Hepatitis E antibody profiles in serum and urine.

The aim of this study was to evaluate anti-HEV antibody profiles in urine specimens in comparison to corresponding serum samples to assess the utility of urine as a clinical specimen. Paired serum and urine specimens from 71 hepatitis E patients, 33 non-E hepatitis patients, 63 patients with nonhepatic diseases, and 26 healthy individuals were tested by recombinant HEV protein (55 kD)-based indirect enzyme-linked immunosorbent assay (ELISA). Uronegativity for anti-HEV IgM was noted in 71 (100%) serologically confirmed patients with hepatitis E. Hepatitis E patients (10/10) showed urinary absence or very low levels of total IgM by capture ELISA, suggesting absence or low levels of filtration, and/or local synthesis, and/or transudation of IgM in urine during infection. When these patients were tested for total IgG and IgA, microquantities of immunoglobulins were noted in all urine samples (10/10 for each). However, the proportions of uropositivity for anti-HEV IgG and IgA in hepatitis E patients were low and indicated only 21.42% and 49.33% concordance with seropositivity, respectively. Control groups also showed low and variable uropositivity for anti-HEV IgG and IgA. Overall, HEV-specific antibodies exhibited by serum in recent and past infections were not found in urine. The study demonstrated the inadequacy of urine specimens for detection of hepatitis E antibodies.

Application of commercial assays to detect IgG antibodies to hepatitis C virus in urine: a pilot study from autopsy cases.

Hepatitis C virus (HCV), the main cause of non-A, non-B hepatitis in the United States and possibly in the world, is believed to be transmitted primarily through parenteral exposure. Many screening and supplemental tests are available to detect antibodies to HCV in serum. The ability to use commercial assays to detect antibodies to HCV in urine was investigated in this study. A total of 229 serum/urine matched samples were collected sequentially from forensic autopsy cases examined at the Office of the Chief Medical Examiner, State of Maryland. Testing was performed using the Ortho, Innogenetics, and Abbott second generation HCV screening tests and the INNO-LIA HCV Ab supplemental assay. Sample volumes were increased for urine testing. Forty-six of 229 serum samples were positive by screening and confirmed by supplemental tests. The urine samples produced positive results on 44-45 of the same 46 by screening tests and all 46 positives by the supplemental test. There were no false positive samples using urine when compared with the serum pairs. The one false negative sample using urine was still nonreactive when the urine volume was increased to 200 microliters using the screening tests. Generally, five times the serum volume was required for the screening tests to be optimal for urine samples. The urine samples were stored under different conditions prior to testing to determine the influence on antibody stability in urine.

Reliability of immunoassays for anti-HCV antibodies (ELISA and RIBA II) in patients with essential mixed cryoglobulinemia (EMC).

The recent reports of a very high frequency of signs of hepatitis C virus (HCV) infection among patients with essential mixed cryoglobulins (EMC) suggest new hypotheses for the pathogenesis of this disease. However, most of these studies have been seriously criticized. The serologic test designed for detection of anti-HCV antibodies (ELISA, RIBA I and II) may yield a significant rate of false-positive results when performed on cryoglobulinemic sera, and the detection of the HCV genome by PCR is still heavily conditioned by practical problems. Indirect, but possibly more reliable, evidence of HCV infection in cryoglobulinemic patients might come from the demonstration of anti-HCV antibodies by a conventional technique (ELISA or RIBA) in the purified polyclonal non-rheumatoid immunoglobulinemic fraction excreted in the urine by glomerular filtration. Fifty-two patients whose serum had tested positive for HCV antibodies (by ELISA and RIBA) on multiple occasions were enrolled in this study. They were diagnosed as having either EMC or HCV chronic hepatitis without cryoglobulinemia at least one year ago. The urine samples of these patients were tested for anti-HCV antibodies by ELISA and RIBA. In patients with chronic C hepatitis the antibodies most frequently found in the serum were anti-C33c and anti-C22-3. The results of the RIBA were substantially confirmed by ELISA, with a positive test in the urine of 30 of 32 seropositive patients. Similar results were obtained in patients with EMC II. We conclude that the specificity of the RIBA and ELISA tests for HCV antibodies in patients with EMC appears to be as high as in HCV+ patients without serum cryoglobulins. EMC patients have a high incidence of HCV infection and active chronic liver disease.

The detection in urine specimens of IgG and IgM antibodies to hepatitis A and hepatitis B core antigens.

The use of urine as a noninvasive specimen for the diagnosis of hepatitis A (HAV) and hepatitis B (HBV) virus infections was investigated. Specimens of urine were collected at the same time as blood or saliva specimens, or singly in cases of previously serologically confirmed recent infection. The specimens were tested for IgG and IgM anti-HAV and anti-HBc by immunoglobulin class-specific capture radioimmunoassays (GACRIA and MACRIA). On the basis of assays on urine specimens it was possible to distinguish between individuals who were susceptible or immune to HAV or who had recently been infected with HAV. Using assays on 327 corresponding saliva specimens as reference tests, the observed sensitivity and specificity of tests on urine specimens by anti-HAV GACRIA were 98.9% and 99.1%, respectively, and by anti-HAV MACRIA were 95.8% and 99.6%, respectively. IgM and IgG anti-HBc were detected readily in the urine of 35 acute or recent cases of hepatitis B but were not found in the urine of seronegative individuals. Of the urine specimens from 52 individuals who were HBsAg carriers or who had had long past HBV infections, 49 contained detectable IgG anti-HBc. Of urine specimens from 42 HBsAg carriers, 11 contained raised IgM anti-HBc levels. Urine, which is a convenient specimen to collect, can be used to study outbreaks of hepatitis A, to ascertain the HAV immune status of individuals, to differentiate hepatitis A from hepatitis B, and to identify individuals who have been naturally exposed to HBV.