Three monoclonal IgG components, an IgG4(lambda), an IgG2(kappa) and an IgG1/IgG3 (kappa) Gm(f,b) hybrid, in a single myeloma patient.

An unusual triclonal IgG combination in the serum of a 56-year old male with clinical stage IIIB multiple myeloma is reported. The patient initially had an IgG4(lambda) monoclonal protein in his serum and later developed an IgG2(kappa) and an IgG (kappa) which possessed the characteristics of both IgG1 and IgG3 subclasses with an unusual combination of allotypic markers. Three M-proteins did not share idiotypic determinants. A rare class-switch recombination followed by mutation has been considered as a possible mechanism leading to this combination.

[Contamination of IgG preparation for intravenous use with IgA. I. Development of ELISA tests for determination of low concentrations of IgAc, IgA1, IgA2, IgG and IgM]. / Kontaminacija imunoglobulinima A preparata imunoglobulina G3A intravensku upotrebu. I) Razvoj postupaka enzimskog imunoeseja za merenje niskih koncentracija imunoglobulina A1, A2, G i M.

Very low amounts of immunoglobulin contaminants present in preparations of immunoglobulin G for intravenous use (IVIG) require sophysticated procedures for detection of such low concentrations in milieu of comparatively very high level of IgG. Standard RID and nephelometry procedures are not adequate for these purposes. In process of removal of IgA contamination from IVIG, which is currently under development in Blood Transfusion Institute, Belgrade, it is necessary to have senzitive and very specific procedures for determination of and follow up of very low concentrations of IgA remauning in IVIG. We have established a highly senzitive and specific ELISA precedures for determination of very low concentrations of total IgA (IgAc), IgA1, IgA2, IgG and IgM. Commercial standards of IgAc, IgA1, IgA2, IgG and IgM were bound to PVC plates coated with corresponding monoclonal antibodies anti IgAc-IgA1, anti-IgG and anti-IgM. Resulting standard curves have shown high correlation coeficients with limited range of detection (two orders of magnitude in nanogram range). Very high specificity of ELISA tests were obtained due to the highly specific monoclonal antibodies used. Very high specificity and very low detection level of developed tests are advantageous compared to standard procedures for Ig concentration determination.

[Contamination of IgG preparation for intravenous use with IgA. II. Removal of IgA1 from IgG preparation using affinity chomatography on lectin jacalin columns]. / Kontaminacija imunoglobulinima A preparata imunoglobulina G3A intravensku upotrebu. II) Uklanjenje imunoglobulina A1 iz preparata imunoglobulina G pomocu afinitetne hromatografije na koloni lektina zakalina.

Administration of preparations of IgG for intravenous use (IVIG) in individuals with high anti-IgA antibody levels in circulation is frequently accompained with anafilactoid reactions. Thus, there is a requirement for preparations of IVIG with very low levels of IgA. Reduction of IgA concentration in IgG preparations is generally difficult to achieve, since physical and chemical characteristics, on which proceses for Ig purification are based on, are similar for these two Igs. In this work the ability of lectin jacalin to selectively bind IgA1 subclass was exploited for removal of IgA1 from IVIG currently under development in Blood Transfusion Institute of Republic Serbia, Belgrade. Concentrations of Igs in this preparation of IVIG were measured by ELISA tests developed for these purposes. The results have shown 280 times decrease of IgA1 content without changes of IgG concentration. Therefore, affinity chomatography on jacalin column is a suitable method for removal of IgA1 subclass from IVIG. Because of a favourable pH and ionic strength conditions used in process, this procedure has no effect on native state of IgG.

[Modern immunologic tests in the diagnosis of Lyme borreliosis]. / Savremeni imunoloski testovi u dijagnostici lajm borelioze.

In this work we described the results that were obtained using various immunodiagnostic assays for the detection of lyme borreliosis. Sera of the patients that were in acute or chronical phase of the disease were analysed in indirect immunofluorescent, immunoenzyme and immunoblot assays which were prepared and carried out in our laboratory. As a control for the validity of these investigations, we used sera of the healthy people, as well as of the patients suffering of lues or rheumatoid illnesses. Results that we obtained pointed out the factors responsible for the nonspecific reactions in indirect immunofluorescent and immunoenzyme test. The advantage of the immunoblot analysis in detecting lyme borreliosis is described in this work.

Expression and localization of proteins of the complement system in human skin.

The complement system participates in the immune recognition of foreign antigens, many of which may penetrate the skin by physical injury or transcutaneous adsorption. In this study, we examined the presence of complement components and complement regulatory proteins in the human skin and cultured human keratinocytes. Immunofluorescence studies showed C3, Factor B, decay accelerating factor, the C3b receptor (CR1), and C3d receptor (CR2), distributed among cells of the epidermis as well as on cultured keratinocytes. Immunoblot analysis of keratinocytes supernatants showed the presence of C3 with a molecular weight of approximately 180 kD. The decay accelerating factor was localized as previously reported on elastic fibers; additionally it was observed in the basement membrane zone. In situ hybridization studies suggest the expression of CR1 and CR2 mRNA in human epidermis. These results show the presence in the human epidermis of complement components that are capable of generating the initial C3 convertase of the alternative pathway. The presence of complement regulatory proteins could endow keratinocytes with immune functions such as the regulation of complement activation and endocytosis of C3 opsonized particles.