Significance of complement split product C4d in ABO-compatible liver allograft: diagnosing utility in acute antibody mediated rejection.

Diagnosis of liver allograft antibody-mediated rejection (AMR) is difficult and requires a constellation of clinical, laboratory and histologic features that support the disease and exclude other causes. Histologic features of AMR may intermix with those of biliary obstruction, preservation/reperfusion injury, and graft ischemia. Tissue examination for complement degradation product 4d (C4d) has been proved to support this diagnosis in other allografts. For this reason, we conducted a retrospective review of all ABO compatible/identical re-transplanted liver patients with primary focus on identifying AMR as a possible cause of graft failure and to investigate the utility of C4d in liver allograft specimens. We reviewed 193 liver samples obtained from 53 consecutive ABO-compatible re-transplant patients. 142 specimens were stained with C4d. Anti-donor antibody screening and identification was determined by Luminex100 flow cytometry. For the study analysis, patients were stratified into 3 groups according to time to graft failure: group A, patients with graft failure within 0-7 days (n=7), group B within 8-90 days (n=13) and C >90 days (n=33). Two patients (3.7%) met the diagnostic criteria of acute AMR. Both patients experienced rapid decline of graft function with presence of donor specific antibodies (DSA), morphologic evidence of humoral rejection and C4d deposition in liver specimens. C4d-positive staining was identified in different medical liver conditions i.e., acute cellular rejection (52%), chronic ductopenic rejection (50%), recurrent liver disease (48%), preservation injury (18%), and hepatic necrosis (54%). Univariate analysis showed no significant difference of C4d-positive staining among the 3 patients groups, or patients with DSA (P>.05). In conclusion, AMR after ABO-compatible liver transplantation is an uncommon cause of graft failure. Unlike other solid organ allografts, C4d-positive staining is not a rugged indicator of humoral rejection, thus, interpretation should be done with caution to avoid diagnostic dilemmas.

Definitions of histocompatibility typing terms.

Histocompatibility testing for stem cell and solid organ transplantation has become increasingly complex as newly discovered HLA alleles are described. HLA typing assignments reported by laboratories are used by physicians and donor registries for matching donors and recipients. To communicate effectively, a common language for histocompatibility terms should be established. In early 2010, representatives from Clinical, Registry, and Histocompatibility organizations joined together as the Harmonization of Histocompatibility Typing Terms Working Group to define a consensual language for laboratories, physicians, and registries to communicate histocompatibility typing information. The Working Group defined terms for HLA typing resolution, HLA matching, and a format for reporting HLA assignments. In addition, definitions of verification typing and extended typing were addressed. The original draft of the Definitions of Histocompatibility Typing Terms was disseminated to colleagues from each organization to gain feedback and create a collaborative document. Commentary gathered during this 90-day review period were discussed and implemented for preparation of this report. Histocompatibility testing continues to evolve; thus, the definitions agreed on today probably will require refinement and perhaps additional terminology in the future.

Definitions of histocompatibility typing terms: Harmonization of Histocompatibility Typing Terms Working Group.

Histocompatibility testing for stem cell and solid organ transplantation has become increasingly complex as newly discovered human leukocyte antigen (HLA) alleles are described. HLA typing assignments reported by laboratories are used by physicians and donor registries for matching donors and recipients. To communicate effectively, a common language for histocompatibility terms should be established. In early 2010, representatives from clinical, registry, and histocompatibility organizations joined together as the Harmonization of Histocompatibility Typing Terms Working Group to define a consensual language for laboratories, physicians and registries to communicate histocompatibility typing information. The Working Group defined terms for HLA typing resolution, HLA matching and a format for reporting HLA assignments. In addition, definitions of verification typing and extended typing were addressed. The original draft of the Definitions of Histocompatibility Typing Terms was disseminated to colleagues from each organization to gain feedback and create a collaborative document. Commentary gathered during this 90-day review period were discussed and implemented for preparation of this report. Histocompatibility testing continues to evolve thus, the definitions agreed upon today, likely will require refinement and perhaps additional terminology in the future.

An audit on the current practice of red blood cell transfusion following elective primary hip arthroplasty.

This audit encompassing a six-month period on the current practice of red blood cell transfusion following elective primary total hip arthroplasty showed that the rate of allogeneic blood avoidance was 84.8% for preoperative autologous blood donors and 47.8% for non-donors (p<0.001). Lower preoperative hemoglobin level was associated with an increased allogeneic unit transfusion (p<0.001). The intraoperative use of autologous blood collection and transfusion systems did not reduce the transfusion risk, and the use of the colloid volume expander was associated with a 1.8-fold increased risk of transfusion (p=0.022).

Impact of acute blood loss anemia and red blood cell transfusion on mortality after percutaneous coronary intervention.

The clinical impact of increasing levels of blood loss has been shown to increase morbidity and mortality after percutaneous coronary intervention (PCI). The impact of red blood cell (RBC) transfusion for severe bleeding is unknown. We systematically collected baseline and 8-h postprocedure hematocrit (HCT) values on patients undergoing PCI. The incidence of adverse events, including death and recurrent myocardial infarction, was correlated to increasing blood loss. A total of 6,799 patients undergoing PCI (January 2000 to April 2002) had serial HCT levels. Negligible, mild, moderate, and severe blood loss occurred in 43, 25, 25, and 8% of patients, respectively. In-hospital mortality was 0.3, 0.5, 1.4, and 5.7% (p < 0.0001) with increasing severity of blood loss. Blood transfusion was independently associated with mortality (relative risk [RR] 2.03, p = 0.028). A case-controlled analysis of 146 transfused patients versus 292 nontransfused patients with severe bleeding found an independent association between RBC transfusion and increased risk of 1-year mortality (RR 2.42, p = 0.0045). Patients receiving blood >35 days old had significantly worse 1-year survival rates compared with patients receiving blood <35 days old and patients not transfused (36 vs. 24 vs. 10%, p < 0.0001). In a general PCI population, increasing levels of blood loss are associated with an increased incidence of major adverse cardiac events and in-hospital mortality. RBC transfusion in the setting of severe bleeding is associated with an increased risk of 1-year mortality. Transfusion of aged RBCs may also be detrimental in this setting.