Deficiency of somatic hypermutation of immunoglobulin G transcripts is a better predictor of severe respiratory tract infections than lack of memory B cells in common variable immunodeficiency.

Defects of memory B cells and of somatic hypermutation (SHM) are involved in the pathogenesis of common variable immunodeficiency (CVID). Here we report for the first time a systematic study of the relationship between memory B cell deficiency and SHM abnormalities in CVID, and relate these variables to prediagnostic infections. Isotype switched Vh3-23 transcripts were undetectable or low in 30% (IgG) and 63% (IgA) of the patients, but never in controls (P < 0.

Deficiency of somatic hypermutation of the antibody light chain is associated with increased frequency of severe respiratory tract infection in common variable immunodeficiency.

Reduced levels of somatic hypermutation (SHM) have recently been described in IgG-switched immunoglobulin genes in a minority of patients with common variable immunodeficiency (CVID), demonstrating a disruption of the normal linkage between isotype switch and SHM. To see if, irrespective of isotype, there is a tendency to use unmutated immunoglobulin genes in CVID, we studied SHM in kappa light-chain transcripts using a VkappaA27-specific restriction enzyme-based hot-spot mutation assay (IgkappaREHMA). Hot-spot mutations were found in 48% (median; reference interval, 28%-62%) of transcripts from 53 healthy controls.

Maturation of human dendritic cells by monocyte-conditioned medium is dependent upon trace amounts of lipopolysaccharide inducing tumour necrosis factor alpha.

We investigated the ability of monocyte-conditioned medium (MCM), generated by monocytes cultured on plastic-immobilised immunoglobulin, to stimulate maturation of human monocyte-derived dendritic cells (DC). Earlier reports suggest that MCM is a strong inducer of irreversible DC maturation, whereas we find, that adding a small amount of lipopolysaccharide (LPS) to the MCM-generating cultures is required for the production of a DC-stimulatory MCM. Moreover, compared with addition of LPS directly to the DC cultures, stimulation via MCM cultures increases by several fold the DC-stimulatory potency of LPS.

Low levels of mannose-binding lectin do not affect occurrence of severe infections or duration of fever in acute myeloid leukaemia during remission induction therapy.

Purpose: To estimate the clinical significance of low serum concentrations of mannose-binding lectin (MBL) in patients with acute myeloid leukaemia (AML) during initial cancer chemotherapy.

Patients And Methods: 80 consecutive, newly diagnosed, and unselected AML patients (age 18-77 yr) undergoing remission induction chemotherapy. The patients were examined for 28 d.