Two distinct paraproteins (IgG(2)-K and IgM-K) from one patient shared identical light chains and significant portions of the variable regions of the heavy chains. Idiotypic determinants on the IgG and IgM molecules were shared. Earlier studies, using class-specific antisera, showed that these paraproteins were produced by two different populations of cells. The present study, using rhodamine a...

Quantitative and qualitative techniques for assessment of the intrathecal humoral immune response in human African trypanosomiasis were compared, and their diagnostic potential for detection of the meningo-encephalitic stage of the disease was evaluated. Total and trypanosome specific immunoglobulin G (IgG) and IgM intrathecal synthesis were studied in paired cerebrospinal fluid (CSF) and blood...

We investigated the ability of IgM-, IgD-, and IgG-bearing cells from the spleens of (BALB/c x C57BL/Ka)F1 mice primed to dinitrophenyl-bovine serum albumin (DNP-BSA) to restore the adoptive secondary anti-BSA and anti-DNP antibody responses. A rabbit anti-mouse IgD antiserum was prepared and the specificity documented by radioimmunoprecipitation, and cell surface staining. Purified populations...

Conserved differences between the transmembrane and cytoplasmic domains of membrane immunoglobulin (Ig)M and IgG may alter the function of antigen receptors on naive versus memory B cells. Here, we compare the ability of these domains to signal B cell allelic exclusion and maturation in transgenic mice. A lysozyme-binding antibody was expressed in parallel sets of mice as IgM, IgG1, or a chimer...

INTRODUCTION The purpose of this study was to quantitatively evaluate the contribution of synovial lymphoid aggregates to autoantibody (rheumatoid factor [RF] and anti-cyclic citrullinated peptide [anti-CCP]) and total immunoglobulin (IgG and IgM) production in rheumatoid arthritis (RA) patients and the effect thereon of the B-cell-depleting antibody, rituximab, in the ARISE (Assessment of Ritu...

We have found that Mg++ supports IgM complex binding to mouse lymphocytes but not to macrophages. In contrast, Ca++ supports IgM complex binding to macrophages but not lymphocytes. IgG complex binding to both lymphocytes and macrophages is divalent cation independent. These findings allow one to distinguish IgG from IgM binding and macrophage from lymphocyte IgM complex binding by their differe...

We investigated the ability of IgM-, IgD-, and IgG-bearing cells from the spleens of unprimed (BALB/c x C57BL/Ka)F1 mice to restore the adoptive primary anti-BSA and anti-DNP antibody responses. Purified populations of isotype-specific cells were prepared by immunofluorescent staining and sorting on the fluorescence activated cell sorter. Bright or dull cells were transferred to irradiated syng...

In some patients, the presence of monoclonal IgM proteins can cause substantial false elevation in nephelometric assays. A 59-year-old woman with previously unrecognized Waldenström macroglobulinemia had high serum viscosity. Nephelometric analysis revealed elevated measured concentrations of IgG, IgA, and IgM. Pretreatment with a reducing salt solution yielded resolution of cross-linked immuno...

Acute Toxoplasma gondii infection in early pregnancy carries the risk of transmitting the infection to the fetus with serious sequelae. However, serological testing for IgG/IgM anti-Toxoplasma antibodies may fail to differentiate between a recent and past infection. Two hundred and twenty-four Kuwaiti women in their first trimester were screened for IgG/IgM antibodies by the Vitek Immuno Diagno...