Indirect Latex Agglutination Test Research Articles

Seropositivity rates for Bartonella henselae, Toxocara canis and Toxoplasma gondii in New Zealand blood donors

Bartonella henselae, Toxocara canis and Toxoplasma gondii organisms can all cause vision-threatening posterior segment disease. Diagnosis relies heavily on clinical findings, but detection of antibodies in the patient's serum may be helpful in some cases. The significance of a positive serology result depends on the seroprevalence in the general population. Seroprevalence rates for these organisms vary widely around the world and this study aimed to determine the rates for a New Zealand population. One hundred and forty healthy blood donors from the Waikato region in the North Island of New Zealand had their serum tested using an indirect latex agglutination test for detection of T. gondii antibodies, an indirect immunofluorescent assay for B. henselae antibodies and an enzyme-linked immunosorbent assay test for T. canis antibodies. Seropositivity rates for T. canis, T. gondii and B. henselae in this New Zealand population were 0.7 +/- 1.65%, 42.9 +/- 8.12% and 5 +/- 3.61%, respectively. Seropositivity rates for T. gondii and B. henselae in New Zealand are similar to rates reported in some other countries; however, T. canis seroprevalence may be lower than reported elsewhere in the world.

トキソプラズマ性リンパ節炎例

Toxoplasma gondii is a protozoan parasite that infects up to a fourth of the Japanese population. Infection is mainly acquired by ingestion of food or water that is contaminated with oocysts shed by cats or by eating undercooked or raw meat containing tissue cysts. Toxoplasma gondii primary infection is asymptomatic in most patients. The most typical clinical manifestation is isolated cervical lymphadenopathy.We report a case of chronic right neck lymphadenopathy caused by infection with toxoplasma gondii. A 16-year-old previously healthy male visited our department for evaluation of chronic cervical lymphadenopathy. Physical examination revealed multiple painless lymph nodes with a size of approximately 1.5cm in the right submandibular region. The first histological examination revealed stellate granulomas with central necrosis, which is compatible with cat scratch disease (CSD). Sixteen months later, submandibular lymphadenopathy appeared again. The second histological examination was probable toxoplasmosis, which was confirmed with serological tests. Immunoglobulin (Ig) M and IgG antibodies to toxoplasma gondii were detected, which revealed elevated titers of both IgM and IgG, of 20 and 1, 280, respectively. Both of dye test and indirect latex agglutination test for toxoplasma gondii were 1, 024, respectively. The patient was thought to be infected with toxoplasma gondii following CSD. He was successfully treated with Acetylspiramycin (900mg/day) for four weeks without any evidence of recurrence, or side effect.

Western blot analysis of stray cat sera against Toxoplasma gondii and the diagnostic availability of monoclonal antibodies in sandwich-ELISA.

A total of 198 sera from stray cats was assayed against Toxoplasma gondii antigen by western blot. Out of 198 sera assayed, 26 sera (13.1%) showed typical blot patterns against T. gondii. When spotted by ELISA absorbance and indirect latex agglutination test (ILAT) titer, all 26 cases were distributed over the cut-off value of ELISA whereas 24 cases (92.3%) were in the positive range of 1:32 or higher and 2 cases in negative range by ILAT. Among western blot negative 172 sera, 162 cases were negative in both ILAT and ELISA while 10 cases were reactive falsely such that three cases were ILAT positive with 1:32 titer and 9 cases were ELISA positive (2 cases overlapped). These 10 cases reacted peculiarly without typical binding pattern in Western blot. Sandwich-ELISA was performed with monoclonal antibodies (mAbs) of Tg563 (30 kDa, SAG1), Tg505 (22 kDa, SAG2), Tg605 (43 kDa, SAG3), Tg556 (28 kDa. GRA2), Tg737 (32 kDa, GRA6), Tg695 (66 kDa, ROP2), Tg786 (42 kDa, ROP6), and Tg621 (32 kDa, anonymous but cytosolic) clone, respectively. All western blot-positive cases were in the positive range and negative cases in the negative range clearly. Among the 10 false reactive cases, 3 cases were in the positive range with one or more mAbs. All mAbs used in this study were confirmed to be specific to T. gondii infection as a standardized sandwich-ELISA to differentiate it from other pathogens.

Detection of antibodies in serum and cerebrospinal fluid to Toxoplasma gondii by indirect latex agglutination test and enzyme-linked immunosorbent assay.

Sensitivity of anti-Toxoplasma antibody (IgG) test by enzyme-linked immunosorbent assay (ELISA) was evaluated in comparison with indirect latex agglutination (ILA) using 2,016 paired human samples of serum and cerebrospinal fluid (CSF). The samples were collected from neurologic patients in Korea with mass lesions in central nervous system (CNS) as revealed by imaging diagnosis (CT/MRI). When the sera were screened for anti-Toxoplasma antibody by ILA, 76 cases(3.8%) were positive (1:32 or higher titers). In the paired samples of CSF, no positive reactions were observed. When ELISA was performed using PBS extract of Percoll purified tachyzoites as antigen, cut-off absorbance was determined as 0.40 for serum and 0.27 for CSF tests. The antibody positive rates by ELISA were 7.0% in serum and 5.6% in CSF. Of them, 40 cases (2.0%) showed positive reactions in both serum and CSF. The antibody positive rates were higher in groups older than 40 years. The rates were higher in male (4.7% by ILA, 8.3% by ELISA) than in female (2.2% by ILA, 5.0% by ELISA). The rates in CSF showed no such sex difference. ELISA showed twice higher positive rates when serum was tested, and was sensitive enough to detect specific antibodies in CSF. Etiologic relations between positive antibody tests and CNS lesions remained unknown.

Diagnosis and epidemiology of toxoplasmosis in Korea

Toxoplasma gondii can cause congenital as well as postnatal toxoplasmosis in humans and animals, and thereby elicit various kinds and grades of clinical manifestations. In the human host, especially the congenital type gives rise to serious complications and sequelae such as blindness and hydrocephalus. Serological tests such as Sabin-Feldman dye test, indirect hemagglutination test, indirect fluorescent antibody test, indirect latex agglutination test, agglutination test, enzyme-linked immunosorbent assay, and detection of circulating antigens or antibodies are popularly used for the diagnosis of toxoplasmosis. In Korea, several local surveys during the past 20-30 years have shown that the antibody positive rates of patients in general hospitals ranged from 1.9% to 7.2%. Special clinical attention should be paid to immunocompromised patients, since immunosuppression is known to activate and aggravate latent toxoplasmosis, and in such cases the patients are often led to encephalitis, coma and death.

Toxoplasma antibody titers by indirect latex agglutination test in patients of Kangnam St. Mary's Hospital and Cheju Medical Center

Total 2,829 persons consisted of 1,019 general patients and 1,030 asthma-suspected patients who visited Kangnam St. Mary's Hospital and 780 general patients who visited Cheju Medical Center were examined for the antibody titers of Toxoplasma by indirect latex agglutination (ILA) test. Nineteen out of 1,019(1.86%) cases in general patients group, 11 out of 1,030(1.07%) cases in asthma patients group, and 45 out of 780(5.77%) cases in Cheju patients group showed positive ILA titers. Concerned with the age and ILA positive cases, general and asthma patients expressed more cases at thirties to sixties while Cheju patients showed high incidence at children and adolescents in addition to the above mentioned ages. Frequencies of ILA positive titers were highest in 1:32 and 1:64, and some cases showed 1:2,048 or higher titers.

A simple latex agglutination test for urinary albumin screening

In diabetes mellitus, urinary albumin excretion may be raised but below the sensitivity threshold of the usual urinary protein tests [l-4]. This albuminuria has been termed ‘microalbuminuria’ [5] and levels exceeding 50 mg/24 h have been found to be predictive of the onset of clinical proteinuria in insulin-dependent diabetics [5-71. This subclinical elevation of urinary albumin excretion, however, is potentially reversible and diminishes with the improvement of the metabolic control [2-B]. Microalbuminuria determination therefore may be an important examination in the identification of patients at risk for clinical diabetic kidney disease. The measurement of this variable by radioimmunoassay (RIA) has not become routine because the wide variations between daily measurements of microalbuminuria necessitate the performance of a large number of replicates. Other types of assay (e.g. turbidimetric and ELISA) [9-lo] have been proposed but these two are probably unsuitable for bedside and physician office use. Viberti and Vergani [ll] described a direct latex test which gives a positive answer in the range 2.5-16.6 mg/dl after 5 min. We now describe an indirect latex agglutination test which is sensitive enough (cut-off 40 mg/l) to identify diabetics at risk of clinical nephropathy. The method is a fast, simple, bedside test without prozone effect. The reaction time is about 1 min.

Modification of rowth rate of Toxoplasma gondii by continuous passage in immune mice

Growth of the RH strain of Toxoplasma gondii, is suppressed in mice immunized with Toxoplasma antigens. At the second passage, the growth of T. gondii harvested from immune mice is suppressed more strongly in immune mice than that of T. gondii from control mice. After 52 passages in immune mice, the growth of T. gondii was still suppressed in immune mice than in control mice. T. gondii did not possess ability of antigenic variation (Pfefferkorn et al., 1983). After vaccination with the S-273 strain of T. gondii, mice were challenged twice with the RH strain. Cysts in brains caused death of all mice by inoculation at the 1st, 2nd, 3rd, 4th and 8th week after the second challenge of the RH strain. But the cysts from mice at the 16th and 30th week have decreased virulence, causing death in only 2 out of 4 and 1 out of 4 mice, respectively. Virulence of cysts had no definite relationship to Toxoplasma antibodies by indirect latex agglutination test and the numbers of cysts per brain. Growth variation of T. gondii is proposed under unfavourable conditions as in mice immunized with Toxoplasma antigens or vaccinated with the S-273 strain.

Toxoplasma antibodies by indirect latex agglutination tests in zoo animals.

Total of 216 animals conserved in Seoul Grand Park were examined on the antibody titers of Toxoplasma by the indirect latex agglutination test, 20 out of 131 cases (15.3%) in mammals, 2 out of 75 cases (2.7%) in birds, and none in reptiles, according to species, 15 out of 68 species (22.1%) in mammals, 2 out of 36 species (5.6%) in birds showed positive antibody titers when the titers of 1:32 or higher were regarded as positive. In mammals, it appeared as positive in 2 out of 6 cases (1 out of 3 species ) in marsupials, 1 out of 15 cases (1 out of 11 species) in primates, 1 out of 1 case in bats, 6 out of 13 cases (5 out of 10 species) in carnivores, 1 in 12 cases (1 species out of 3) in odd-toed ungulates, 9 out of 80 cases (6 species out of 38) in even-toed ungulates, and none in rodents and in whales. In birds, 1 out of 21 cases (1 out of 7 species) in gallinaceous birds and 1 out of 6 (5 species ) in parrots appeared to have the positive antibody titers of Toxoplasma. And, none of reptiles showed positive. Frequencies of positive antibody titers were high in 1: 64, 9 cases in mammals followed by 1: 32, 6 cases, 1: 128, 3 cases, and 1: 256, 2 cases, respectively. Two positive cases in birds appeared to be 1: 64.

Significance of Toxoplasma antibody titers by indirect latex agglutination tests in pregnant women and pelvic tumor patients

A total of 377 pregnant women, 43 pelvic tumor patients and 80 of multiphysic health center persons as controls were examined by indirect latex agglutination test in order to evaluate Toxoplasma antibody titers at Kang-Nam St. Mary's Hospital in Seoul. Throughout this survey, 1:32 or more titers of diluted sera were regarded as positive. The 337 samples of test sera in pregnant women showed negatives in 319 cases (84.6 percent), 1:2 in 44 cases (11.7 percent), 1:4 in 9 cases (2.4 percent), 1:8 in 2 cases (0.5 percent), 1:16 in 1 case (0.3 percent) and 1:32 in 2 cases (0.5 percent) respectively. The 43 samples of test sera in pelvic tumor patients showed negatives in 29 cases (67.4 percent), 1:2 in 8 cases (18.6 percent), 1:4 in 1 case (2.3 percent), 1:16 in 2 cases (4.7 percent), 1:32 in 1 case (2.3 percent) and 1:128 in 2 cases (4.7 percent). The 80 samples of test sera in multiphysic health center persons as controls negatives in 56 cases (70.0 percent), 1:2 in 19 cases (23.8 percent), 1:4 in 3 cases (3.8 percent), 1:8 in 1 case (1.3 percent) and 1:128 in 1 case (1.3 percent). Among total 420 study cases, 5 cases (1.2 percent) showed positives, and they were 2 cases (0.5 percent) of pregnant women and 3 cases (7.0 percent) of pelvic tumor patients. One case (1.3 percent) out of 80 control sera showed positive result.

Toxoplasma Antibodies By Indirect Latex Agglutination Tests In National Seoul Mental Hospital Patients

A total of 573 patients hospitalized in National Seoul Mental Hospital and 76 of healthy persons as control were examined by indirect latex agglutination test in order to evaluate Toxoplasma antibody titers in mental patients. Throughout this survey, 1:32 or more titers of diluted sera were regarded as positive. The 573 samples of test sera showed negative in 386 cases (67.4 %), 1:2 in 93 cases (16.2 %), 1:4 in 57 cases (9.9 %), 1:8 in 14 cases (2.4 %), 1:16 in 12 cases (2.1 %), 1:32 in 5 cases (0.9 %), 1:64 in 1 case (0.2 %), 1:128 in 3 cases (0.5 %) and 1:256 in 2 cases (0.3 %) respectively. Among total 573 mental patients, 11 cases (19 %) showed positive, and they were 9 cases (1.8 %) of schizophrenia and 2 cases (7.4 %) of manic depression. One case (1.3 %) out of 76 control sera showed positive result.

Toxoplasma antibodies by indirect latex agglutination tests in St. Mary's Hospital patients

A total of 421 patients hospitalized in St. Mary's Hospital were examined by indirect latex agglutination test in order to evaluate the Toxoplasma antibody in Korean from June to August 1981. The test sera of the patients were obtained from each age group by random sampling. 1. The 421 samples of test sera showed negative in 153, 1:2 in 157, 1:4 in 59, 1:8 in 27, 1:16 in 7, 1:32 in 9, 1:64 in 2, 1:128 in 4 and 1:256 in 3 cases, respectively. 2. The positive rate of Toxoplasma antibody was 4.3 percent in this sample when indirect latex antibodies of 1:32 or higher were regarded as positive. 3. The titers of positive Toxoplasma antibodies were increased by age.