Nonculture laboratory methods for the diagnosis of infectious endocarditis

Over the past few years new techniques have been developed to improve the diagnosis of infectious diseases. However, despite the various available culture systems, culture-negative endocarditis currently represents a challenge for physicians. In our laboratory, in an effort to reduce the rate of endocarditis of unknown etiology, we have used several recent histologic, serologic, and molecular tests. We review the latest technical developments for the diagnosis of infectious endocarditis, including those that we are currently using.     

Nonculture laboratory methods for the diagnosis of infectious endocarditis

Over the past few years new techniques have been developed to improve the diagnosis of infectious diseases. However, despite the various available culture systems, culture-negative endocarditis currently represents a challenge for physicians. In our laboratory, in an effort to reduce the rate of endocarditis of unknown etiology, we have used several recent histologic, serologic, and molecular tests. We review the latest technical developments for the diagnosis of infectious endocarditis, including those that we are currently using.     

Informative value of methods for laboratory diagnosis of Giardia infection

The author assesses the informative value of two methods of laboratory diagnosis of L. intestinalis: serological assay using indirect immunofluorescence versus fecal Giardia antigen test using the immunochromatographic RIDA Quick Giardia test system. The results of these procedures were compared with those of fecal microscopy. The serological approach to diagnosing Giardia infection was found to be of low informative value. There is evidence suggesting the high specificity and sensitivity of detection of Giardia antibody in the feces, which allows it to be recommended in parasitological laboratory. It has been established that fecal prestorage in the Turdyev preservative can reduce the sensitivity of the RIDA Quick Giardia test system at the low concentration of parasitic cysts in the material being examined.     

新型冠状病毒肺炎实验室诊断方法及意义

新型冠状病毒肺炎(COVID-19)正在全球范围内流行,已造成大量死亡,严重威胁公共卫生安全。作为一种全新的高传染性疾病,对其认识需不断探索与完善。目前尚无特效药物,疫情管控依赖于早期准确的诊断与严格的隔离措施。因此,实验室检测方法的优化及准确性成为疫情防控极大的挑战。《新型冠状病毒肺炎诊疗方案(试行第八版)》规定,病...     

基于结核病宿主免疫反应的实验室检测技术及其临床应用

结核分枝杆菌是引起人类结核病的病原体。作为胞内致病菌,结核分枝杆菌与宿主免疫系统的相互作用决定了疾病发生、发展及患者的治疗转归,因此宿主对结核分枝杆菌的免疫应答具有作为结核病早期诊断及治疗预后判断的潜在价值。特别是在目前病原学诊断技术存在诸多弊端的情况下,如何利用宿主的免疫学指标反映疾病的状态是结核病实验室诊断的重要领域。作者主要从基于结核病宿主免疫反应的临床检测技术为切入点,系统回顾了近年来本领域的基础研究热点和临床应用实例,为早期精准诊断结核病提供重要的新思路。     

弓形虫病的分子诊断

近年来,弓形虫病分子诊断技术发展较快,本文介绍核酸分子杂交、聚合酶链反应（PCR）常用的弓形虫基因序列,以及常规PCR、巢式PCR、实时定量PCR、免疫PCR、原位PCR、环介导等温扩增等分子生物学技术在弓形虫病诊断中的研究与应用。     

IgA nephropathy. Use of modern laboratory methods and renal biopsy for diagnosis

IgA nephropathy is the most frequent primary glomerulonephritis worldwide. At its onset, the most common laboratory sign is isolated haematuria often accompanied with mild proteinuria (up to 1.5 g/24 h). The disease displays a progressive course with end-stage renal disease occurring in up to half of patients 20 years after onset. Diagnosis is established by immunofluorescent microscopy of a renal biopsy specimen. Discoveries in the past decade on the pathogenesis of IgA nephropathy together with complex evaluation of its clinical presentation enable to establish diagnosis with a satisfactory degree of probability even without biopsy. IgA nephropathy patients display increased or borderline serum IgA levels; increased serum levels of IgA fraction with degalactosylated O-linked side sugar chains; increased serum levels of anti-N-acetylgalactosamine antibodies; increased levels of circulating immune complexes composed of IgA1 complexed with IgG or IgA1; increased serum levels of circulating complexes composed of IgA and fibronectin; and frequent occurrence of the rheumatoid IgA factor. Clinical use of these still generally unavailable methods would reduce the renal biopsy indication in patients with isolated or predominant haematuria.     

Primary biliary cirrhosis: Clinical and laboratory criteria for its diagnosis

Primary biliary cirrhosis(PBC) is a chronic progressive cholestatic granulomatous, and destructive inflammatory lesion of small intralobular and septal bile ducts, which is likely to be caused by an autoimmune mechanism with a the presence of serum antimitochondrial antibodies and a potential tendency to progress to cirrhosis. Despite the fact that the etiology of this disease has beenunknown so far, there has been a considerable body of scientific evidence that can reveal the clinical and laboratory signs of PBC and the individual components of its pathogenesis and elaborate diagnostic criteria for the disease and its symptomatic therapy. Deficiencies in autoimmune tolerance are critical factors for the initiation and perpetuation of the disease. The purpose of this review is to summarize the data available in the literature and the author's findings on clinical and laboratory criteria for the diagnosis of PBC. This review describes the major clinical manifestations of the disease and the mechanisms of its development. It presents the immunological, biochemical, and morphological signs of PBC and their significance for its diagnosis. A great deal of novel scientific evidence for the problem of PBC has been accumulated. However, the inadequate efficiency of therapy for the disease lends impetus to the quest for its etiological factors and to further investigations of its pathogenetic mechanisms and, on this basis, to searches for new methods for its early diagnosis.     

IgA antibodies for diagnosis of acute congenital and acquired toxoplasmosis

An ELISA for IgA toxoplasma antibodies was positive in 12 pregnant women who seroconverted during gestation. Positive IgA titers were also noted in 10 individuals with biopsy-proven toxoplasmic lymphadenitis; the highest titers were noted in the first months following onset of clinical signs. Toxoplasma IgA antibodies were also demonstrable in 8 of 9 infants/fetuses with congenital toxoplasma infection. In some, IgM antibodies could not be demonstrated. Among 20 patients with AIDS and biopsy-proven toxoplasmic encephalitis, only 1 had IgA antibodies. None of 20 individuals with chronic toxoplasma infection had demonstrable IgA antibodies. Demonstration of IgA toxoplasma antibodies should be useful for diagnosis of recently acquired infection and for diagnosis of the infection in the fetus and newborn.