To study the frequency of development of pneumonia, the specific features of its course and risk factors (RF) in inpatients with rheumatoid arthritis (RA).
The archival records (a total of 9059 case histories) of patients with RA treated at the Institute of Rheumatology, Russian Academy of Medical Sciences, during 7 calendar years (1994-1996, 2003-2006) were retrospectively studied. Case histories containing evidence for pneumonia sustained during the patient's hospital stay were selected for analysis. During the analysis, the authors took into account the clinical characteristics of RA, laboratory and X-ray parameters, and comorbidity, including pneumonia.
In the inpatients, the frequency of development of pneumonia was 0.8%. The risk factors of pneumonia were the high activity of RA, its systemic manifestations and no use of essential antirheumatic drugs. In 70% of RA patients developing pneumonia, the body temperature was normal or subfebrile; productive cough was absent in 50% of the patients; a third had no cough. Clear X-ray lung tissue infiltration was seen in 48% of cases. Clinical leukocytosis was absent in 50% of the patients; at the same time, there were statistically significant increases in the count of stab neutrophils and erythrocyte sedimentation rate.
The inpatients with RA develop pneumonia in about 0.8% of cases, which is characterized by an obliterated course and usually develops with the high activity of RA, its systemic manifestations and no use of essential antirheumatic drugs.