A retrospective study to determine the risk of red cell alloimmunization and transfusion during pregnancy

A retrospective review of post-delivery antibody records was performed at a teaching hospital and a community hospital to determine the frequency of new red cell alloantibody production and transfusion during pregnancy. If alloantibody was undetected at delivery, it was assumed that alloimmunization had not occurred. When antibody was detected, a chart review was performed to determine if the antibody was present at the beginning of the pregnancy or was newly produced during the pregnancy. A total of 17,568 pregnancies were reviewed. Antibody was detected at delivery in 948 (5.4%) cases, of which 89.5 percent (848/948) involved passive anti-D or clinically insignificant antibodies. The remaining 100 pregnancies involved clinically significant IgG antibodies. In 58 pregnancies, the antibody was detected in the first trimester, and in 42, new antibody production occurred during the pregnancy. Thus, the prevalence of new antibody production during pregnancy was 0.24 percent (95% confidence interval [CI], 0.17-0.32). Transfusion records indicated that the prevalence of transfusions during pregnancy was 0.09 percent (95% CI, 0.04-0.14). None of the women with new alloantibody formation during their pregnancies required transfusion; hence, new alloantibody production and the need for transfusion appear to be independent events. The probability of these events occurring together was 2.1 × 10(-6), or 1 in 500,000 deliveries.     

A randomized controlled trial comparing plasma removal with white cell reduction to prevent reactions to platelets

BACKGROUND: Recent data suggest that most reactions to platelets are caused by white cell (WBC)-derived cytokines that accumulate in the plasma portion of the component during storage. On the basis of this theory, the effectiveness of two interventions to prevent reactions, poststorage WBC reduction and plasma depletion, were compared. STUDY DESIGN: A multiple crossover design was used, in which platelet components for transfusion to a patient randomly were WBC reduced after storage, or the plasma supernatant was removed. Adults >17 years of age, with a hematologic disease requiring platelet transfusion support, were eligible for the study. Patients were assessed for signs and symptoms characteristic of a reaction during, immediately after, and 1 hour after transfusion. Reactions were graded as mild, moderate, or severe. Interleukin 6 levels were also measured in the transfused platelet components. RESULTS: There were 380 analyzable platelet transfusions to 30 patients. The frequency of reactions was 25.8 percent (48/186) in the transfusions of poststorage WBC-reduced platelets and 17.0 percent (33/194) in the transfusions of plasma-depleted platelets (p<0.008). The severity of the reaction was graded by the patient. Severe reactions occurred more frequently in connection with poststorage WBC-reduced platelets than with plasma-depleted platelets: 33.4 percent (16/48) versus 18.2 percent (6/33), respectively (p = 0.048). Regression analysis identified interleukin 6 as the most significant of the evaluated factors in its correlation with the risk of reaction. CONCLUSION: Plasma removal is more effective than poststorage WBC reduction in preventing reactions, especially severe reactions to platelets.     

Effect of Pulmonary Rehabilitation on Balance in Persons With Chronic Obstructive Pulmonary Disease

Beauchamp MK, O'Hoski S, Goldstein RS, Brooks D. Effect of pulmonary rehabilitation on balance in persons with chronic obstructive pulmonary disease.

Objectives

To describe within-subject effects of pulmonary rehabilitation (PR) on balance in persons with chronic obstructive pulmonary disease (COPD) and to determine whether any observed changes in balance were associated with change in exercise tolerance or health-related quality of life.

Design

Single-arm longitudinal study.

Setting

Inpatient PR center.

Participants

Subjects with COPD (N=29; mean ± SD age, 69.8±10.3y; forced expiratory volume in 1 second, 46.3%±22.3% predicted; 59% men [n=17]).

Interventions

A standardized 6-week multidisciplinary PR program (exercise training, breathing exercises, education, and psychologic support).

Main Outcome Measures

Balance was assessed using the Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and the Activities-Specific Balance Confidence (ABC) scale. Exercise tolerance was determined from the 6-minute walk test (6MWT), and health-related quality of life from the Chronic Respiratory Questionnaire (CRQ).

Results

Subjects showed small improvements in BBS (2.8±2.8 points; P<.001) and TUG (−1.5±2.4s; P=.003) scores, but not in ABC scores (4.8±15.4 points; P>.05). There was a weak relationship between change in BBS and change in CRQ scores (r=.40; P=.045) and no relationship with change in 6MWT.

Conclusions

PR contributed to minor improvements in balance and had no effect on balance confidence in subjects with COPD. Further work is warranted to determine the optimal intervention for improving balance in this population.     

Experience with an albumin-enhanced, 15-minute incubation, emergency crossmatch

During a 40-month period, an emergency crossmatch procedure using an albumin-enhanced 15 minute incubation indirect antiglobulin technique was evaluated along with a standard procedure for 2,276 patients involving 6,423 units of blood. One hundred-forty unsuspected allo- antibodies were detected during this study, of which 130 were detected by both techniques. In five instances where antibodies were not detected by the emergency technique, the antibodies were not though to be clinically significant.     

A prospective study to determine the frequency and clinical significance of alloimmunization post-transfusion

Summary. There is debate in the literature about the frequency and importance of delayed transfusion reactions. This uncertainty could reflect the endpoints used (clinical or serological) and the type of study (typically retrospective or case series). In this report we describe a prospective investigation to determine the frequency of alloimmunization post transfusion and whether the alloantibody production is a laboratory event or has clinical relevance.
A total of 2490 patients were transfused 11218 red cell concentrates. One or more blood samples were collected within 7 d post transfusion and screened for serological evidence of alloimmunization. If any antibody was detected the patient's post-transfusion sample was screened for biochemical evidence of haemolysis and the patient's chart reviewed for documentation of clinical signs of a transfusion reaction. Post transfusion alloimmunization occurred in 2.6% of the patients (95% CI 2.1–3.6%), who had no detectable alloantibody in pre-transfusion testing. For those 86 patients (3.5%) with alloantibodies detectable pretransfusion, 8.9% (95% CI 3.6–17.4%) developed additional aloantibodies. The most common alloantibodies detected were anti-Jk^a, anti-E and anti-K. Despite the high frequency of serological evidence of delayed transfusion reactions, only one patient (005%) had clinical evidence of a delayed haemolytic transfusion reaction (95% CI 0.0–0.27%). Serological evidence of a delayed transfusion reaction is common; however, these reactions rarely cause clinical symptoms.     

Rhesus alloimmunization following intensive plasma exchange

A 17-year-old woman was admitted to the hospital for the treatment of rapidly progressive systemic lupus erythematosus. She failed to improve when treatment with cyclophosphamide and prednisone and, therefore, was treated with intensive plasma exchange. A total of 24 liters of plasma was exchanged during six separate procedures over an 8-day period. The patient, who was blood group B Rh negative (Cde/cde), was found to have an IgG anti-D antibody reacting at a titer of 16 by the indirect antiglobulin technique 6 weeks after the first plasma exchange procedure. The titer of this antibody subsequently rose to 512. This patient, who had neither been pregnant nor received any blood products other than the plasma used during the plasma exchange, was presumably immunized by Rh positive red cells or stroma present in the transfused plasma. It is estimated that the patient received approximately 10(10) Rh positive cells, or approximately one ml of packed red cells–a quantity sufficient to cause Rhesus alloimmunization.     

Autologous peripheral blood progenitor cells are a potential source of parvovirus B19 infection

BACKGROUND: Parvovirus B19 is a cause of delayed red blood cell (RBC) engraftment after marrow transplantation (BMT). The diagnosis of parvovirus infection requires serologic and DNA testing in the context of clinical disease and characteristic marrow morphologic findings; however, the source of infection is often difficult to determine. STUDY DESIGN AND METHODS: Investigation of a case of delayed RBC engraftment and pure RBC aplasia (PRCA) occurring 3 months after autologous peripheral blood progenitor cell (PBPC) transplantation in a patient with high-risk diffuse large B-cell lymphoma. DNA testing of serum and of a sample of cryopreserved PBPCs was performed. RESULTS: Marrow morphology showed a maturational arrest of erythroid cells with giant proerythroblasts. Polymerase chain reaction and nucleic acid hybridization confirmed the presence of parvovirus DNA in the serum and in a sample of sequestered PBPCs saved at the time of PBPC harvest. PRCA resolved after the administration of intravenous immune globulin. CONCLUSION: Autologous PBPCs are a potential source of parvovirus infection, which may cause significant disease after autologous BMT.