CÓRDOBA, Spain—Low back pain, sacroiliitis, and limb arthritis are all early signs of spondyloarthritis (SpA), according to new data from the REGISPONSER-Early inception cohort that appears in the April issue of Rheumatology.1
Our study highlights the need to define the initial stages of SpA, and to carry out a close follow-up of these cohorts to expand our knowledge of the course and prognosis of this condition and to determine the response to treatment,” conclude the researchers who were led by Marena Rojas-Vargas, MD, a rheumatologist at Hospital Universitario Reina Sofía in Córdoba, Spain.
The new study comprised a sub-group of 150 SpA patients from an initial 2,367 patients included in the national registry of spondyloarthropathies (REGISPONSER). The patients included in the new cohort had a disease course of two years or less from the onset of symptoms or appearance of the first signs of their disease.
Of the 150 participants, 46 SpA patients had ankylosing spondylitis (AS), 51 had psoriatic spondyloarthritis (Ps-SpA), 43 had undifferentiated spondyloarthropathy (uSpA), 5 had reactive arthritis (ReA), 4 had inflammatory bowel disease arthropathy (IBD arthropathy), and 1 had juvenile chromic arthritis (JCA).
Back pain most frequent symptom overall
The most frequent early signs or symptoms of SpA were back pain, which affected 72% of AS patients and 56% of uSpA patients. Moreover, lower limb arthritis was the first symptom in 57% of Ps-SpA patients, 35% uSpA patients and 20% AS patients. Upper limb arthritis was the first symptom in 53% of Ps-SpA patients and <16% of the remaining patients, the study showed.
AS patients with early disease reported upper limb arthritis more frequently than their counterparts with a longer disease duration. In addition, uSpA patients with early disease reported more enthesitis than patients with longer disease duration. All AS patients showed early radiological sacroiliitis. Of these, 54% had Grade II, 39% had Grade III, and 7% had Grade IV radiological sacroiliitis, the study showed.
Differences in age of onset by SpA type
Patients in the Ps-SpA group developed the disease about 12 years later than their counterparts with AS and uSpA, the study showed. The age at onset was also higher in the entire early cohort, when compared to the age at onset in the REGISPONSER-Late cohort.
“Although we may consider that patients could present with vague symptoms, unclear or poorly thought spondylitis many years before, here with this early assessment of the beginning of the disease and diagnosis we could assume that we are avoiding or minimizing the memory bias and that patients could remember their first symptoms better,” the researchers point out.
Early spondyloarthritis: Translating research into practice
The study found a relatively high frequency of radiographic sacroiliitis (about 42%) after only 2 years of symptoms and the relatively high mean age (around 39 years) at symptom onset in the AS group, points out Walter P. Maksymowych, FRCPC, a professor of medicine and consultant rheumatologist at the University of Alberta, in Edmonton, Canada.
"This suggests that disease may be more rapidly progressive than originally thought and/or there may be selection for a group of patients with a relatively long asymptomatic phase in this cohort of Spanish patients," he told MSKreport.com.
"In my practice the mean age at onset of symptoms is much lower. However, a substantial proportion of my patients do already have radiographic disease at presentation in agreement with the study's findings."