RITUXIMAB TREATMENT FOR INTERSTITIAL LUNG INJURY IN SCLERODERMA SYSTEMATICA

Abstract

Objective: to study the efficiency and tolerance of rituximab (RTM) treatment in patients with scleroderma systematica (SDS) with interstitial lung injury (ILI).Subjects and methods. The trial included 27 patients (26 women and 1 man) (mean age 45.7±13.0 years), with diffuse (n=13) and circumscribed (n = 14) forms and a disease duration of > 5 years in 63%. All the patients underwent chestcomputed tomography; examination of external respiratory function, including forced vital capacity (FVC) and diffusing capacity of the lung (DCL), as well as echocardiographic study. The efficiency of the treatment was evaluated from changes in FVC, skin score, and disease activity index. The indicators were compared prior to the treatment and one year after the first administration of RTM. The latter was injected with premedication (125–500 mg of methylprednisolone intravenously) 500–1000 mg per administration. The mean dose of RTM was low and amounted to 1.3 g per year.Results. As estimated by the physician, good, satisfactory, no effects were seen in 81.5, 14.8, and 3.7% of the patients, respectively. There was a significant increase in mean FVC one year after the first administration of RTM and a reduction in the total activity of the disease, including skin syndrome. DCL was substantially unchanged in the entire group. In the diffuse and circumscribed forms of the disease, FVC increased significantly and to the same extent. A clinically significant increase in FVC (by 11%) was achieved in patients with a disease duration of ≤5 years and mild lung injury. In people with a more than 5-year disease duration, FVC was initially decreased to a greater extent and the treatment-induced increase was only 3.7%. A significant and permanent decline in peripheral blood B lymphocytes was noted when both the standard dose (2 g) of RTM and its lower doses (0.5–1 g) were administered. RTM treatment was well tolerated, but complicated by mild intercurrent infections in 11% of cases within the first 2 months after RTM administration.Conclusion. The findings substantiate the indications for RTM use primarily in the early stage of the disease. The admittedly low doses of RTM have an inadequate effect if the disease is long-lasting. Further study of dosage regimensfor RTM is required within the framework of controlled trials.

Keywords

• scleroderma systematica
• rituximab
• forced vital capacity
• diffusing capacity
• b lymphocytes
• depletion