the islets. More interestingly, islet-derived A6 positive cells have the potential to transdifferentiate into hepatic cells. CONCLUSION: The presence of Ngn3(+) and A6(+) cells in the cultured islets suggests that the four established islet cell types arise from a common endocrine lineage residing within the adult islets. A6 and Ngn3 are useful markers for understanding intra-islet adult stem cell lineages in our future studies. This approach may allow for significant advances in understanding the IPC proliferation and differentiation, and open the possibility of using intra-islet adult stem cells for diabetes treatment.

Free serum histidine levels in patients with rheumatoid arthritis and control subjects following an oral load of free L-histidine.

A dose of 3.7 g of free-L-histidine was administered by mouth to 26 patients with active rheumatoid arthritis and to 29 control subjects. The patients with rheumatoid arthritis had a statistically significant (p=10(-12)) lower pretreatment concentration of free histidine in serum (1.20 mg/100 ml, SE=0.04) than the control subjects (1.90 mg/100 ml, SE=0.06). However, there were no statistically significant differences between rheumatoid and control subjects with respect to the serum histidine concentrations 1 hr, 3 hr, and 4 hr after the ingestion of L-histidine. The changes in the serum histidine concentrations at 1 hr, 3 hr, and 4 hr (compared to the pretest values) were also not significantly different in the patients with rheumatoid arthritis relative to the control subjects. This study suggests that the subnormal free serum histidine concentration of rheumatoid arthritis is not associated with abnormal serum levels of free histidine following an oral load of free histidine.

Prolongation of murine cardiac allograft survival by microspheres containing TNF alpha and IL1-beta neutralizing antibodies.

Efficient delivery of therapeutic agents to a critical microenvironment may increase the efficacy of drugs used to modulate the allograft rejection response. This study demonstrates the ability of the combination of microspheres containing neutralizing anti-TNF alpha and anti-IL1-beta antibodies to significantly prolong murine cardiac allograft survival. These results suggest that the microsphere technique is an efficacious method to target antibody delivery to prolong allograft survival.

A model utilizing adult murine stem cells for creation of personalized islets for transplantation.

Clinical islet cell transplantation has demonstrated great promise for diabetes treatment. Two major obstacles are the organ donor shortage and the immunoresponse. The purpose of this study was to create a model using the patient's own adult stem cell sources, possibly in combination with non-self cells, such as pancreatic, hepatic, or embryonic stem cells, to create "personalized" islets. We hypothesize that the reconstructed islets have the normal capability to produce insulin and glucagon with reduced immunoresponses after transplantation. Stem cells are a proliferating population of master cells that have the ability for self-renewal and multilineage differentiation. The recently developed photolithograph-based, biologic, microelectromechanic system (BioMEMS) technique supplies a useful tool for biomedical applications. Our lab has developed a novel method that integrates the adult stem cell and BioMEMS to reconstruct personalized islets. We selected islet-derived progenitor cells (IPC) for repairing and reconstructing STZ-diabetic islets. A6(+)/PYY(+) or A6(+)/ngn3(+) cells were selected to manipulate the neoislets. After 3 to 4 weeks in culture, the reconstructed cells formed islet-like clusters containing insulin or glucagon producing cells. The pilot results showed the ability of these reconstructed islets to correct hyperglycemia when transplanted into a STZ-diabetic isograft mouse model. Although several technical problems remain with the mouse model, namely, the difficulty to collect enough islets from a single mouse because of animal size, the mouse isograft model is suitable for personalized islet development.

Isolated donor specific alloantibody-mediated rejection after ABO compatible liver transplantation.

Antibody-mediated rejection (AMR) after liver transplantation is recognized in ABO incompatible and xeno-transplantation, but its role after ABO compatible liver transplantation is controversial. We report a case of ABO compatible liver transplantation that demonstrated clinical, serological and histological signs of AMR without evidence of concurrent acute cellular rejection. AMR with persistently high titers of circulating donor specific antibodies resulted in graft injury with initial centrilobular hepatocyte necrosis, fibroedematous portal expansion mimicking biliary tract outflow obstruction, ultimately resulting in extensive bridging fibrosis. Immunofluorescence microscopy demonstrated persistent, diffuse linear C4d deposits along sinusoids and central veins. Despite intense therapeutic intervention including plasmapheresis, IVIG and rituximab, AMR led to graft failure. We present evidence that an antibody-mediated alloresponse to an ABO compatible liver graft can cause significant graft injury independent of acute cellular rejection. AMR shows distinct histologic changes including a characteristic staining profile for C4d.

Antirheumatic drugs, the ESR, and the hypohistidinemia of rheumatoid arthritis.

The longterm administration of prednisone and gold to patients with rheumatoid arthritis (RA), in doses that decreased the sedimentation rate (p less than 0.05), did not alter the serum histidine concentration (p greater than 0.5). In patients with RA receiving various combinations of aspirin, prednisone, and gold, the regression lines relating the serum histidine concentrations to the sedimentation rates had similar slopes but different elevations compared to patients receiving no anti-inflammatory drugs. In the patients receiving anti-inflammatory drugs, the regression lines were displaced so that in patients with similar serum histidine concentrations, the stronger the antirheumatic therapy, the less abnormal the sedimentation rate. These observations are consistent with the hypothesis that hypohistidinemia contributes to the pathogenesis of RA.

Decreased concentration of free histidine in serum in rheumatoid arthritis, an isolated amino acid abnormality not associated with generalized hypoaminoacidemia.

The serum concentrations of 12 free amino acids (alanine, arginine, glycine, histidine, isoleucine, leucine, lysine, phenylalanine, serine, threonine, tyrosine, and valine) were measured in 26 patients with rheumatoid arthritis and in 12 control subjects. Patients with rheumatoid arthritis had a low serum histidine concentration (P equals 0.002) but no abnormality of any other amino acid concentration or of the combined concentration of the measured amino acids, excluding histidine. These data and 22 other reported studies provide strong evidence for the presence of hypohistidemia, not associated with generalized hypoaminoacidemia, in patients with rheumatoid arthritis. (J Rheumatol 2: 384-392, 1975).

Sulfhydryl-dependent thermal aggregation of human gamma globulin: augmentation by hyaluronic acid.

Hyaluronic acid (4 mg/ml) augmented elevenfold the copper-catalyzed (7 muM) thermal (63 degrees C, 2 hours) aggregation of human gamma globulin (2 mg/ml) in 0.075 M phosphate buffer, pH 7.4. Almost no augmentation of aggregation occurred with hyaluronidase-treated hyaluronate. Hyaluronate-augmented copper-catalyzed thermal aggregation was inhibited by L-histidine, gold thiomalate, N-ethylmaleimide, p-chloromercuribenzoic acid, and ethylenediaminetetraacetic acid. Together with previous reports of a decreased blood histidine concentration in rheumatoid arthritis, these studies provide a possible explanation for the affinity of this disease for joints.

Possible role of a copper complex in the pathogenesis of rheumatoid arthritis.

Clinical and experimental evidence suggest that rheumatoid arthritis may be due to a deficiency in joint fluid of an inhibitor of protein denaturation. This inhibitor may be a histidine-cystine-copper complex. A deficiency of this inhibitor may permit the nonimmunological alteration of joint fluid IgG to a pseudoimmune complex which could initiate the inflammation and immunological abnormalities of rheumatoid arthritis.

Inhibition of denaturation of human gamma globulin by a mixture of L-histidine, L-cystine, and copper, and its clinical implication in rheumatoid arthritis.

A mixture of histidine, cystine, and copper mimicked gold thiomalate, N-ethylmaleimide, and p-chloro-mercuribenzoic acid in inhibiting sulfhydryl-disulfide interchange-mediated denaturation of human gamma globulin, bovine serum albumin, and diluted human serum. Measurable inhibitory effects were obtained with a mixture of physiologic concentrations of L-histidine, L-cystine, and copper. This work suggests a mechanism by which the hypohistidinemia of rheumatoid arthritis could contribute to the pathogenesis of the disease.