Background Neutropenia is an uncommon finding in the context of rheumatoid arthritis (RA). The incidence and association with RA features is not yet well-defined.
Objectives To determine the incidence and severity of neutropenia in an early RA inception cohort, explore possible association with RA features and describe its impact on patient's management.
Methods The Scottish Early Rheumatoid Arthritis (SERA) inception cohort prospectively recruited newly diagnosed RA patients (ACR-EULAR 2010 criteria), who were followed-up every 6 months. Patients who developed at least one episode of neutropenia (grade 1: <2000/μL, grade 2: <1500/μL, grade 3: <1000/μL, grade 4: <500/μL) were compared with patients who never developed neutropenia. Binominal logistic regression was performed, exploiting the enter model and using the occurrence of neutropenia as dependent variable.
Results 77 episodes of neutropenia were observed in 60 (8.6%) out of 698 RA patients, who were followed up for a median (range) time of 18 (6–48) months. Neutropenia occured in 12 (0–120) [median (range)] months after RA diagnosis. The majority had mild neutropenia (grade 1: n=49, grade 2: n=9, grade 3: n=0, grade 4: n=2) and the mean ± SD number of neutrophils/μL was 1.68±0.35. Of the 77 neutropenic episodes recorded, coexistent lymphopenia was found in 13.0%, leukopenia in 70.1%, thrombocytopenia in 1.3% and anaemia in 32.5%. At the time of the neutropenia, most of the patients were in remission (DAS28<2.6: 53%, DAS28<3.2: 15.5%, DAS28≤5.1: 22.4%, DAS28>5.1: 8.6%). Neutropenia was a single episode in the majority (76.7%) of the patients and led to treatment discontinuation in 11.7% of them.
Patients who subsequently developed neutropenia, were more likely females (p=0.03) and non-smokers (p=0.0009) (Table 1). Treatment received for RA was comparable between the two groups. Binominal regression analysis confirmed female gender [p=0.017, Exp(B): 2.587] and not smoking [p=0.032, Exp(B): 2.880] as predictors of neutropenia development.
During total follow-up time, patients who had at least one episode of neutropenia they also manifested more commonly anaemia (p=0.04) and lymphopenia (p=0.03). The rate of infections/1000 person-months did not differ between patients who developed neutropenia and those who did not [5.75 (2.47–11.33) vs 4.1 (3.13–5.47), p=0.399].
Conclusions Neutropenia was observed in about 9% of patients in this early RA cohort. It was usually mild, transient and not associated with increased infection rates. Interestingly, not-smoking and female gender were associated with neutropenia.
Disclosure of Interest None declared