Identification of glycoprotein Ib as a target for autoantibody in idiopathic (autoimmune) thrombocytopenic purpura

An antibody (DIL) from a patient with idiopathic thrombocytopenic purpura (ITP) was shown to have autospecificity on the basis of reactions with autologous platelets that were identical to those obtained with platelets from normal subjects. DIL antibody also reacted strongly in an immunofluorescence test with platelets from a patient with Glanzmann's thrombasthenia, but failed to react with platelets from a patient with the Bernard-Soulier syndrome who was known to be deficient in glycoprotein Ib (GPIb). Purified GPIb and control platelets, but not Bernard-Soulier platelets, inhibited the lytic activity of DIL. Using the GPIb-specific monoclonal antibody AP1 and one-dimensional rocket electrophoresis into gels containing rabbit antihuman platelet membrane antibody, it was shown that staphylococcal protein A-Sepharose beads coated with DIL antibody selectively remove GPIb from solubilized platelet preparations. By crossed immunoelectrophoresis it was found that DIL recognizes a determinant on GPIb on the membrane side of the cleavage site of the platelet calcium- activated protease (calpain). These studies provide direct evidence for binding of a platelet autoantibody to a determinant on GPIb relatively close to the site of insertion of this protein into the platelet membrane.     

First-time donors responding to a national disaster may be an untapped resource for the blood centre

Background On 12 May 2008, a severe earthquake struck Sichuan in China. Many people donated blood for the first time, leading us to question whether these donors might become repeat donors in the future. The return pattern of post‐earthquake first‐time donors (PEFTD) was compared with that of first‐time donors (FTD) in a comparable period. Methods Demographic characteristics, transfusion‐transmissible infection rates and 1‐year return rates were compared between 5147 PEFTD (5/13‐5/19, 2008) and 3176 FTD (5/13‐5/19, 2009) from five Chinese blood centres using chi‐squared tests. Adjusted logistic regression was used to detect earthquake effect on donor return. Results Post‐earthquake first‐time donors were more frequently between 26 and 45 years, men, and better educated compared with the control group. Slightly higher but not statistically significant increased rates of hepatitis B virus surface antigen (HBsAg) (0·87% vs. 0·50%, P = 0·054), hepatitis C virus (HCV) (0·70% vs. 0·63%, P = 0·414), syphilis (0·9% vs. 0·7%, P = 0·489) and lower rates of human immunodeficiency virus (HIV) (0·31% vs. 0·60%, P = 0·078) reactivity were detected for PEFTD. The 1‐year return rate for PEFTD was significantly lower than that of the controls (8·0% vs. 13·0%, P < 0·001). After adjusting for demographic factors, donation volume and sites, the PEFTD were less likely to return in 1 year than the controls (OR: 0·520; 95% CI: 0·442, 0·611). Conclusion Post‐earthquake first‐time donors may be less likely to donate again without continuing motivation strategies. Further studies on PEFTD’s lack of motivation to return for donation are needed to design recruitment strategies to convert PEFTD to become repeat donors to continuously replenish the blood supply.     

Frailty and respiratory impairment in older persons

BackgroundAmong older persons, the association between frailty and spirometry-confirmed respiratory impairment has not been evaluated yet.MethodsBy using data on white participants aged 65 to 80 years (Cardiovascular Health Study, N = 3578), we evaluated cross-sectional and longitudinal associations between frailty and respiratory impairment, including their combined effect on mortality. Baseline assessments included frailty status (Fried phenotype: non-frail, pre-frail, and frail) and spirometry. Outcomes included development of frailty features (pre-frail or frail) at year 3 and respiratory impairment (airflow limitation or restrictive pattern) at year 4, and death (median follow-up, 13.2 years).ResultsAt baseline, 48.3% of participants were pre-frail, 5.8% of participants were frail, 13.8% of participants had airflow limitation, and 9.3% of participants had restrictive pattern; 46.1% of participants subsequently died. At baseline, pre-frail and frail were cross-sectionally associated with airflow limitation (adjusted odds ratio [OR], 1.62; 95% confidence interval [CI], 1.29-2.04 and adjusted OR 1.88; 95% CI, 1.15-3.09) and restrictive pattern (adjusted OR, 1.80; 95% CI, 1.37-2.36 and adjusted OR, 3.05; 95% CI, 1.91-4.88), respectively. Longitudinally, participants with baseline frailty features had an increased likelihood of developing respiratory impairment (adjusted OR, 1.42; 95% CI, 1.11-1.82). Conversely, participants with baseline respiratory impairment had an increased likelihood of developing frailty features (adjusted OR, 1.58; 95% CI, 1.17-2.13). Mortality was highest among participants who were frail and had respiratory impairment (adjusted hazard ratio, 3.91; 95% CI, 2.93-5.22), compared with those who were non-frail and had no respiratory impairment.ConclusionFrailty and respiratory impairment are strongly associated with one another and substantially increase the risk of death when both are present. Establishing these associations may inform interventions designed to reverse or prevent the progression of either condition and to reduce adverse outcomes.     

The impact of platelet transfusion characteristics on posttransfusion platelet increments and clinical bleeding in patients with hypoproliferative thrombocytopenia

Platelet characteristics, such as platelet dose, platelet source (apheresis vs pooled), platelet donor-recipient ABO compatibility, and duration of platelet storage, can affect posttransfusion platelet increments, but it is unclear whether these factors impact platelet transfusion efficacy on clinical bleeding. We performed secondary analyses of platelet transfusions given in the prospective randomized Platelet Dose Study, which included 1272 platelet-transfused hematology-oncology patients who received 6031 prophylactic platelet transfusions. The primary outcome of these analyses was time from first transfusion to first World Health Organization ≥ grade 2 bleeding. Platelet transfusion increments were assessed at 0.25 to 4 hours and 16 to 32 hours after platelet transfusion. There were 778 patients evaluable for analysis of time to bleeding. Adjusted models showed that randomized dose strategy, platelet source, ABO compatibility, and duration of storage did not predict this outcome. Platelet increments were generally higher for transfusions of apheresis platelets, ABO-identical platelets, and platelets stored 3 days versus 4 to 5 days. Thus, although platelet source, ABO compatibility, and duration of storage exert a modest impact on both absolute and corrected posttransfusion platelet increments, they have no measurable impact on prevention of clinical bleeding. This trial was registered at www.clinicaltrials.gov as #NCT00128713.     

Impact of Comorbidity on Mortality Among Older Persons with Advanced Heart Failure

BACKGROUND  

Care for patients with advanced heart failure (HF) has traditionally focused on managing HF alone; however, little is known about the prevalence and contribution of comorbidity to mortality among this population. We compared the impact of comorbidity on mortality in older adults with HF with high mortality risk and those with lower mortality risk, as defined by presence or absence of a prior hospitalization for HF, respectively.     

Exudative hemorrhagic retinopathy related to all-trans retinoic acid differentiation syndrome in a patient with acute promyelocytic leukemia

Dear Editor,We report a case of significant exudative hemorrhagic retinopathy attributed to differentiation syndrome(DS).DS is a systemic inflammatory condition seen in patients with acute promyelocytic leukemia(APML)undergoing treatment with all-trans retinoic acid(ATRA).DS can lead to endothelial injury and capillary leakage throughout the body.Treatment with corticosteroids during chemotherapy has been shown to reduce the risk of developing DS[1-2].There are limited reports of the ocular manifestations of DS in the literature,including pale yellow choroidal lesions,scattered retinal hemorrhages,and serous retinal detachments[3-5].