Seek and you shall find--but then what do you do? Cold agglutinins in cardiopulmonary bypass and a single-center experience with cold agglutinin screening before cardiac surgery.

Cardiopulmonary bypass (CPB) during cardiac surgery can involve deliberate hypothermia of the systemic (22-36 °C) and coronary circulations (as low as 8-12 °C). Adverse sequelae of cold-active antibodies have been feared and reported under such conditions, and some centers thus elect to screen for cold agglutinins before CPB. We reviewed the literature on cold agglutinins in cardiac surgery and described the yields and effects of cold agglutinin screening (CAS) in 14,900 cardiac surgery patients undergoing CPB over 8 years at a single institution. Cold agglutinin screening was positive in 47 cases (0.3%), at an annual testing cost of $17,000 CAD. The response of the surgical team to the preoperative discovery of a cold agglutinin was variable, with CPB modified to avoid hypothermia in approximately one-third of cases. In patients discovered to have a positive CAS, postoperative intensive care unit and hospital length of stay were marginally increased (54.6 vs. 42.8 hours, P = .02; 7 [6-14] vs. 7 [5-9] days, P = .04). However, the composite of mortality or severe morbidity (stroke, myocardial infarction, dialysis, low output syndrome, sepsis, and deep vein thrombosis) was not significantly different (14.9% vs. 9.2%, P = .2). Antibody verification found that only 43% of positive CAS patients had true cold agglutinins (20 patients). Furthermore, the rate of adverse events was low in both CAS-positive and true-positive cold agglutinin patients undergoing CPB and cardiac surgery. Finally, modification of CPB to attenuate hypothermia did not decrease adverse events. Based upon historical and local data, preclinical CAS is cost-substantial and nonspecific. Cold agglutinin screening does not promote an algorithm of care that meaningfully improves patient CPB outcomes.

Passenger lymphocyte syndrome with or without immune hemolytic anemia in all Rh-positive recipients of lungs from rhesus alloimmunized donors: three new cases and a review of the literature.

The passenger lymphocyte syndrome (PLS) is an unusual complication of solid organ transplantation, in which donor lymphocytes produce antibodies reactive with host red blood cell (RBC) antigens. Risks for PLS include highly lymphoid grafts, past sensitization of the donor against relevant RBC antigens, and donor lymphocyte escape of host immune clearance. For a 1-year period at our center, we observed an uncommonly high frequency of post-lung transplant Rhesus PLS, occurring once in every 31 cases. Passenger lymphocyte syndrome resulted from 2 alloimmunized cadaveric donors, in 3 of 3 D+, ABO-identical but HLA-unmatched recipients who initially had nonreactive RBC antibody screens. In case 1, the right lung of a group A, D-negative donor, with antibodies against D, C, and E antigens, was transplanted into a group A, R1R1 recipient. The recipient developed severe hemolytic anemia, direct antiglobulin test (DAT)-positive, on postoperative day (POD) 17. Anti-D and anti-C were identified on both the indirect antiglobulin test (IAT) and the RBC eluate. She required 10 U of RBCs in 40 days as well as plasmapheresis (POD 36-40). When transfusion dependence ceased, anti-D +/- C remained detectable on DAT and IAT for another 6.5 months. In case 2, the group A, R1r recipient of the same donor's left lung exhibited anti-D for the first time at posttransplant month 4 on both IAT and DAT. This activity persisted until a rejection episode 5 months later, without ever causing any evidence of hemolysis. In case 3, the group O, R1R1 recipient of both lungs of a group O, D-negative donor, with antibodies against D, C, and V antigens, developed a nonhemolytic DAT and IAT with anti-D +/- C at postoperative month 2, which remained positive at last follow-up (6 months posttransplant). In conclusion, this report suggests a high incidence of Rhesus antibody PLS after lung transplantation, with wide variations in the timing of antibody onset, persistence, and severity. A review of the phenomenon and its implications are discussed.

Proceedings of a Consensus Conference: pathogen inactivation-making decisions about new technologies.

Significant progress has been made in reducing the risk of pathogen transmission to transfusion recipients. Nonetheless, there remains a continuing risk of transmission of viruses, bacteria, protozoa, and prions to recipients. These include many of the viruses for which specific screening tests exist as well as pathogens for which testing is currently not being done, including various species of bacteria, babesiosis, variant Creutzfeld-Jacob disease, hepatitis A virus, human herpes virus 8, chikungunya virus, Chagas disease, and malaria. Pathogen inactivation (PI) technologies potentially provide an additional way to protect the blood supply from emerging agents and also provide additional protection against both known and as-yet-unidentified agents. However, the impact of PI on product quality and recipient safety remains to be determined. The purpose of this consensus conference was to bring together international experts in an effort to consider the following issues with respect to PI: implementation criteria; licensing requirements; blood service and clinical issues; risk management issues; cost-benefit impact; and research requirements. These proceedings are provided to make available to the transfusion medicine community the considerable amount of important information presented at this consensus conference.

Hemolysis due to inadvertent hemodialysis against distilled water: Perils of bedside dialysate preparation.

OBJECTIVE: To describe the physiologic consequences of dialysis against distilled water and to provide recommendations by which other institutions may avoid similar errors in dialysate preparation. DATA SOURCE: Four cases of dialysis against distilled water are described, occurring at three teaching hospitals within a 2-yr period. In addition, an in vitro experiment of banked whole blood exposure to distilled water dialysate was performed. DATA EXTRACTION: Because all four cases occurred within a critical care setting, intensive monitoring of clinical, biochemical, and hematologic abnormalities was possible. DATA SYNTHESIS: Serum sodium decreased by an average of 22 mmol/L, followed by a decrease in hemoglobin averaging 32 g/L. Additional investigations and the in vitro experiment provided evidence that hemolysis occurred primarily via clearance of damaged erythrocytes within the patient's reticuloendothelial system. Physiologic derangements secondary to dialysis against distilled water likely contributed to a stroke suffered by one patient and the death of at least one other patient. CONCLUSIONS: Accidental dialysis against distilled water is a potentially serious but preventable complication of bedside dialysate preparation.