Rheumatoid factor in systemic lupus erythematosus : does it protect against nephritis?

الملخص EN

It has been suggested again recently that, the presence of rheumatoid factor (RF) in the serum of patients with systemic lupus erythematosus (SLE) protects them from development of nephritis.

In this study the RF urns measured by the standard latex test, and by RIA which detect IgM, IgA and IgG isotypes in 45 patients (34 females and 11 males) classified into three groups.

Group I: SLE with evidence of nephritis (15).

Group II: SLE with no evidence of renal involvement (15).

Group III: Idiopathic nephritis as a control (15).

Also, 9 patients from group I were studied during active and inactive phases of their disease.

The results showed that, only 7 patients (23.33%) were RF positive among SLE patients studied; 2 in group I (2333%) and 5 in group II (33.33%), with insignificant differences between percent positivity in the two groups.

Insignificant differences were found when comparing the means of serum creatinine level, blood urea concentration, systolic and diastolic blood pressure, and RBCs/HPF in urine between RF positive and RF negative cases of SLE (p > 0.05).

It is concluded that, although a trend towards a protective role for RF against the development of lupus nephritis was seen, however, this was not statistically significant.