J Clin Pathol Qual Control.  1998 Jun;20(1):249-254.

Analysis of Cases Whose Sera Showed Coexistence of HBsAg and RF in Health Care Center

• Park JY
• Lim SH
• Kim YR
• Shin JW
• Kim HS
• Oh JJ

Abstract

BACKGROUND: Rheumatoid factors (RF) are associated most closely with rheumatoid arthritis but may be seen in certain other autoimmune diseases, viral hepatitis and even in healthy individuals, Since the prevalence of hepatitis B is relatively high in this country, it is thought that the positive rate and coexistence of RF and HBsAg may be also high. In this study, we evaluated the frequency and clinical significance of coexistence of HBsAg and RF. And, to rule out the possibility of false positive result of each test, we performed RF absorption and HBsAg neutralization test in RF and HBsAg positive sera, respectively.
METHODS
9,776 sera were obtained from the subjects undergoing health screening from January 1997 to December 1997. RF was detected by nephelometry (IMMAGE(TM), Beckman, U.S.A) and HBsAg by enzyme immunoassay (Cobas(R) Core II, Roche, Switzerland). Neutralization of HBsAg was performed by anti-HBs sera provided by Green Cross, Korea. After neutralization of HBsAg, RF test was performed again by nephelometry. RF absorption was performed by RF absorbent produced by Behring Diagnostics Inc., Germany and HBsAg test was performed again after absorption.
RESULTS
In 9,776 sera, RF was positive in 682 sera (6.98%) and HBsAg in 580 sera (5.94%). The positive rate of RF in HBsAg positive group is 28.28%, whereas in HBsAg negative group, it was only 5.64% (chi-square=430.37, P<0.001). There was no significant difference in HBsAg and RF results before and after the netralization and the absorption test (P=0.5397)
CONCLUSIONS
The positive rate of RF in HBsAg positive subjects undergoing health screening was significantly higher than that of HBsAg negative subjects. According to the results of HBsAg neutralization and RF absorption experiment, it was considered that there was no interference between HBsAg and RF test. Further studies about the exact mechanisms inducing RF production in HBsAg carriers and follow-up observations of those subjects will be needed.

MeSH Terms

Absorption
Arthritis, Rheumatoid
Autoimmune Diseases
Delivery of Health Care*
Germany
Hepatitis
Hepatitis B
Hepatitis B Surface Antigens*
Immunoenzyme Techniques
Korea
Mass Screening
Nephelometry and Turbidimetry
Neutralization Tests
Prevalence
Rheumatoid Factor
Hepatitis B Surface Antigens
Rheumatoid Factor