Anti-C1q antibodies in patients with systemic lupus erythematosus treated by rituximab

作者：Tsanyan M E^*; Torgashina A V; Aleksandrova E N; Soloviev S K; Nasonov E L

来源：Terapevticheskii Arkhiv, 2013, 85(5): 53-59.

• systemic lupus erythematosus
• a-C1q
• lupus nephritis
• Rituximab

Aim. To determine the time course of changes in the blood levels of antibodies (Ab) to complement component C1q (a-C1q) in patients with systemic lupus erythematosus (SLE) during rituximab (RTM) therapy and the association with organ injuries in SLE.
Subjects and methods. The study involved 41 patients (3 men and 38 women; their median age was 27.5 (range 22-36) years) with definite SLE. Their blood a-C1q levels were determined by enzyme immunoassay. The levels and detection rates of a-C1q were estimated in relation to organ injuries, the time course of RTM therapy-induced changes in a-C1q levels were determined. High-positive (>30 UN!), low-positive (10-30 U/ml), and negative (<= 10 U/ml) a-C1q levels were found.
Results. A-C1q was detected in 19 (46.3%) patients with different clinical manifestations of SLE. The patients with renal diseases had high-positive levels of a-C1q statistically significantly more frequently than those without renal involvement (p=0.04). Low-positive and negative a-C1q levels were found in 15 of 16 without nephritis. There was a statistically significant positive correlation of the concentration of a-C1q with Ab to double-stranded DNA (a-dsDNA), Ab to nucleosomes, the SLE Disease Activity Index 2000 (SLEDAI-2K), erythrocyturia, hematuria and a negative correlation between a-C1q and complement components C3 and C4. Just after one month of RTM therapy, the patients with nephritis were observed to have a statistically significant decrease in the levels of a-C1q (p=0.002), which persisted 1 year after the treatment (p=0.006). Nineteen patients with the higher baseline concentrations of a-C1q after RTM treatment showed a statistically significant decrease in the levels of a-C1q at 1-, 3-, 6-, and 12-month follow-up (p=0.016, 0.02, 0.035, and 0.04, respectively) which was accompanied by the decreased SLEDAI-2K (p<0.00004 at 1-, 3-, 6-, and 12-month follow-up).
Conclusion. The high levels of a-C1q were found statistically significantly more often in the patients with lupus nephritis than in those with SLE without renal involvement. The level of a-C1q statistically significantly reduced after RTM therapy and remained within the normal range during a year.

• 出版日期2013