Prevalence of the American College of Rheumatology classification criteria in a group of 162 systemic lupus erythematosus patients from Croatia.

Aim: To identify systemic lupus erythematosus (SLE) patients diagnosed and treated at the outpatient clinic of our Division fulfilling at least four American College of Rheumatology (ACR) classification criteria at the time of the study, to determine the prevalence of each of the criteria at three different time points, and to compare the data with similar studies.

Methods: We performed retrospective and descriptive analysis of medical records of 162 patients fulfilling at least 4 ACR criteria. Classification criteria were counted and the frequency of each criterion was identified at three different time points: disease onset, time of diagnosis, and the time when the study was conducted.

Results: At diagnosis and at the time when the study was conducted there were 3.8 and 5.4 fulfilled classification criteria, respectively. The most common criterion at the time of the disease onset was arthritis (52.6%); at the time of diagnosis it was positive antinuclear antibody (ANA) titer (88.0%); and at the time when the study was conducted it was positive ANA titer (95.7%), immunologic disorder (89.5%), arthritis (71.0%), hematologic disorder (70.4%), malar rash (61.7%), and photosensitivity (51.9%).

Conclusion: The prevalence of ACR criteria in our patients is similar to that in other studies, especially those involving Caucasian patients. Our results confirm the value of the ACR criteria in patients with an already established diagnosis. This is the first study on the prevalence of disease manifestations among Croatian patients with SLE.