Childhood-onset systemic lupus erythematosus: A descriptive and comparative study of clinical, laboratory, and treatment characteristics in two populations.

OBJECTIVE: The aim of this study was to characterize childhood-onset systemic lupus erythematosus (SLE) in two large cohorts from Turkey and the United States. METHODS: Patients diagnosed with childhood-onset SLE who fulfilled the 1997 American College of Rheumatology classification criteria for SLE from four reference centers in Turkey and the University of Pittsburgh School of Medicine in the United States were included in this study. A comparative analysis was conducted to evaluate the similarities and differences in clinical and laboratory features, damage accrual, and treatment experiences between the two populations. RESULTS: A total of 174 patients with childhood-onset SLE were included in this study (108 patients from Turkey and 66 patients from the United States). The female-to-male ratio was similar between the two cohorts (∼3:1, p = .73). The median age at diagnosis was 11.67 years (2.19-17.93) in the Turkish cohort and 13.68 years (2.74-17.93) in the U.S. cohort (p < .001). Photosensitivity (45.4% and 21.2%; p = .007) and renal involvement (41.7% and 36.4%; p = .045) were higher in the Turkish cohort. Anti-Ro/SSA (34.8% and 15.7%; p < .001), anti-Sm (59.1% and 19.4%; p < .001), and anti-RNP (47.0% and 14.8%; p < .001) positivity was more frequent in the U.S. cohort. Current use of rituximab (37.9% and 1.9%; p < .001) and belimumab (19.7% and 0%; p < .001) was more prevalent in the U.S. cohort, while the use of cyclophosphamide (often according to the low dose Euro-Lupus protocol) throughout the disease course (24.1% and 4.5%; p < .001) was more frequent in the Turkish cohort. SLICC/ACR Damage Index scores were not different between the two cohorts. CONCLUSION: This study provides detailed clinical and laboratory features of childhood-onset SLE in two independent and geographically divergent cohorts. Our findings suggest an earlier age of disease onset and a higher prevalence of kidney involvement in Turkish patients. Differences in treatment approaches were also noted. However, damage accrual related to SLE does not appear to be different between the two patient populations.

Not easy-peasy to diagnose: familial Mediterranean fever unaccompanied by fever.

Classical attacks of familial Mediterranean fever (FMF) are often accompanied by fever, but some of the patients have attacks without fever. This study aimed to compare the characteristics of FMF patients with and without fever during their attacks and draw attention to the different clinical presentations of FMF in children. Medical files of patients aged 0-18 years who were followed up with the diagnosis of FMF in two reference pediatric rheumatology centers were reviewed retrospectively. The patients were divided into two groups: children who had had no fever in any of their attacks were assigned as group 1, and those who had fever during their attacks were classified as group 2. Out of 2003 patients evaluated, 191 (9.53%) patients had attacks not accompanied by fever and their median age at onset of symptoms (7.0 vs. 4.0 years, p < 0.001) and the median age at diagnosis (8.6 vs. 6.0 years, p < 0.001) were significantly higher; however, group 2 had a delay in diagnosis. The annual number of attacks and abdominal attacks were more common in group 2; arthritis, arthralgia, erysipelas-like rash, exercise-induced leg pain, and myalgia were more common in group 1.    Conclusion: The data from the assessment of children with FMF attacks not accompanied with fever were presented for the first time. Children with late age onset of FMF and dominance of musculoskeletal features may display attacks not accompanied with fever. What is Known: • Familial Mediterranean fever (FMF) is the most common inherited auto-inflammatory disease, characterized by recurrent attacks of fever, serositis, and musculoskeletal symptoms. • Although fever is the most common symptom, few studies have reported attacks without fever. What is New: • The aim of this study was to identify patients with FMF but without fever during attacks and to demonstrate their distinctive presentations. • We found that 7% of our patients had afebrile attacks with predominant musculoskeletal symptoms and were diagnosed earlier than patients with febrile attacks, probably due to early referral to pediatric rheumatology clinics.