Evidence for the transmission of parvovirus B19 in patients with bleeding disorders treated with plasma‐derived factor concentrates in the era of nucleic acid test screening

BACKGROUND: Parvovirus B19 (B19V) is a small, nonenveloped virus that typically causes a benign flu‐like illness that occurs most frequently in childhood. The virus is resistant to current viral inactivation steps used in the manufacture of antihemophilic factor concentrates and B19V transmission through these products has been documented. Since 2000, B19V nucleic acid test (NAT) screening of plasma pools has been implemented to further decrease the viral burden in these products, but no study has examined populations using these products to assess the impact of the screening on B19V transmission. STUDY DESIGN AND METHODS: Blood specimens obtained from participants of a surveillance system established in federally supported specialized bleeding disorders clinics were used in a B19V seroprevalence study. RESULTS: A total of 1643 specimens from 1043 participants age 2 to 7 years born after B19V NAT screening was implemented were tested. Age‐specific prevalence rates were generally higher for subjects exposed to either plasma‐derived products alone or in combination with other products compared to subjects with no exposure to antihemophilic products. Overall, compared to participants unexposed to blood or blood products, those exposed to plasma‐derived products alone were 1.7 times more likely to have antibodies to B19V (p = 0.002). CONCLUSION: These results are consistent with continued B19V transmission through plasma‐derived factor concentrates. Effective viral inactivation and detection processes are needed to protect users of these products from infection with B19V or other new or emerging viruses.     

Hepatitis B infection in patients with acute liver failure in the United States

Occult hepatitis B virus (HBV) infection has been reported in 30% to 50% of patients with acute liver failure (ALF) in small case series. The aim of this study was to determine the prevalence of occult HBV infection in a large series of ALF patients in the United States and the prevalence of precore and core promoter variants in patients with ALF caused by hepatitis B. Sera from patients in the US ALF study and liver, when available, were tested using nested polymerase chain reaction (PCR) with primers in the HBV S and precore regions. PCR-positive samples were sequenced. Sera and/or liver from 139 patients (39 males, 100 females; mean age, 42 years) enrolled between January 1998 and December 1999 were studied. Twelve patients were diagnosed with hepatitis B, 1 with hepatitis B+C+D coinfection, and 22 had indeterminate etiology. HBV DNA was detected in the sera of 9 (6%) patients; all 9 had ALF caused by hepatitis B. HBV genotypes A, B, C, and D were present in 4, 3, 1, and 1 patients, respectively. Seven of these 9 patients had precore and/or core promoter variants. Liver from 19 patients were examined. HBV DNA was detected in the liver of 3 patients with ALF caused by hepatitis B, but in none of the remaining 16 patients with non-B ALF. Contrary to earlier reports, occult HBV infection was not present in this large series of ALF patients in the United States. HBV precore and/or core promoter variants were common among US patients with ALF caused by hepatitis B.     

Guidelines for colonoscopy surveillance after polypectomy: a consensus update by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society

Adenomatous polyps are the most common neoplastic findings discovered in people who undergo colorectal screening or who have a diagnostic work-up for symptoms. It was common practice in the 1970s for these patients to have annual follow-up surveillance examinations to detect additional new adenomas and missed synchronous adenomas. As a result of the National Polyp Study report in 1993, which showed clearly in a randomized design that the first postpolypectomy examination could be deferred for 3 years, guidelines published by a gastrointestinal consortium in 1997 recommended that the first follow-up surveillance take place 3 years after polypectomy for most patients. In 2003 these guidelines were updated and colonoscopy was recommended as the only follow-up examination, stratification at baseline into low risk and higher risk for subsequent adenomas was suggested. The 1997 and 2003 guidelines dealt with both screening and surveillance. However, it has become increasingly clear that postpolypectomy surveillance is now a large part of endoscopic practice, draining resources from screening and diagnosis. In addition, surveys have shown that a large proportion of endoscopists are conducting surveillance examinations at shorter intervals than recommended in the guidelines. In the present report, a careful analytic approach was designed to address all evidence available in the literature to delineate predictors of advanced pathology, both cancer and advanced adenomas, so that patients can be stratified more definitely at their baseline colonoscopy into those at lower risk or increased risk for a subsequent advanced neoplasia. People at increased risk have either 3 or more adenomas, high-grade dysplasia, villous features, or an adenoma 1 cm or larger in size. It is recommended that they have a 3-year follow-up colonoscopy. People at lower risk who have 1 or 2 small (<1 cm) tubular adenomas with no high-grade dysplasia can have a follow-up evaluation in 5-10 years, whereas people with hyperplastic polyps only should have a 10-year follow-up evaluation, as for average-risk people. There have been recent studies that have reported a significant number of missed cancers by colonoscopy. However, high-quality baseline colonoscopy with excellent patient preparation and adequate withdrawal time should minimize this and reduce clinicians concerns. These guidelines were developed jointly by the US Multi-Society Task Force on Colorectal Cancer and the American Cancer Society to provide a broader consensus and thereby increase the use of the recommendations by endoscopists. The adoption of these guidelines nationally can have a dramatic impact on shifting available resources from intensive surveillance to screening. It has been shown that the first screening colonoscopy and polypectomy produces the greatest effects on reducing the incidence of colorectal cancer in patients with adenomatous polyps.     

Fulminant hepatitis A virus infection in the United States: Incidence, prognosis, and outcomes

Acute liver failure (ALF) due to hepatitis A virus (HAV) infection is an uncommon but potentially lethal illness. The aim of this study was to identify readily available laboratory and clinical features associated with a poor prognosis among ALF patients with HAV infection. The presenting features of 29 adults with anti-HAV IgM positive ALF enrolled in the ALFSG_between 1998 and 2005 were reviewed. The HAV patients listed for transplantation by UNOS were also reviewed. Acute HAV accounted for 3.1% of patients enrolled in the ALFSG. At 3 weeks follow-up, 16 had spontaneously recovered (55%), 9 underwent transplantation (31%), and 4 had died (14%). A prognostic model incorporating 4 presenting features (serum ALT <2,600 IU/L, creatinine >2.0 mg/dL, intubation, pressors) had an AUROC for transplant/death of 0.899 which was significantly better than the King's College criteria (0.623, P = .018) and MELD scores (0.707, P = .0503). Between 1988 and 2005, the frequency of patients requiring liver transplantation for HAV in the UNOS database significantly decreased from 0.7 % to 0.1% (P < .001). In addition, the proportion of HAV cases enrolled in the ALFSG significantly decreased from 5% to 0.8% (P = .007). In conclusion, the frequency of HAV patients enrolling in the ALFSG and being listed for liver transplantation in the United States has declined in parallel. A prognostic index consisting of 4 clinical and laboratory features predicted the likelihood of transplant/death significantly better than other published models suggesting that disease specific prognostic models may be of value in non-acetaminophen ALF.     

The Pregnant Smoker: Nursing Implications

Evidence documents that smoking is especially detrimental to the unborn fetus and to the developing child. The reproductive risks associated with smoking are reviewed, and implications for nurses caring for the pregnant smoker are discussed. Strategies to assist patient smoking cessation efforts are outlined. Nurses must consider cigarette smoking in pregnancy to be as serious a risk factor to maternal and infant health as drugs and infectious diseases.     

侵袭性NK细胞白血病的临床研究--附九例报告

目的提高对侵袭性NK细胞白血病(ANKL)的认识,对其诊断标准进行总结。方法回顾性分析临床病例。结果和结论ANKL患者常有发热、肝脾肿大、黄疸、肝功能异常和全血细胞减少,疾病进展迅速,短期内出现多脏器功能衰竭、噬血细胞综合征,中位生存期小于2个月。目前较公认的诊断标准:①常有发热及肝、脾、淋巴结肿大;②外周血可以有中性粒细胞减少、贫血和血小板减少,淋巴细胞比例增高,大颗粒淋巴细胞可以增多,但不是诊断的必要条件;③骨髓涂片和活检均可见较多的大颗粒淋巴细胞浸润;④细胞免疫表型为CD2( ),表面CD3(-),胞质CD3( ),CD56( ), CD57(-),CD11b和CD16可以阳性,无T细胞受体重排;⑤有EB病毒抗体阳性的证据;⑥没有特异的染色体异常,较多见的核型异常为de1(6)(q21q25);⑦排除其他引起大颗粒淋巴细胞增多的疾病。