Neutralizing antibody to polioviruses in normal human urine

Urinary immunoglobulins in viral diagnosis: An overview

Antibody detection by serological methods gained a lot of interest in recent years and has become the backbone of virological diagnosis. Despite the detection of all five classes of immunoglobulins in urine, not much attention has been paid to the use of urine as a diagnostic sample to detect viral antibodies. Unlike venipuncture, this non-invasive mode of sample collection can help cover all age groups, especially paediatric and old age patients, where blood collection is difficult. Using urine as a sample is also economical and involves lesser risk in sample collection. The antibodies are found to be stable in urine at room temperature for a prolonged period, which makes the sample transport management easier as well. A few recent studies, have also shown that the detection limit of antibodies in urine is at par with serum or other clinical material. So, the ease in sample collection, availability of samples in large quantity and stability of immunoglobulins in urine for prolonged periods can make urine an ideal sample for viral diagnosis.

Evaluation of urine as a clinical specimen for diagnosis of hepatitis a

The present study pertains to the evaluation of urine as a specimen for detection of anti-hepatitis A virus (anti-HAV) antibodies. Immunoglobulin M (IgM), IgG, and IgA capture enzyme-linked immunosorbent assays for hepatitis A were performed on paired serum and urine specimens collected from hepatitis A patients (n = 92), healthy individuals (n = 100), non-A hepatitis patients (n = 70), and patients with nonhepatic diseases (n = 64, including 37 renal disease patients). Hepatitis A patients seropositive for anti-HAV IgM showed 95.65% uropositivity. No false-positive reactions were observed in control groups. The uropositivity of anti-HAV IgM persisted during the convalescent phase of the disease. Anti-HAV IgG uropositivity correlated well with corresponding seropositivity in all groups (P > 0.05 for each). No significant difference between the proportions of serum and urine positivity for anti-HAV IgA was noted (P > 0.05 for each). Using seroreactivity as a "gold standard," the sensitivity and specificity for anti-HAV IgM, anti-HAV IgG, and anti-HAV IgA tests with urine as a specimen were found to be 95.65 and 100%, 97.76 and 76.47%, and 92.23 and 88.18%, respectively. Urine appears to be comparable to serum for diagnosis of recent and past infection with hepatitis A.

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.

Urine-based diagnostic technologies

The worldwide dissemination of infectious agents has created a demand for simple diagnostic tests. Urine-based testing makes use of non-invasive collection of specimens, and there is no need for expensive facilities and equipment, or for highly trained personnel. As urine antibodies retain activity under normal conditions of transport and storage, such tests appear to have widespread application. Urine-based antibody tests have also indicated a compartmentalized antibody response to HIV-1 infection. Urine studies suggest that antibodies to the products of endogenous viral genes may be involved in the pathogenesis of chronic diseases of suspected viral etiology.

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.

Antibodies to human immunodeficiency virus type 1 in the urine specimens of HIV-1-seropositive individuals

Specific antibodies to human immunodeficiency virus type 1 (HIV-1) were detected in 200-fold concentrated urine samples, but none were detected in unconcentrated urine specimens, from 100 randomly selected HIV-1--seropositive individuals by enzyme-linked immunosorbent assay (ELISA) and Western blot techniques using the manufacturer's recommended procedures. Using modified methods for both the ELISA and Western blot tests, antibodies to HIV-1 have also been detected in the unconcentrated urine specimens from the same HIV-1--seropositive individuals. No difference in the frequency of antibodies to HIV-1 were found between unconcentrated and 200-fold concentrated urine samples when tested by the modified methods. HIV-1 core antigen (p24) was not detected in either the concentrated or the unconcentrated HIV-1--seropositive adult urine samples; none of these individuals showed overt clinical or laboratory evidence of renal dysfunction. The titer of the antibodies to HIV-1 found in the urine specimens was found to be parallel with the titer of antibodies to HIV-1 in the corresponding individual's serum. Further elucidation of the pathophysiology and the nature of the specific antibodies to HIV-1 observed in the urine of HIV-1--seropositive individuals is under investigation in our laboratories.

Urinary immunoglobulins in healthy individuals and children with acute pyelonephritis

Urine samples obtained from children with acute pyelonephritis and from healthy children and adults were analysed with regard to the molecular form and specific antibody activity of urinary immunoglobulins. The urinary IgA and IgG levels were quantified in unconcentrated urine by radioimmunoassay. The children with urinary tract infection had significantly higher levels of IgG and IgA than age-matched controls but not higher than healthy adults. After tenfold concentration, the urine was fractionated on an Ultrogel AcA 22 column, and the IgA, secretory IgA, and IgG in the fractions were determined by radioimmunoassay. IgA in urine from healthy adults was predominantly represented by polymeric IgA linked to secretory component; small quantities of monomeric IgA were also present. IgG eluted in the position of the serum standard. Increased proportions of IgG and monomeric IgA were found in the infected patients. Specific antibody activity of the IgG and IgA classes to antigens of the infecting Escherichia coli strain was detected in whole and in fractionated urine from children with acute pyelonephritis. The specific antibody activity in healthy adults and children was low.

Antibodies in urine of chimpanzees with chronic adenoviral viruria

Many chimpanzees have naturally occurring chronic intermittent viruria with an adenovirus of a new type called Pan 11. Small amounts of neutralizing antibodies to Pan 11 adenovirus were found in the urine of chimpanzees. Urinary antibodies to adenovirus were mainly of the immunoglobulin G (IgG) class with some IgA antibodies also present. There was no neutralizing activity in urine against another adenovirus, Pan 9, which has been isolated from lymph nodes, but not from urine, of chimpanzees; however, sera of all chimpanzees had neutralizing antibodies to Pan 9 virus, some with titers similar to those of antibodies against Pan 11 virus. Antibodies reacting with simian cytomegalovirus by indirect immunofluorescence were found in sera of all chimpanzees tested and in two of six urines. There was no correlation between levels of antiviral IgG antibodies in serum and urine by immunofluorescence. These findings suggest that both IgG and IgA antibodies may be locally produced in response to viral infection of the urinary tract in primates.

Occurrence of BK virus and BK virus-specific antibodies in the urine of patients receiving chemotherapy for malignancy

Urine specimens from 23 children and 9 adults who were undergoing treatment for malignancy as well as urines from 40 normal individuals were concentrated and examined for evidence of papovavirus infection. Papovavirus particles were detected in 6 of 64 urines examined by electron microscopy. Three of the particle-positive urines induced BK virus-specific immunofluorescence after inoculation of WI38 cells, and three isolations of BK virus were made by inoculation of urines from virus-excreting patients into Vero cells. BK virus-specific hemagglutination-inhibiting and immunofluorescence neutralizing antibodies were found in a majority of urines from adult patients, in about a fifth of pediatric patients, and less often in normal urines. Urines of virus-excreting patients generally had antibodies. In indirect fluorescent antibody tests, BK virus-specific antibodies of the immunoglobulin G class were found in five urine specimens from patients; immunoglobulin A antibodies were not detected in any urine. These data suggest that activation of BK virus is related to immunosuppression and not to transplantation itself and that the occurrence of virus-specific antibodies in urine may be indicative of virus multiplication in the urinary tract.

ON THE SENSITIZING PROPERTIES OF SOME NORMAL AND PATHOLOGIC HUMAN IMMUNE GLOBULINS AND FRAGMENTS OBTAINED BY PAPAIN OF PEPSIN DIGESTION

Although normal γ₁A (β₂A) globulins, myeloma proteins, as well as Bence-Jones proteins and normal human urine γ globulins cross-react with 7S γ globulins, none of these proteins can sensitize the skin of the guinea-pig to give a reverse passive cutaneous anaphylaxis reaction. The 3.5S fragments of human antisera to horse serum proteins can no longer give passive cutaneous anaphylaxis reactions, but fragment C and probably A can inhibit the passive cutaneous anaphylaxis reaction of the original antiserum. By reverse passive cutaneous anaphylaxis, negative results were obtained with each of the three fragments or the 5S pepsin digest.