title: Serendipitous evidence of T lymphocyte activation in close female relatives of patients with systemic lupus erythematosus.
abstract: A well-recognized characteristic of the autoimmune disease, systemic lupus erythematosus (SLE), is the high level of activated T cells present in the blood. Because of the increased size and granularity of activated T cells, in flow cytometry one might expect to find increased numbers of cells falling outside a standard light-scatter lymphocyte gate, and indeed we now report that the percentage of T lymphocytes in the gate (% TiG) was below the normal range in 23 of 58 (40%) female patients because of increased scatter values. However, the surprising additional observation was made that 18 of 30 (60%) female first-degree relatives of the patients also fell below the normal % TiG range, suggesting the presence of T cell activation in these relatives. This view is strengthened by the strong inverse correlation between plasma total immunoglobulin G(IgG), which was raised in some relatives, and % TiG, as T cell activation is a requirement for IgG production. Conversely, there was no correlation with IgM, which has no comparable link with T cell activation. While a definitive interpretation must await the demonstration of activation antigen expression in relatives, these findings suggest the existence of a T cell activation trait, not harmful in itself, which, however, contributes to the development of disease in patients with SLE.
authors: Department of Immunology, Imperial College School of Medicine, London, UK.
authors: M R J
authors: MR
authors: Green
authors: A S M
authors: AS
authors: Kennell
authors: M J
authors: MJ
authors: Larche
authors: M H
authors: MH
authors: Seifert
authors: D A
authors: DA
authors: Isenberg
authors: M R
authors: MR
authors: Salaman
mesh_terms: D000328:Adult; D015551:Autoimmunity; D015415:Biomarkers / Q000097:blood; D017252:CD3 Complex / Q000032:analysis; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D017678:Sex Distribution; D035781:Siblings; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D015415:Biomarkers; D017252:CD3 Complex; D007074:Immunoglobulin G; D007075:Immunoglobulin M