[IgG4-related disease: patient group characterization and rituximab therapy].

AIM: To characterize a group of patients with IgG4-related disease (IgG4-RD) in a Russian population and to evaluate the efficiency of rituximab therapy. SUBJECTS AND METHODS: In 2009 to 2011, at the Research Institute of Rheumatology, Russian Academy of Medical Sciences, 30 patients (16 men and 14 women; mean age 44 years) were diagnosed with IgG4-RD that was confirmed by determination of serum IgG4 levels and immunohistochemical study of biopsy samples stained for IgG4-positive plasma cells. Seven patients received rituximab therapy. RESULTS: It was assumed at baseline that there were different types of neoplasias in 12 (40%), non-Hodgkin's and Hodgkin's lymphomas in 10 (33.3%), Sjögren's syndrome in 5 (16.7%), and Wegener's granulomatosis in 3 (10%). When 2 or more locations were involved, the condition was regarded as multifocal fibrosclerosis (33.3%). Localized forms were revealed in 20 (66.7%) patients. Among them, the largest number of patients was those who had orbital pseudotumor, Mikulicz's disease, or retroperitoneal fibrosclerosis. The most common sites of involvement were orbits (66.7%), salivary glands (70%) and lymph nodes (36.7%). Comparison of serum IgG4 levels in 28 patients with IgG4-RD, 22 patients with Sjögren's disease, salivary and lacrimal gland lymphomas, and 10 healthy controls showed that the concentration of IgG4 was significantly higher in Group 1 (median 2.6 g/I; IQR 1.22-4.65 (p < 0.001). Tissue IgG4/IgG ratio varied from 25 to 50% and averaged 38%. A moiré-like pattern of varying fibrosis was noted in 83% of cases. Analysis of laboratory data revealed elevated C-reactive protein concentrations (46.7% with a mean of 39.5 mg/l; normal values < 5.0 mg/l), increased erythrocyte sedimentation rate (60% with a mean of 37.6 mm/h), hypergammaglobulinemia (30% with a mean of 29.4%; normal range 13-22%), and rheumatoid factor (23.3%). After rituximab therapy, all the patients showed a decrease of IgG4 levels to the normal levels and positive changes evidenced by visualization techniques (computed tomography, magnetic resonance imaging). CONCLUSION: IgG4-RD is a novel problem in modern medicine, which requires a multidisciplinary approach and further study. Rituximab therapy is a promising treatment.

[Differential diagnosis of Wegener's granulomatosis and extranodal NK/T-cell lymphoma, nasal type].

Men aged over 40 years more commonly develop NK/T-cell lymphomas (NK/T-CL). The paper describes a case of NK/T-CL in a 20-year-old man. Despite the fact that the disease (nasal septum perforation, hard palate bone destruction, recurrent nasopharyngeal bleeding, considerable weight loss, and high erythrocyte sedimentation rate,) progressed rapidly for 5 months, the patient was found to be diagnosed as having Wegener' granulomatosis (WG). Repeated incisional biopsies showed massive necrotic changes with no clear histological verification of the diagnosis. The absence of lung and kidney lesions typical of WG, the lack of antineutrophil antibodies, and the detection of Epstein-Barr virus DNA in blood could presume NK/T-CL and confirm it by extended biopsy to have materials sufficient for morphological and immunomorphological studies. This observation shows that the disease may occur at a young age and rapidly progress; only early diagnosis can improve prognosis in patients with this type of lymphomas.