[Assessment of sensitivity of commercial test-systems for HBsAg immunodetection according to their ability to detect HBsAg-mutants of hepatitis B virus].

Comparative study of widely distributed on Russian market commercial test-systems for HBsAg detection by enzyme immunoassay was performed. Panel of serum samples containing mutant forms of HBsAg was developed for the study. It showed that only 2 out of 7 studied test-systems are able to detect mutant forms of HBsAg with the same sensitivity as "wild-type" forms of HBsAg. Test-systems based only on monoclonal antibodies did not detect HBsAg with G145R substitution in concentration 5 ng/ml. The study confirms the relevance of problem of HBsAg-mutants detection for hepatitis B immunodiagnostics.

[Algorithm of serologic screening and assessment of prevalence of serologically meaningful mutations of HBsAg in hepatitis B virus carriers].

Algorithm of serologic screening for HBsAg-mutants in hepatitis B virus (HBV) carriers with high level of HBsAg was developed which is based on the detection of defects of interactions of serum HBsAg with monoclonal anti-HBs realizing as a decrease of ELISA sensitivity in 10 times or more during serial 10-fold dilutions. During 1st stage commercial test-systems based on monoclonal antibodies was used to select serum samples with discrepancy of test results. During 2nd stage HBsAg contained in selected sera was analyzed by the panel of monoclonal and polyclonal anti-HBs conjugates using decrease in ELISA sensitivity as a criterion. Serum samples from 2510 chronic carriers of HBV with high level of HBsAg were studied. 19 samples with discrepant results were found. Subsequent characterization of HBsAg with panel of 11 monoclonal and 1 polyclonal conjugates allowed to distinguish groups of sera with specific serologic "portraits". Atypical features of HBsAg were confirmed by genotyping 9 of 19 samples. Analysis of primary nucleotide sequence revealed serologically meaningful mutations in S-gene of HBV in all 9 isolates: 3 of them contained substitution mutation G145R, 5--S143L, and one--T143M. Distribution of mutations in HBsAg corresponded with specific serologic "portraits". Prevalence of HBsAg mutations in HBV carriers with high level of HBsAg was assessed for the first time: prevalence of G145R, S143L/T143M mutations, and all serologically atypical variants was 0.12%, 0.24%, and 0.76% respectively. Developed algorithm was proposed for epidemiologic monitoring of HBsAg-mutants of HBVand control of diagnostic test-systems.

[Independence of alpha-fetoprotein expression from production of adult rat serum proteins in hepatoma McA-RH7777]. / Nezavisimost' ékspressii al'fa-fetoproteina ot produktsii belkov syvorotki vzroslykh krys v gepatome McA-RH7777.

Clonal cell lines were isolated from rat hepatoma McA-RH7777 to study expression of alpha-fetoprotein (AFP) in these clones. AFP contained by the cells was determined by immunofluorescent and immunoperoxidase staining, while AFP secreted into the medium by aggregate-hemagglutination and immunoisotachophoresis. The existence of the clones that drastically differ in the intensity of AFP synthesis was demonstrated, with these clones being implicated in the monitoring of AFP synthesis. The differences between the clones gradually diminished in the course of long-term cultivation. It was also shown that the clones under consideration secreted, apart from AFP, at least 8 proteins of adult rat serum. One of the proteins was identified as transferrin. No albumin was detected in the cultural media tested. The level of AFP production did not correlate with the synthesis of other serum proteins and thus seems likely to be controlled by an independent mechanism.

[Immunoautoradiographic determination of beta-1 gamma globulin in the blood serum of patients with trophoblastic tumors]. / Immunoautoradiograficheskoe opredelenie beta-1 gamma-globulina v syvorotke krovi bol'nykh s trofoblasticheskimi opukholiami

The authors determined beta1-G-globulin (beta1GG) in the sera of patients with different malignant tumours and of normal donors by means of the immunodiffusion method (ID) and immunoautoradiography (IAR). In the ID-negative sera beta1GG was revealed by means of IAR in 7 out of 8 patients with chorionepithelioma of the uterus and in 1 out of 7 patients with teratomblastoma of the testis before the treatment. After the treatment the beta1GG was determined in 7 out of 21 patients with chorionepithelioma of the uterus. At the early stage of trophoblastic tumours of the uterus beta1GG could be found in 77.7% of cases by means of IAR and in 16.8% of cases by means of the ID method.