[Blood sampling systems and interference in immunoassay].

Immunoassay interference caused by reagents (additives, excipients) incorporated in the blood sampling systems is undetectable by the conventional methods for intralaboratory quality control, by using reference substances. A large number of manufacturers and a great physicochemical variety of additives in the current vacuum and non-vacuum systems require that additional measures be made to monitor systemic errors in immunochemical studies. The review considers the mechanisms of this type of interference and the problems of its monitoring and prevention.

[Clinical and hemodynamic characteristics of ischemic heart disease in patients with deficient body mass]. / Klinicheskie i gemodinamicheskie osobennosti ishemicheskoi bolezni serdtsa u lits s nedostatochnoi massoi tela.

AIM: To elucidate clinical and hemodynamic characteristics of patients with ischemic heart disease and low body mass. MATERIAL: Patients with stable angina (n=162) divided into 3 groups according to body mass index (below 25, 25-27 kg/m2 and above 27 kg/m2). RESULTS: Patients with low body mass index compared with those with intermediate values had worse clinical (arrhythmias, derangements of conduction, recurrent myocardial infarctions, cases with heart failure), hemodynamic (lower stroke volume and cardiac index, higher total peripheral resistance), and cardiometric (lower ejection fraction, larger diastolic volumes, greater relative myocardial mass) characteristics. CONCLUSION: These findings constitute a pathophysiological substrate for increased risk of death in patients with ischemic heart disease and deficient body mass.

[The distribution of antibodies to the herpes simplex virus in different types of raw material used for producing immunoglobulin preparations]. / Izuchenie raspredeleniia antitel k virus prostogo gerpesa v razlichnykh vidakh syr'ia, ispol'zuemogo dlia polucheniia preparatov immunoglobulinov.

The distribution of antibodies to herpes simplex virus (HSV) in different kinds of biological raw materials has been studied with the use of the enzyme-linked immunosorbent assay. The study has revealed that the content of herpes-specific antibodies in pooled placental and donor blood sera and in the preparations of commercial normal immunoglobulins is sufficiently uniform, and 7-10% of these sera and preparations have elevated titers of antibodies to HSV. Blood sera of individual donors are characterized by greater differences in the content of herpes-specific antibodies. About 10% of such sera have significantly greater titers of antibodies to HSV. From selected blood sera of individual donors with initially high titers of antibodies to HSV the preparation of antiherpes immunoglobulin has been obtained; the specific activity of this preparation is 4- to 6-fold higher than that of preparations of commercial normal immunoglobulins.

[Rheumatoid blood factors in patients with complicated spinal injury]. / Revmatoidnye faktory krovi u bolnykh s oslozhnennoi travmoi pozvonochnika.

Enzyme immunoassay (ELISA) was used to study the levels of serum rheumatoid factors (RF) of classes IgM and IgG in patients with spinal injuries and osteochondrosis. The findings show that at the late stages of the disease, the patients with spinal injury show 46% seropositiveness for IgG-RF and 40% for IgM-RF. Patients with fresh central nervous system (CNS) injuries were 12 and 14% seropositive, respectively. Patients with osteochondrosis exhibited 33% seropositiveness for IgG-RF. Determination of serum RF enables the authors to identify systemic body lesions at the late stages of spinal injuries as rheumatic disease. These data support the conclusion that RF determination is a reliable serological indicator of the severity of a patient's traumatic disease.

[Rheumatoid blood serum factors in patients with traumatic injuries of the spinal cord]. / Revmatoidnye faktory syvorotki krovi pri travmaticheskom povrezhdenii spinnogo mozga.

Enzyme immunoassay was used in the research of the levels of rheumatoid factor (RF) of IgM and IgG in the blood serum of patients with the injury of the spinal cord and osteochondroses. Analysis of the results obtained demonstrated a 46% RF IgG seropositivity and 40% RF IgM seropositivity in the patients with the injury of the spinal cord in the late period of the disease. The patients with freshly injured CNS demonstrated 12 and 14% seropositivity, respectively. Osteochondrosis patients demonstrated a 33% RF IgG seropositivity. The detection of the blood serum RF enabled one to qualify the systemic lesions at the injury of the spine cord in the late period of the disease as a rheumatoid condition. On the basis of the data obtained a conclusion could be made of fact that the detection of RF was a reliable serological test for the assessment of the severity of the condition associated with the injury sustained.

[A simple method of isolating monoclonal immunoglobulin M, possessing rheumatoid activity]. / Prostoi metod vydeleniia monoklonal'nogo immunobloulina M, obladaiushchego revmatoidnoi aktivnost'iu.

A simple procedure for obtaining highly purified preparations of native monoclonal (Waldenström's disease) immunoglobulin M possessing a rheumatoid activity (IgM-RF) has been developed. The method is based on the use of affinity chromatography with a new readily available adsorbent (immunoglobulin G-porous glass) and 3 M LiCl in Tris-buffer pH 8.3-8.4 able to induce the dissociation of the IgM-RF-IgG complex. The IgM-RF preparation thus obtained was characterized in terms of amino acid composition (relative to conventional monoclonal IgM), carbohydrate composition and structure of oligosaccharide moieties of a complex type. It was shown that some dissociation conditions for the IgM-RF-IgG complex routinely used to isolate IgM-RF provoke irreversible denaturation of IgM-RF when applied to a preliminarily purified complex.

[The role of circulating immune complexes in children with rheumatoid arthritis]. / Rol' tsirkuliruiushchikh immunnykh kompleksov u detei s revmatoidnym artritom.

The content of circulating immune complexes (CIC) was determined in 120 children with rheumatoid arthritis (RA). Of this number 24 children were included into the group with rheumatoid uveitis. For comparison a group of 33 children with arthritis of various genesis was examined. Determination of CIC showed that in RA children exhibited a high level of IC in the blood and the synovial fluid depending on the activity of the process, the presence of visceral manifestations and spread of the articular affection. Rheumatoid uveitis was not accompanied by any marked deviations in immunological indices as compared to an articular form of rheumatoid arthritis. An increased content of CIC in children with arthritis of various genesis allows one to consider that in rheumatoid arthritis its determination is of no diagnostic value though a considerable rise in their content is a prognostically unfavourable sign in this disease.

[Development and experience in the use of an immunoenzyme test system for determining specific antihemolysins in patients with measles]. / Razrabotka i opyt primeneniia immunofermentnoi test-sistemy dlia opredeleniia spetsificheskikh antigemolizinov u bol'nykh kor'iu.

To determine the physico-chemical nature of specific antimeasles antihemolysins, an enzyme immunoassay (EIA) system with the use of stable measles virus hemolysing antigen has been developed. The expedient method has been worked out: the antigen diluted 1:20 with the initial hemolytic activity in the direct hemolysis inhibition test equal to 1:64 and, for its fixation, 0.1 M carbonate-bicarbonate buffer solution, pH 9.6, are used; the fixation of the antigen is carried out at 4 degrees C for 16-20 hours. The final dilution of the serum, whose coloration significantly differs from that of the control, is considered to be the titer of antimeasles antihemolysins. Specific antihemolysins belonging to three classes of immunoglobulins, A, M and G, are synthesized in measles. The detection of IgM-antihemolysins in high titers on the first day of rash opens prospects for using the newly developed EIA system for the rapid diagnosis of measles.

[Sorption properties of polystyrene plates used in immunoenzyme analyses]. / Izuchenie sorbtsionnykh svoistv polistirolovykh planshetov, ispol'zuemykh v immunofermentnom analize.

The capacity of polystyrene carriers used in the enzyme immunoassay (EIA) for adsorbing 131I-labeled human serum albumin under different conditions has been studied, and the comparison of the plates manufactured by Dynatech AG (Switzerland) and by the Leningrad Works of Medical Polymers has been made. At the first stages of the reaction the antigen is separated from the carrier and the amount of the desorbed antigen depends on its initial dose and the dilution of the assayed sera. The irregular desorption of the antigen leads to misinterpretation of the results. Comparison of the polystyrene plates has shown that each plate is characterized by individual adsorption capacity, which impedes at present the standardization of EIA-based test systems.

[Immunoenzyme test system for the quantitative determination of tetanus antitoxin in vaccinated persons using horseradish peroxidase-conjugated staphylococcal protein A]. / Immunofermentnaia test-sistema dlia kolichestvennogo opredeleniia protivostolbniachnogo antitoksina u vaktsinirovannykh s ispol'zovaniem stafilokokkovogo proteina A, kon''iugirovannogo s peroksidazoi khrena.

An enzyme immunoassay (EIA) system for assays of tetanus antitoxin in vaccinees has been developed. As conjugate, staphylococcal protein A labeled with horse-radish peroxidase is used in this system. The possibility of using the newly developed EIA system in seroepidemiological surveys of the population is shown.

[Diagnostic test system for detecting the meningococcal antigen by erythro-immunoadsorption]. / Diagnosticheskaia test-sistema dlia vyiavleniia meningokokkovogo antigena metodom éritroimmunoadsorbtsii.

The authors have developed a test-system for detection of group A meningococcal polysaccharide, based on the sandwich erythro-immunoadsorption ultra-microtechnique with the use of the Terasaki plates as a solid-phase carrier. The system, equivalent to ELISA in its high sensitivity and specificity, is more rapid and less expensive, permitting the detection of 1 mg/ml of the antigen in 20 microliter of the tested liquid within an hour. The results of the study of CSF samples from 28 patients with meningococcal infection were in good correlation with the ELISA results. The new test-system is recommended for practical use as a routine technique for the specific diagnosis of meningococcal meningitis and for the control of the effectiveness of the treatment.