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1.
This paper gives the results of studies on various technical aspects of the indirect haemagglutination (IHA) test for malaria, on the similarity of the results obtained in the IHA test and in the indirect fluorescent antibody test, on the use of various plasmodial extracts as sensitizing antigens in the IHA test, and on the influence of heterophile antibodies on the titres obtained in the IHA test. Some longitudinal observations on induced malaria infections of man and monkey showed that the infection can induce the production of heterophile antibodies: their appearance, however, remains unpredictable. In some infections agglutinins against host erythrocyte components are also produced. Absorption of sera with tanned sheep cells sensitized with noninfected host red blood cell antigens is advocated as a control on the IHA titre for specific agglutinins.  相似文献   

2.
A multi-species thick smear antigen containing equal proportions of P. vivax, P. falciparum, and P. brasilianum schizonts was prepared for use in the indirect fluorescent antibody test for malaria. Tests with 80 sera showed that antibody titres with the multi-species antigen always equalled or exceeded the highest titre obtained when the sera were tested with the constituent mono-species antigens. Use of the multi-species antigen greatly reduces the time and labour required to screen serum specimens for malaria antibody. This study confirms the need for homologous antigens of all species to be detected if maximum sensitivity and reactivity are to be achieved.  相似文献   

3.
The reproducibility of the IHA test was assessed. Two batches of glutaraldehyde-fixed sheep cells were used and the cells were sensitized with different batches of P. falciparum antigen obtained from 4 owl monkeys. At the individual level the IHA test appears to have a reproducibility of approximately 90%.  相似文献   

4.
This paper describes the results of many years'' study of the indirect haemagglutination (IHA) test for brucellosis. It is shown that the use of sheep erythrocytes sensitized with a specific lipopolysaccharide antigen in the IHA test provides a specific method, which is more sensitive than the agglutination test, for the diagnosis of brucellosis in man and farm animals.  相似文献   

5.
Longitudinal observations were made on 6 Aotus monkeys repeatedly infected with Plasmodium falciparum (West African and Palo Alto strains). Immunofluorescence titres were higher than indirect haemagglutination titres in the primary phase of the infections. Both serological tests were consistently positive later in the infections. Precipitins were often not detectable even during episodes of parasitaemia.  相似文献   

6.
A longitudinal seroimmunological investigation of malaria was performed as part of the WHO research project conducted in the northern part of Nigeria from 1970 to 1975. The project included a preintervention phase, an intervention phase with application of malaria control measures (spraying of residual insecticide and mass drug administration), and a postintervention phase. Serological observations were made on the total population of eight villages consisting of approximately 3000 persons. Six immunological parameters were studied, namely, the serum levels of IgG and IgM, the number of bands of precipitation for Plasmodium falciparum in the double diffusion (Ouchterlony) test, the titres of antibodies for P. falciparum and P. malariae in the indirect fluorescent antibody (IFA) test, and the titres of agglutinating antibodies for P. falciparum by the indirect (passive) haemagglutination (IHA) test. The serological results were used to evaluate the impact on the humoral immune response of different levels of parasitaemia resulting, in the unprotected population, from natural factors such as seasons and ageing and in the protected population, from human intervention through the application of control measures and their interruption. The linkage by computer processing of the longitudinal data allowed analysis of the relationship between the results of a serological test in the same person at different surveys, and analysis of correlation between serological results and the concurrent parasitological findings. The correlation between parasitaemia and the results of the different serological tests at the same survey in the same person were also examined and analysed in terms of sensitivity and specificity of the tests.  相似文献   

7.
The indirect haemagglutination (IHA) test was compared with the complement-fixation (CF) test for the measurement of antibodies to Mycoplasma pneumoniae. A modification of the IHA was used to measure M. pneumoniae IgM antibodies. Sera were obtained from various groups of patients who were either culture or antigen positive for M. pneumoniae in nasopharyngeal aspirates or who had fourfold or greater increase in CF antibody or a titre greater than or equal to 320. The results of these comparisons showed that the modified IHA test was specific and more sensitive (89% as opposed to 64%) than the CF test. The modified IHA test for the detection of IgM antibody was highly effective in the recognition of recent or current infection with the mycoplasma. It was also of equal sensitivity to an indirect enzyme immunoassay for the detection of IgM antibodies to M. pneumoniae.  相似文献   

8.
Using the IgG fraction of a monospecific sheep antiserum against the circulating anodic antigen (CAA) of Schistosoma mansoni, an indirect haemagglutination reaction for the determination of this antigen was developed. This is the first time that an IHA has been applied to the detection of circulating antigens in parasite infections. The IHA proved to be highly sensitive; CAA levels up to 20 ng/ml could be measured. At the moment it appears to be the most sensitive technique for the determination of CAA levels. CAA could readily be detected in the sera of S. mansoni infected hamsters and in the immune complexes isolated from these sera, but never in sera from human schistosome infections.  相似文献   

9.
Preserved sera from patients with various forms of leishmaniasis, acute and chronic Chagas's disease and from normal individuals were examined for the presence of IgG and IgA antibodies by the IFA test. The leishmanial antigen used in the IFA test was prepared from a hamster infected with the PH8 strain of Leishmania mexicana amazonensis; amastigotes were isolated from a skin lesion and fixed in formal phosphate-buffered saline-glucose for slide antigen. There were significantly more positive reactions with IgA conjugate in patients with mucocutaneous leishmaniasis than in those with other forms. There was no association between IgA and IgG titres. The only two sera with trypanosomal IgA antibody were from two patients with acute Chagas's disease but neither sera produced cytoplasmic or surface fluorescence of leishmanial amastigotes. The implications of the presence of leishmanial and trypanosomal IgA antibody is discussed in detail.  相似文献   

10.
The sera of 20 Indian post kala-azar dermal leishmaniasis (PKADL) patients were analysed for immunoglobulin (IgG, IgM and IgA), third component of complement (C3) and specific antibody contents and the results compared with those of normal controls and kala-azar (KA) patients as obtained in an earlier study. Mean values of serum IgG and IgM in PKADL were found to be significantly higher than those of normal controls, although these values were substantially lower to those of KA patients. No significant difference, however, was noted in the mean levels of serum IgA and C3 between PKADL and control groups.Specific antibodies to Leishmania antigen could be demonstrated in PKADL sera by the indirect haemagglutination (IHA) and enzyme-linked immunosorbent assay (ELISA) methods. Most of these antibodies belonged to IgG class although some IgM antibodies were also demonstrable. Antibody titre ranges in PKADL sera were, however, definitely lower than those of KA sera. A reasonably good correlation between the severity of dermal lesions and IgG-ELISA titres was obtained. Of 12 chronic PKADL cases, only four and ten were found to be serologically positive by IHA and micro-ELISA methods respectively. All eight fresh cases were seropositive by both these tests. Analysis of the data suggests an over-all difference between the serological profiles of PKADL and KA patients.  相似文献   

11.
Sera from NMRI/NIH mice were tested for the presence of IgM and IgG anti-sporozoite antibodies using the indirect fluorescent antibody test (IFAT). Both IgM and IgG antibody titres were related to the number of immunizations with irradition-attenuated Plasmodium berghei sporozoites, and protection from challenge with subsequent non-attenuated sporozoites correlated with the pre-challenge antibody titre. Sera taken five days following challenge showed marked reductions in antibody titres, except for the group receiving the maximum (four) immunizations. Groups immunized with frozen sporozoites or mosquito tissue antigen developed neither antibodies to sporozoites nor protective immunity; nor did animals infected with parasitized blood. However, sera from mice immunized four times with attenuated sporozoites demonstrated IFA titres to blood-stage antigens. The results show that both IgM and IgG antisporozoite antibodies could be detected in mice immunized with attenuated-sporozoites by IFAT, and that the antibody titres correlated with protective immunity. Cross reaction with blood-stage antigens occurred, but the test should still prove useful.  相似文献   

12.
Using the indirect fluorescent antibody test and sera from 10 proved cases of invasive amoebiasis, the effects of absorption of IgG on observed titres of amoeba-specific IgM and IgA were investigated. In addition, results of cellulose acetate precipitin tests were compared with anti-amoebic antibody levels.Antiamoebic IgM was found at titres of 1:14 to 1:112 after IgG absorption in four cases. Antiamoebic IgA was detected in sera from four cases, but the maximum titre was 1:28. There was no relationship between the presence of amoeba-specific IgM or IgA and the result of the precipitin test, but a raised anti-amoebic IgG level was consistently found where the precipitin test was positive. However, sera with raised amoeba-specific IgG levels did not invariably give a positive precipitin reaction.  相似文献   

13.
Two infant populations, the one exposed to intense malaria transmission and the other protected, were followed and compared by six serological tests. The IgG and IgM levels increased with age and were systematically, though only slightly, lower in the protected children. The results of three Plasmodium falciparum tests (precipitin, indirect fluorescent antibody (IFA) and indirect haemagglutination and one P. malariae test (IFA) were high at birth and decreased rapidly afterwards in both populations. In the unprotected population, this decrease was followed by an increase, closely associated with the parasitological findings, while in the protected population the decrease continued to very low levels.  相似文献   

14.
Malaria parasites in mice present a simplified rodent model for the immunological study of malaria. Experiments have been performed to determine the pattern and persistence of malaria antibody as detected by the indirect fluorescent antibody (IFA) test utilizing specific antimouse IgM and IgG conjugates. The antibody levels in mice inoculated with Plasmodium berghei and treated with antimalarial drugs were traced after complete elimination of the parasites from the host. Within 1-2 weeks after inoculation, both specific IgM and IgG reached peak levels, which thereafter declined rapidly. The results suggest that a high IFA titre may be taken as an indication of recent parasitaemia when the parasites are absent from the host. The protective role of the specific immunoglobulin was not found in the cured animals at the time when the animals showed a high IFA titer. It seems that the detected IFA may not reflect protective immunity against reinfection with malaria parasites.  相似文献   

15.
Data are presented to support a relationship between malaria infection and Burkitt's lymphoma in African children. IgG, IgM and IgA levels were measured in sera from Burkitt's lymphoma patients and from sex- and age-matched, nearest-neighbour controls. All three classes of immunoglobulins were present in significantly lower amounts in the sera from Burkitt's lymphoma patients than in the sera from controls. The mechanism of this apparent B-cell suppression is not yet clear. Malaria-specific IgG and IgM antibody titres were determined in the indirect immunofluorescence test. No significant difference in the IgG malaria-specific antibodies was detected between the two groups of sera. Malaria antibody levels measured using IgM specific conjugates were significantly lower in the sera from Burkitt's lymphoma patients in reactions with Plasmodium falciparum antigen. No significant difference was observed when P. malariae was used. Confirmation of this finding would serve as a positive link between Burkitt's lymphoma and P. falciparum infection.  相似文献   

16.
138 sera from adult Europeans were tested with a commercially available latex agglutination test marketed in kit form under the trade name of Serameba. They were tested at the same time by the gel diffusion precipitin (GDP), fluorescent antibody (FAT) and indirect haemagglutination (IHA) tests. 52 sera were positive by at least one test; 47 by the IHA, and 43 of these by the Serameba. Whenever the IHA had a titre above 1 : 320, the Serameba was also positive. 5 sera positive by all 4 tests were absorbed with sensitized red cells; the absorbed sera gave negative IHA and Serameba tests, but their FAT and GDP results were unaffected. It is concluded that the Serameba is slightly less sensitive but otherwise equivalent to the IHA for clinical and epidemiological work; it is much simpler to perform. Its present disadvantage of expense could be largely overcome by some simple modifications in presentation.  相似文献   

17.
An indirect fluorescent test was developed for detecting antibodies to Paracoccidioides brasiliensis using bentonite particles as antigen (Bent-IF). The bentonite particles were coated with P. brasiliensis polysaccharide antigen and tested with sera from paracoccidioidomycosis patients (36 sera), normal blood donors (32 sera) and patients with non-mycotic diseases (29 sera). The titres given by the positive sera were compared with those of complement fixation (CF), immunodiffusion (ID) and immunofluorescent test using yeast forms of the fungus as antigen (conventional-IF). All normal blood donors' sera gave a negative Bent-IF, conventional-IF, ID and CF tests. All paracoccidioidomycosis sera were reactive in conventional-IF and gave concordant results in Bent-IF. There was no correlation between CF and Bent-IF titres. 27.6% of sera from patients with non-mycotic diseases gave weak titres in both IF-tests. The present data indicate that the Bent-IF is a sensitive and simple serodiagnostic technique comparable with the conventional P. brasiliensis antibody test.  相似文献   

18.
A mu-capture ELISA was developed for detecting Mycoplasma pneumoniae-specific IgM, and compared with an indirect immunofluorescent antibody (IFA) technique and an indirect ELISA. mu-capture ELISA and IFA compared well and were found to be the most sensitive assays. The IFA test can be completed in 2 h whilst the results of the mu-capture ELISA can be available in 24 h. Both tests are amenable to routine diagnostic use and have similar sensitivity. Indirect ELISA was found to be less sensitive and less specific, giving high assay values with several sera having undetectable M. pneumoniae CF antibody or CF antibody in low titre. Serum samples obtained from 11 patients at various times after M. pneumoniae infection showed maximum antibody levels within the first month by all assays, with a gradual fall in amount of IgM with time when assayed by mu-capture ELISA, a more gradual decline by IFA and hardly any decline with indirect ELISA. It was concluded that the indirect ELISA is unsuitable for the investigation of possible M. pneumoniae infection because the sustained high assay values with serum samples taken many months after infection, make interpretation of the test results very difficult.  相似文献   

19.
The specific reactivity of immunoglobulin M antibodies, as measured by a commonly used immunodiagnostic technique for schistosomiasis mansoni, the immunofluorescence assay (IFA) on Rossman-fixed sections of adult worms, was analyzed with monoclonal antibodies. Using monoclonal antibodies directed against 3 major gut-associated antigens, circulating anodic antigen (CAA), circulating cathodic antigen (CCA) and the 32 kDa antigen in blocking experiments, it was demonstrated that the measured IFA reaction was primarily due to reactivity with CCA. After blocking with anti-CCA monoclonal antibody, a mean decrease of fluorescent antibody titres of 95.8%, 92.9% and 83.8% was observed for sera from groups of patients with a recent infection (0-6 months), a static infection (6 months - 5 years), and a chronic infection (over 5 years), respectively. Titres of the group of recently infected patients were, after blocking, significantly lower (P less than 0.05) than those of the group of chronically infected patients.  相似文献   

20.
An important prerequisite for serological studies is the availability of specific antigens with which a high, consistently reproducible degree of test sensitivity can be obtained. In the present study, thick films of P. falciparum antigen were made from in vitro cultures in order to evaluate this antigen in terms of the sensitivity and reproducibility of the indirect fluorescent antibody test, as compared with an antigen prepared from washed infected erythrocytes of Aotus trivirgatus monkeys. The test was performed in 132 serum samples from 4 different sources. The results showed that the sensitivity and reproducibility of the two antigens compared well. No binding of donors'' antibody to antigen was noticed within the 24-hour period of in vitroculture.  相似文献   

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