Immunoglobulin isotypes

It is an autoantibody whose autoantigen is the Fc portion of IgG. Rheumatoid factors may be of any immunoglobulin isotype but it is IgM rheumatoid factor that is commonly measured in rheumatoid arthritis. Classification criteria for rheumatoid arthritis include only one serological test, namely rheumatoid factor. However, it is not diagnostic test rather it may be confirmatory when a number of other clinical features are present. 

Williams, D.J. and Behnke, J.M. (1983) Host protective antibodies and serum immunoglobulin isotypes in mice chronically infected or repeatedly immunized with the nematode parasite Nematospiroides dubius. Immunology 48, 37—17. 

Five major sub-classes of immunoglobulin (isotypes) (Table 7.1) have... 

IMMUNODEFICIENCY WITH HYPER-IGM (HIGMl), AN IMMUNOGLOBULIN ISOTYPE SWITCH DEFECT CHARACTERIZED BY ELEVATED CONCENTRATIONS OF SERUM IGM AND DECREASED AMOUNTS OF ALL OTHER ISOTYPES. AFFECTED MALES PRESENT AT AN EARLY AGE (USUALLY WITHIN THE FIRST YEAR OF LIFE) RECURRENT BACTERIAL AND OPPORTUNISTIC INFECTIONS, INCLUDING PNEUMOCYSTIS CARINII PNEUMONIA AND INTRACTABLE DIARRHEA DUE TO CRYPTOSPORIDIUM INFECTION. DESPITE SUBSTITUTION TREATMENT WITH INTRAVENOUS IMMUNOGLOBULIN, THE OVERALL PROGNOSIS IS RATHER POOR, WITH A DEATH RATE OF ABOUT 10% BEFORE ADOLESCENCE. 

In this method, the primary antibodies are combined into a single cocktail and applied simultaneously in a single-reaction step. The same is done for the labeled secondary antibodies. Antibodies of different animal species or immunoglobulin isotypes (noncrossreactive) or autologous antibodies that are directly coupled to different enzymes/fluorochromes are required. Immuno-fluorescent methods are particularly suited for this method. 

Such a control antibody is known as an isotype control because it is of the same immunoglobulin isotype (subclass) as the staining antibody used in the experiment. It will allow you to determine how much background stain is due to irrelevant stickiness (dead cells, Fc receptors, and so forth). The only trouble with this scenario is that exactly correct isotype controls are not usually available. Various manufacturers of monoclonal antibodies will sell so-called isotype controls and will certainly recommend that they be used. These are, however, general purpose isotype controls that will be of an average... 

Immunoglobulin Isotype Molecular Weight Carbohydrate Content (%) Serum Concentration" Biological Properties... 

The complex contains haptens, often multiple, coupled to a protein-containing carrier molecule, and can induce T cell-dependent B cell activation, leading to the formation of antihapten antibodies. The mechanisms that govern the selection of the different immunoglobulin isotypes are reviewed elsewhere (207). 

Brenner MK, Wimperis JZ, Reittie JE, Patterson J, Asherson GL, Hoffbrand AV, Prentice HG. Recovery of immunoglobulin isotypes following T cell depleted allogeneic bone marrow transplantation. Br J Haematol 1986 64(l) 125-32. 

Immunoglobulin isotype switching IgE production of anergic Th2 cells... 

In a patient suspected of having humoral immune deficiency or B-lymphocyte failure (i.e., primary and secondary immunodeficiency), specific immunoglobulin isotypes in the plasma should be measured. 

Allergic drug reactions can involve most of the major components of the immune system, including the cellular elements, immunoglobulins, complement, and cytokines. Most immunoglobulin isotypes have been imphcated in immunologically mediated drug reactions. 

If a patient is suspected to suffer from a certain autoimmune disease, tests on immunoglobulin levels may give an indication that such a patient has a dysregulated immune system. In general, all immunoglobulin isotypes and subclasses can be detected in the human circulation. Since antibody production is the consequence of immune stimulation, it is evident that immunoglobulin levels... 

Many different immunoassays can be used for the quantification of immunoglobulin isotypes and subclasses, varying from ELISA/ FEIA and radial immunodiffusion (RID) to nephelometry/turbid-imetry (Rose et al., 2002). The immunoglobulin isotypes IgA, IgG, and IgM in particular are present in relatively high concentrations in the circulation (0.5-20 g/l). These isotypes are often quantified by... 

Flores Romo, L., Millsum, M. J., Gillis, S., Stubbs, P., Sykes, C., and Gordon, J. Immunoglobulin isotype production by cycling human B lymphocytes in response to recombinant cytokines and anti-lgM. Immunology 69, 342-347 (1990). 

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