Possible protective effects of the Glu27 allele of ß2-Adrenergic receptor polymorphism in Thai asthmatic patients.

The genetic polymorphisms at the 16th (Arg-Gly) and 27th (GlnGlu) amino acid positions of the ß2-adrenergic receptor (ADRB2) may be linked to various asthma-related phenotypes. These include the adverse effects on lung function known to occur following the regular use of albuterol. The study aimed to determine the association between these two ADRB2 SNPs, their haplotypes and the phenotypes in Thai asthmatic patients. One-hundred and thirty asthmatic patients were genotyped at the Arg16Gly and Gln27Glu polymorphisms. Demographic data, disease severities, pulmonary function tests and medication usages were recorded for each patient. The frequencies of the Arg16 and Gln27 alleles were found to be 56.9% and 91.2%, respectively, while the linkage disequilibrium coefficient between the two SNPs was 0.36. Three haplotypes were estimated, i.e. Arg-Gln, Gly-Gln and Gly-Glu with frequencies of 148 (56.9%), 89 (34.2%) and 23 (8.9%), respectively. The mean percentages for predicted FEV1 (%FEV1) for these corresponding haplotypes were 73.5 (SD = 16.3), 72.4 (SD = 17.4)and 80.7 (SD = 13.1), respectively (p = 0.258). Additionally, the number of hospitalizations, emergency visits and inhaled corticosteroid/longacting ß2-agonist (ICS/ LABA) usages were lower in Gln/Glu subjects than for Gln/Gln genotyped patients, with values of 0% versus 11.9% (p = 0.122) for hospitalizations;4.5% versus 18.8% (p = 0.121) for emergency visits; and 50% versus 76.6%, (p = 0.042) for ICS/LABA usages. The presence of the Glu27 allele in Thai asthmatic patients is associated with a decreased asthma severity, higher %FEV1 values, less frequent hospitalizations and emergency visits, and decreased ICS/LABA usage.

Raising rheumatoid factor cutoff helps distinguish rheumatoid arthritis.

The presence of rheumatoid factor (RF) is one of the clinical criteria for the diagnosis of rheumatoid arthritis (RA). The cutoff point of RF assays is usually based on a reference level obtained from normal subjects in the same population as the patients. We evaluated 63 rheumatoid arthritis (RA), 25 other arthritis patients and 110 blood donors. Their rheumatoid factors (RF) ranged from < 9.9 to 2,264, < 9.9 to 262, and < 9.9 to 66 mIU/ml, respectively. The sensitivity at different cutoff points of 15, 20, and 25 mIU/ml was 92.1%, 90.5%, and 88.9%, respectively. The specificity at the same cutoff points was 81.5%, 84.4%, and 85.2%, respectively. Having minimally sacrificed the sensitivity, we recommend using a higher RF cutoff to increase specificity.