Autoantibody formation after alloimmunization inducing bystander immune hemolysis

The development of RBC autoantibodies resulting from or associated with allogeneic blood transfusions is not an easily determined complication of RBC transfusions. This report discusses one patient who developed RBC autoantibodies in association with an allogeneic blood transfusion and alloimmunization leading to a temporary bystander immune hemolysis. A 72-year-old woman was hospitalized as a result of severe anemia and received two units of ABO- and D-compatible RBCs. She had a history of two pregnancies 40 years before, but no history of RBC transfusion, and her antibody screen was negative. On the tenth day after transfusion her hemoglobin dropped, and alloanti-c was identified in her serum and eluate. At this time she received another two units of compatible blood according to her phenotype (group O, R1R1, K:-1). After 48 hours, she developed joint pain, pyrexia, and hemoglobinuria, and her Hb dropped from 9.2 g/dL to 5.3 g/ dL. The direct antiglobulin test was positive, an IgG autoantibody was present in the eluate, and the antibody investigation revealed the presence of anti-Jk(b) in addition to the previously identified alloanti-c. Her genotype was determined, and, based on the findings, two additional units were selected, found to be compatible, and transfused without incident. Transfusions were discontinued, and she was treated with IVIG and corticosteroids. Her Hb increased to 9.7 g/dL, and the patient made an uneventful recovery. It was concluded that transfusion of incompatible RBCs induced the formation of an autoantibody in this patient, resulting in lysis of bystander RBCs. The need for additional blood transfusion was successfully avoided by treatment with IVIG, steroid therapy, and rituximab.

Rituximab in refractory autoimmune diseases: Brazilian experience with 29 patients (2002-2004)

OBJECTIVE

Rituximab, a monoclonal antibody against B-lymphocytes that express CD 20, is already available for the treatment of non-Hodgkin's lymphoma. Due to the increased relevance of B-cell regulation in the pathogenesis of autoimmune diseases, rituximab is being used in the treatment of patients whose condition is refractory to conventional therapy.

METHODS

We retrospectively evaluated the short-term efficacy and tolerance of rituximab in patients with various autoimmune diseases who were treated at the Hospital Israelita Albert Einstein in the city of Sao Paulo.

RESULTS

During the period 2002-2004, 29 patients with various autoimmune diseases were treated with rituximab 375 mg/m2 for 4 consecutive weeks, or two doses of 1 g 2 weeks apart. We observed remarkable short-term results in all cases, except for one patient with thrombocytopenic purpura. Of note, we describe the results in two patients with diseases not previously treated with rituximab (hypergammaglobulinemic purpura of Waldenstrom and eosinophilic fasciitis with hypergammaglobulinemia). Treatment was well tolerated, with no unexpected adverse events. We also observed a marked reduction in steroid dosage.

CONCLUSION

Rituximab seems to be safe and effective in the treatment of patients with a variety of autoimmune diseases that are refractory to other modalities of treatment.

Evaluation of three methods for hemoglobin measurement in a blood donor setting

CONTEXT

The hemoglobin (Hb) level is the most-used parameter for screening blood donors for the presence of anemia, one of the most-used methods for measuring Hb levels is based on photometric detection of cyanmetahemoglobin, as an alternative to this technology, HemoCue has developed a photometric method based on the determination of azide metahemoglobin.

OBJECTIVE

To evaluate the performance of three methods for hemoglobin (Hb) determination in a blood bank setting.

DESIGN

Prospective study utilizing blood samples to compare methods for Hb determination.

SETTING

Hemotherapy Service of the Hospital Israelita Albert Einstein, a private institution in the tertiary health care system.

SAMPLE

Serial blood samples were collected from 259 individuals during the period from March to June 1996.

MAIN MEASUREMENTS

Test performances and their comparisons were assessed by the analysis of coefficients of variation (CV), linear regression and mean differences.

RESULTS

The CV for the three methods were: Coulter 0.68%, Cobas 0.82% and HemoCue 0.69%. There was no difference between the mean Hb determination for the three methods (p>0.05). The Coulter and Cobas methods showed the best agreement and the HemoCue method gave a lower Hb determination when compared to both the Coulter and Cobas methods. However, pairs of methods involving the HemoCue seem to have narrower limits of agreement (+/- 0.78 and +/- 1.02) than the Coulter and Cobas combination (+/- 1.13).

CONCLUSION

The three methods provide good agreement for hemoglobin determination.

Platelet aggregation and lipoprotein levels in a patient with familial hypercholesterolemia after selective LDL-apheresis

Platelet aggregation was studied in a patient with familial hypercholesterolemia immediately after apheresis selective for low-density lipoprotein (LDL), a lipid-lowering procedure. This treatment reduced plasmatic levels of total and LDL-cholesterol, apo B, and triglyceride. Increased platelet aggregation was reduced immediately after the apheresis in whole blood as well as in platelet-rich plasma. However, aggregation in washed platelets remained unchanged after LDL-apheresis. In conclusion, in this patient reduction of LDL-cholesterol improved platelet function in the very short term.