Tehran University Medical Journal

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Background: Rheumatoid factor (RF) is an IgM antibody against the Fc portion of IgG, which together form an immune complex. RF is an important criterion in the diagnosis of early-stage rheumatoid arthritis (RA) and prognosis of RA pathogenesis, as higher levels of RF indicate a higher possibility of more damage. Although 2/3 to 3/4 of patients that undergo ordinary standard tests and have final clinical diagnosis are also positive for RF, a 70-90% prevalence of RF among RA patients can be achieved, depending on the method of detection and the target antibody, IgG or IgM. In this study, we measured the frequency of IgG and IgM RF isotypes using the ELISA and latex agglutination methods and compare these results with those of a hospital control group, tested using standard methods, in order to determine the best method for the measurement of RF.

Methods: Of the patients referred to the Rheumatology Clinic of Imam Khomeini Hospital during 2005-2006, one hundred randomly selected rheumatoid arthritis patients, 75 females and 25 males, with classical or definite rheumatoid arthritis (defined by the criteria of the American College of Rheumatology), with a short disease duration of 12-24 months, underwent testing for RF using the latex method for IgM and ELISA for IgM-IgG. The healthy control group (75 females and 25 males) were tested for RF using the ELISA method for IgM-IgG. The variables were compared using the Pearson's chi-square test.

Results: We found that the measurement of RF among RA patients using did not differ significantly between the two methods. The immune complex in RA is mainly IgM. The positive IgM results in RF patients using two similar methods showed a significant relationship by Pearson's correlation co-efficient (r=0.60, p<0.001). In addition, comparison of the IgM and IgG RF by ELISA showed a weak correlation with low significance (r=0.10, p<0.001). In sum, this study showed a significant difference (r=0.24, p<0.001) between the IgM in RA patients and that in healthy people, who had no IgM or IgG RF.

Conclusion: Approximately 75% of confirmed RA cases had the IgM RF however, we found little advantage in using the one method over the other, nor was the measurement of IgG more useful than IgM as a diagnostic criteria.

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Background: Dermal- respiratory reactions to latex glove is a common problem and sometimes life threatening. Among health care workers, dental working personnel have extensive use of latex gloves. A few numbers of researches have been done in Iran about prevalence of these reactions but there is no comprehensive study for dental workers. The purpose of this study was to evaluate reactions to latex gloves amongst dental workers in military dental health centers.
Methods: In this cross-sectional descriptive survey, dental workers with a minimum of three months length of employment and most often use of latex gloves were asked to fill standard questionnaire (derived from South Carolina Medical University) regarding latex related clinical manifestation and personal medical history and predisposing factors Data analysis was done by χ2 and Student's t test.
Results: In our study 330 personnel were assessed. The mean age and length of employment was 31.6 and 8 years respectively. The most occupation was dentistry. A total of 232 subjects (70.3%) reported latex gloves-allergic symptoms. 72 (21.8%) of persons have history of atopy and food allergy was seen in 114 (34.5%). 63 (19.1%) of subjects reported history of hand dermatitis. All of these predisposing factors had positive regression with dermal and respiratory reactions.
Conclusion: In this survey the prevalence of allergic reactions was higher than similar studies which may be due to type of gloves, lack of preemployment assessments and other factors. Use of diagnostic methods such as serologic measures, SPT and pulmonary function testing (such as spirogram) could be considered as tools for confirmatory and differential diagnosis and important complementary for these studies. Because of relationship between allergic reactions to latex gloves and some medical histories, it seems to be necessary for preemployment evaluation and periodic health surveillance of dental workers.