RESUMEN
OBJECTIVE: Rheumatoid arthritis (RA) is an autoimmune disease that affects mostly women and is associated with HLA-DRB1 genes having in common a shared epitope sequence. In parallel, cells and/or DNA originating from pregnancy (microchimerism) persist for decades and could contribute to autoimmunity. The aim of this study was to examine whether microchimerism may be a source of the shared epitope among women with RA. METHODS: Women with RA and healthy women who lacked RA-associated genes such as HLA-DRB1*01 (n=33 and n=46, respectively) and/or HLA-DRB1*04 (n=48 and n=64, respectively), were tested for DRB1*01 or DRB1*04 microchimerism by HLA-specific quantitative polymerase chain reaction assays. As controls, alleles not associated with RA (DQB1*02 and DRB1*15/16) were also analyzed. RESULTS: Compared with healthy women, women (42% with RA had a higher frequency and higher levels of DRB1*04 microchimerism versus 8%; P=0.00002) as well as DRB1*01 microchimerism (30% versus 4%; P=0.0015). Moreover, no difference in microchimerism was observed for alleles not associated with RA. CONCLUSION: Women with RA had microchimerism with RA-associated HLA alleles, but not with non-RA-associated HLA alleles, more often and at higher levels compared with healthy women. These observations are the first to indicate that microchimerism can contribute to the risk of an autoimmune disease by providing HLA susceptibility alleles.
Asunto(s)
Artritis Reumatoide/genética , Quimerismo , Epítopos/genética , Antígenos HLA-DQ/genética , Antígenos HLA-DR/genética , Intercambio Materno-Fetal/genética , Artritis Reumatoide/epidemiología , Femenino , Genotipo , Cadenas beta de HLA-DQ , Cadenas HLA-DRB1 , Humanos , Madres , Embarazo , Factores de RiesgoRESUMEN
OBJECTIVE: Evidence-based counseling and prevention are not available so far for hereditary cancer prone persons, since we lack data based on clinical trials. There are very few high-risk persons in the population as a whole. Based on a familial history analysis, only 1.2% of all healthy volunteers attending screening centers reached the arbitrary high-risk level defined as a Relative Risk of more than 4. We describe a randomized trial based on colonoscopic screening for colorectal cancer on a sub-group of high-risk group persons. MATERIALS AND METHODS: Among the 77 members of the French Institutional Preventive Center Network, 37 took part in this protocol. During the first 3 years, 850,000 persons were interviewed at these 37 Health centers. The enrollment process was particularly time-consuming, since a large amount of information had to be delivered to the participants. RESULTS: The mean rate of recruitment of eligible candidates was far lower than predicted, averaging only 1.4 per 1,000 persons interviewed instead of the 9/1,000 expected. This mean figure was based, however, on inclusion rates ranging from 0.06/1,000 to 7/1,000 among the different centers. The low rates of recruitment were mainly due to the inter-center heterogeneity (differences in commitment and in the resources), and to the fact that the acceptability of undergoing a colonoscopy turned out to be lower than predicted. CONCLUSION: Population trials on cancer prone persons are feasible, but vast numbers have to be pre- screened to identify the few people with a high hereditary risk and willing to accept screening within a controlled trial.
Asunto(s)
Colonoscopía , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/genética , Predisposición Genética a la Enfermedad , Adolescente , Adulto , Anciano , Neoplasias Colorrectales/epidemiología , Diseño de Investigaciones Epidemiológicas , Femenino , Francia/epidemiología , Humanos , Incidencia , Masculino , Tamizaje Masivo , Persona de Mediana Edad , Selección de Paciente , Factores de RiesgoRESUMEN
BACKGROUND: Muscle relaxants (MR) are responsible for 59% of peroperative anaphylactic reactions. A major issue would be to determine whether a systematic preoperative screening in the general population should be recommended. OBJECTIVE: The purpose of the study was to evaluate the prevalence of muscle relaxant sensitivity in a sample of the general population and to assess the role of possible risk factors. METHODS: Two hundred and fifty-eight subjects, aged 20-40 years, visiting a health care centre for a check-up were evaluated. Protocol included a questionnaire (occupation, symptoms of atopy, previous surgery, history of drug allergy), skin-prick tests to four commercial muscle relaxants and measurement of specific IgE against quaternary ammonium ions. Atopy was evaluated by skin-prick tests to common inhalant allergens and by a Phadiatop test. RESULTS: Of the study group, 9.3% had either a positive skin test to one or more muscle relaxant or a presence of specific IgE to quaternary ammonium ions. No risk factor was identified in the studied group. CONCLUSION: Since the rate of MR sensitivity is much higher than the anticipated rate of peroperative reactions due to allergy, a systematic preoperative screening for MR allergy should not be recommended for adults in a general population.
Asunto(s)
Hipersensibilidad Inmediata/diagnóstico , Relajantes Musculares Centrales/efectos adversos , Adulto , Femenino , Francia/epidemiología , Humanos , Hipersensibilidad Inmediata/inducido químicamente , Hipersensibilidad Inmediata/epidemiología , Masculino , Pancuronio/efectos adversos , Cuidados Preoperatorios , Prevalencia , Pruebas Cutáneas , Succinilcolina/efectos adversos , Encuestas y Cuestionarios , Compuestos de Tetraetilamonio/efectos adversos , Bromuro de Vecuronio/efectos adversosRESUMEN
BACKGROUND: Because latex is a common allergen, the rate of latex sensitization may be high in the general population. A major issue would then be to determine whether a systematic preoperative screening in the general population should be recommended. OBJECTIVE: The purpose of the study was to evaluate the prevalence of latex sensitization in a sample of the general population and to assess the role of possible risk factors. METHODS: The subjects were 258 people, aged from 20 to 40 yr, visiting a health care centre for a check-up. The protocol included: a questionnaire (occupation, symptoms of atopy, use of latex goods and possible reactions, history of previous surgery), a skin-prick test, and a CAP RAST to latex. Atopy was evaluated by a skin-prick test to common allergens and a Phadiatop test. RESULTS: Some 6.6% of the study group had either a positive skin test or a positive RAST to latex. These subjects had a four-fold higher prevalence of symptoms when wearing gloves. The rate of latex sensitization was higher by fivefold in subjects with a history of reactions to latex goods and by fourfold in atopic subjects. CONCLUSIONS: Because the rate of latex sensitization is much higher than the anticipated rate of perioperative reactions due to latex allergy, a systematic preoperative screening for latex allergy should not be recommended for adults.
Asunto(s)
Hipersensibilidad Inmediata/etiología , Hipersensibilidad Inmediata/prevención & control , Goma/efectos adversos , Adulto , Alérgenos , Femenino , Humanos , Hipersensibilidad Inmediata/diagnóstico , Masculino , Tamizaje Masivo , Cuidados Preoperatorios , Prueba de Radioalergoadsorción , Pruebas CutáneasRESUMEN
OBJECTIVES: To analyze the association between colorectal cancer positive family history and screening practices. METHODS: The study concerned 6733 individuals attending a center for periodic health examination. RESULTS: Five hundred fifty four patients (8.2%) declared a positive family history of colorectal cancer; 269 (4%) were first degree relatives of the affected member and among them, 73 (1.1%) have pointed out the occurrence of at least one cancer case below age 50. Out of 554 subjects with a family history (regardless the degree of kinship), 132 (23.8%) have had an endoscopic examination versus 8.9% of subjects without positive family history. The rate of endoscopy increased with the number of cases in a family (P < 0.0001). CONCLUSION: Family members undertake more endoscopic examinations when a family history of colorectal is reported. A correlation with the number of affected relatives has been found.