Clinical response, pharmacokinetics, development of human anti-chimaeric antibodies, and synovial tissue response to rituximab treatment in patients with rheumatoid arthritis

OBJECTIVES

To analyse whether persistence of synovial B lineage cells and lack of clinical response to rituximab treatment in patients with rheumatoid arthritis (RA) are associated with low rituximab serum levels and anti-rituximab antibody (ARA) formation.

METHODS

Fifty-eight patients with RA were treated with rituximab. The clinical response was determined 24 weeks after each treatment course using the Disease Activity Score evaluated in 28 joints (DAS28) and EULAR response criteria. Rituximab serum levels, ARAs and synovial B lineage cell numbers were determined before and after treatment.

RESULTS

Four weeks after treatment rituximab serum levels were highly variable. Low rituximab levels were associated with ARA formation (in five patients (8.6%)) and high baseline erythrocyte sedimentation rate. Interestingly, serum rituximab levels were not related to persistence of synovial B lineage cells or clinical response. Furthermore, response to treatment and re-treatment was similar in ARA-positive and ARA-negative patients.

CONCLUSION

There is clear variability in serum levels after rituximab treatment, but rituximab levels are not lower in patients with persistence of synovial B lineage cells or lack of clinical response. The current treatment schedule suffices to induce and maintain a clinical response, even when ARAs are formed.

Oral health status among 12-year-old children in primary schools participating in an oral health preventive school program in Phnom Penh City, Cambodia, 2002

A cross-sectional survey was undertaken to assess dental caries status, knowledge, attitude and practice in oral health among 12-year-old primary schoolchildren participating in the Oral Health Preventive School Program (OHPSP) conducted since 1998 in Phnom Penh City, Cambodia. Schools were stratified into 3 groups by levels of cooperation (good, partial, and poor) with the OHPS program and samples of schools randomly selected from each group. A total sample size of 239 schoolchildren was randomly selected from the sampled schools. There were 79, 82, and 79 children from schools with good, partial, and poor cooperation, respectively. Dental caries status DMFT (Decayed Missing Filled teeth) and knowledge, attitude and practices in oral health were assessed from 21 January to 5 February 2002. Opinions of school directors toward the OHPS Program were evaluated by interview. The results showed the overall mean DMFT per person in schoolchildren in Phnom Penh City, Cambodia of 2.33 (95%CI=2.05-2.61) while mean DT(Decayed teeth) was 2.31 (95%CI=1.97-2.52) and mean MT (Missing teeth) and mean FT (Filled teeth) were 0.01 per person, which were quite small. Children from schools with good cooperation with the OHPSP had the lowest significant mean DMFT 1.62 (95%CI=1.25-1.98) compared to children from schools with partial and poor cooperation (Mean DMFT=2.67:95%CI=2.10-3.23, and 2.69:95%CI=2.19-3.19, respectively). There were no significant differences in levels of knowledge, attitude and practices in oral health among the 3 groups of schools, but the proportion of good practices was highest in good cooperation schools compared to the schools with partial and poor cooperation to the OHPSP (41.3%, 27.3%, and 31.3%, respectively). Among 35 school directors, the majority of them (97.1%) believed that the OHPS program can reduce the dental caries prevalence among schoolchildren. Only 20.0% agreed that parents of schoolchildren should pay money to the school for tooth brushes and tooth paste of their children for brushing after lunch at school. The remaining answers were, they were uncertain (37.1%) and disagree (42.9%) that the school should have to manage that donated money. Among them, 82.9% reported that the OHPS Program activities did not disturb their time at school; 65% of them agreed there should be volunteers to help the schools in implementing the activities of the program. The majority of school directors (97.1%) thought that oral health examinations for schoolchildren were necessary. The results of the study suggested a need for continuous monitoring and strengthening of activities and cooperation of the Oral Health Preventive School Program among primary schools in Phnom Penh City to reduce the prevalence of dental caries among primary schoolchildren in Phnom Penh City, Cambodia.