György Ábel

Current status and future prospects of point-of-care testing around the globe

In the past half-century, routine central laboratory testing has become increasingly automated and efficient. The majority of clinical chemistry, immunochemistry and hematology testing are performed using high throughput instrumentation, with sophisticated automation. Microbiology, immunohematology and molecular diagnostic testing are also becoming increasingly automated. Recent challenges in healthcare demand new diagnostic solutions worldwide. Point-of-care testing (POCT) offers considerable advantages over central laboratory testing, such as fast and simple specimen handling, and simpler sample requirement (no additives and mostly blood from finger stick; and urine). No transportation is required, and POCT delivers short turnaround time of approximately 5–15 min. In recent years, POCT has gained ground worldwide. In advanced healthcare systems, POCT may be beneficial if health or cost–benefits can be established. In resource-poor countries, POCT may be the only means of delivering advanced testing for epidemiologically important diseases, such as tuberculosis of HIV infection.

A competitive reverse transcription-polymerase chain reaction assay for quantitation of GB virus C/hepatitis G virus RNA that circumvents heteroduplex artifact.

The role of GB virus C (GBV-C)/hepatitis G virus (HGV) in hepatitis has been controversial. To investigate its possible pathogenicity and site(s) of replication, it is important to develop an accurate quantitative assay for both positive and negative strand GBV-C/HGV RNA. In this study, a competitive reverse transcription-polymerase chain reaction (RT-PCR) assay for both positive and negative strand GBV-C/HGV RNA quantitation was developed. In developing the quantitative assay, heteroduplex formation was repeatedly observed. A heterologous competitor RNA with GBV-C/HGV primer-binding sequences was introduced, and heteroduplex artifact was circumvented successfully. Two-hundred thirty-seven serum specimens were screened by RT-PCR for GBV-C/HGV RNA. Two of the 62 patients infected with chronic hepatitis C virus (HCV) were found to be positive for GBV-C/HGV RNA. None of the 50 other patients with no evidence of HCV infection and none of the 125 normal individuals were positive for GBV-C/HGV RNA. The sensitivity of RT-PCR was 3000 gE/ml (30 gE in RT-PCR). Alternate methods for residual DNA removal and its detection in synthetic RNA were introduced. A RT control containing no primer before PCR is necessary to evaluate the trace amounts of template DNA remaining in synthesized RNA. The method will differentiate reliably between positive and negative strand RNAs up to a 10(4)-fold difference in titer. The positive and negative strand GBV-C/HGV RNAs were detected in one patient by RT-PCR and hybridization analysis, and the strand titer was determined by RT-PCR.

6 – COMPLEMENT DEFICIENCY AND SYSTEMIC LUPUS ERYTHEMATOSUS

The exact etiology of systemic lupus erythematosus (SLE) is not known. Hereditary complement deficiency, especially deficiency of an early complement component of the classical pathway, is a genetic factor associated with SLE and SLE-like disease in humans and most recently in mouse models with “knockout” of these components. This chapter reviews the association of hereditary and acquired complement deficiency states with SLE and SLE-like disease. The emphasis is on clinical manifestations in patients with these deficiencies, the differences in many patients from classic SLE, and the implication of these differences for current hypotheses on the specific role of the early complement components in SLE. The discussion begins with a description of the complement system. Next, the biological activities and the associations of deficiencies of the complement system with disease are described to provide the context for this review on the early components. The genetics of complement components and the clinical manifestations of genetic and acquired complement deficiencies are then reviewed with the exception of the genetics of the C4 component of complement. The chapter concludes with a speculative discussion of the role of complement deficiency in SLE, including recent studies and hypotheses on the role of early complement components in apoptosis.

Observations on Cryoglobulin Testing: II. The Association of Oligoclonal Mixed Cryoglobulinemia with Cirrhosis in Patients Infected with Hepatitis C Virus

Objective. To determine whether a mixed cryoglobulin type correlated with cirrhosis in patients infected with hepatitis C virus (HCV). Methods. We investigated the results of mixed cryoglobulin tests performed in the clinical laboratory on patients with and without HCV infection. Results. A higher prevalence of oligoclonal cryoglobulins designated Type IIa was present in HCV-infected patients with cirrhosis than in those without cirrhosis. Conclusion. An association of Type IIa cryoglobulins with cirrhosis in HCV-infected patients has not previously been reported.

Cryoglobulins Secondary to Hepatitis C Virus Infection

Publisher Summary This chapter discusses the cryoglobulins secondary to hepatitis C virus (HCV) infection. There are two types of mixed cryoglobulins: type II contains polyclonal immunoglobulin (IgG) and a monoclonal IgM rheumatoid factors (mRF), while in type III both the IgG and IgM RF are polyclonal. The manifestations of the disease range from a benign cutaneous vasculitis to life-threatening severe vasculitis of vital organs. The high frequency of hepatocellular pathology in patients with essential mixed cryoglobulinemia suggested the involvement of hepatotropic viruses in the pathogenesis of the disease.