There is common agreement that fibromyalgia (FM) is an extremely heterogeneous entity. Patients differ in their clinical symptoms, endocrine and immune parameters. In this study we evaluated endocrine and immunological features of distinct subsets of FM patients.
In contrast to previous attempts to identify subsets of FM patients, based solely on their psychological and cognitive features, herein we propose to separate FM patients by genetic features. Allelic expression of the polymorphic promoter region of the serotonin transporter (5-HTTLPR) was analyzed as a relevant genetic factor for FM.
Seventy-five patients meeting the American College of Rheumatology criteria and 27 healthy age-matched controls participated in this study. All controls and FM patients were submitted to genotyping of 5-HTTLPR. Twenty-seven FM patients, who were able to discontinue hypnotic, sedative or psychotropic prescription medications for at least 2 weeks, were then subdivided into L (homozygote LL) or S groups (genotypes LS and SS). They were evaluated for salivary cortisol levels, absolute number of leucocyte subpopulations, including natural killer (NK) cells and activated T and B lymphocytes.
• Both groups presented decreased cortisol levels, more intense in the L group, increased all B lymphocytes subsets and reduced CD4(+)CD25(high) T lymphocytes.
• The L group had increased CD4(+)CD25(low) activated T lymphocytes,
• While the S group displayed elevated CD4(+)human leucocyte antigen D-related (HLA-DR)(+) activated T lymphocytes and decreased NK cells.
We demonstrate that genetic factors may help to identify FM individuals with differentially altered frequencies of immune cells.
Source: Clinical and Experimental Immunology, Dec 2008; 154(3):346-52. PMID: 19037919, by Carvalho LS, Correa H, Silva GC, Campos FS, Baião FR, Ribeiro LS, Faria AM, d'Avila Reis D. Departments of Morphology, Psychiatry, Biochemistry and Immunuology, Universidade Federal de Minas Gerais; Governador Israel Pinheiro Hospital, Belo Horizonte, Minas Gerais, Brazil. [E-mail: LSC Carvalho firstname.lastname@example.org]