During an outbreak of parvovirus B19 we collected serum samples from 68 nonpregnant patients in the region of Antwerp (Belgium). Fifty-seven (84%) of the parvovirus B19 immunoglobulin M (IgM)-positive sera had a positive result for Epstein-Barr virus (EBV) IgM by Liaison testing, 61 (90%) had a positive result for herpes simplex virus (HSV) IgM, 20 (29%) samples were positive for cytomegaloviru...

Sucrose density gradient analysis of the fresh sera of patients with hereditary ataxia telangiectasia, disseminated lupus, and Waldenström's macroglobulinemia revealed the presence of an immunoglobulin possessing IgM determinants but having a sedimentation coefficient of approximately 7 S. Bio-Gel chromatography of patients' sera confirmed the presence of two distinct populations of IgM. The lo...

Detection of Japanese encephalitis virus (JEV)-specific IgM by IgM-capture enzymed-linked immunosorbent assay (IgM-capture ELISA) has been accepted as the standard for serological diagnosis. In the present study, we analyzed the time course of the positive rate of JEV-specific IgM in serum and cerebrospinal fluid (CSF) specimens from confirmed JE patients. Serum and CSF samples were obtained fr...

The marked increase in the total serum immunoglobulin M (IgM) is a characteristic feature of acute hepatitis A. To study the nature of this IgM, we assayed serial titers of IgM antibodies against various antigens during and after acute hepatitis A. The antibodies against blood group antigen remained unchanged throughout the observation period. Thus, the production or metabolism of IgM was not n...

We and others previously observed that IgM and CD40 stimulation in murine B cells resulted in activation of extracellular signal-regulated kinase (ERK), a subfamily of mitogen-activated protein kinase. The present study demonstrated that ERK was rapidly phosphorylated and translocated to the nucleus in murine B cells upon stimulation with CD40, whereas it was preferentially localized within the...

PURPOSE L612, a human IgM monoclonal antibody produced by an EBV-transformed human B-cell line, binds to ganglioside GM3 and kills GM3-positive human melanoma cells in the presence of complement. It has been shown to be effective in some patients with late-stage melanoma. L612 consists of hexameric IgM (about 20%), pentameric IgM (about 74%), and other minor IgM molecules. Because hexameric IgM...

Laser nephelometric estimation of IgM in the eluate fractions following Sepharose 6B chromatography has enabled the calculation of the proportion of low molecular weight IgM (7S IgM) in normal and pathological sera. This figure has then been used to determine the absolute amount of 7S IgM. Twenty-seven of 36 (75%) patients with rheumatoid arthritis had 7S IgM with a mean value of 17 mg/100 ml (...

Serum antibody detection tests and a urine antigen detection technique were compared in samples from 116 patients epidemiologically characterized as belonging to a legionellosis outbreak. Sera were tested by enzyme-linked immunosorbent assays (ELISAs) for immunoglobulin M (IgM) and IgG plus IgM and by immunofluorescent assays (IFAs) for IgG, IgM, IgA, and polyimmunoglobulin using commercial kit...