Can some cases of ‘possible’ spondyloarthropathy be classified as ‘definite’ or ‘undifferentiated’ spondyloarthropathy?Value of criteria for spondyloarthropathies

From Retrospective Analysis of Patients with Undifferentiated Spondyloarthritis (SpA) to Analysis of Prospective Cohorts and Detection of Axial and Peripheral SpA

“…In the Schattenkirchner and Krüger study 24 , the percentage reached 25% within 2 to 6 years, versus Huerta-Sil's finding of 42% by 3 years after symptom onset 25 . Two further studies 16,26 found AS in 25% and 36% by 5 years after onset. Few followup studies reached 10 years or more.…”

“…Diagnosis varied from "HLA-B27-negative associated oligoarthritis" 24 to "possible ankylosing spondylitis" 16 , "possible SpA" 26 , and "undifferentiated SpA" 17,22,25 . Disease duration in various studies extended more than 10 years (i.e., the sum of the duration of the disease at baseline and the duration of followup); therefore, diagnosis of USpA does not necessarily mean early or recent SpA.…”

“…Fulfillment of AS criteria 21 by patients with USpA in the course of disease has been inconsistently associated with baseline characteristics, specifically uveitis 16,25,26 , HLA-B27 16,22 , alternate gluteal pain 22 , peripheral arthritis 23 , high erythrocyte sedimentation rate 16 , or C-reactive protein (CRP) 25 , recurrent oligoarthritis 24 , and low-grade radiographic sacroiliitis 25 . However, only the reports by Huerta-Sil, et al 25 …”

The assessment of the spondyloarthritis international society concept and criteria for the classification of axial spondyloarthritis and peripheral spondyloarthritis: A critical appraisal for the pediatric rheumatologist

“…These include uveitis [41,46,48], HLA-B27 [41,43], alternate gluteal pain [43], peripheral arthritis [44], a high erythrocyte sedimentation rate [41], an elevated C- reactive protein (CRP) [46], recurrent oligoarthritis [45], and a low-grade radiographic sacroiliitis [46]. AS risk factors include low-grade radiographic sacroiliitis [46,62] and uveitis [46], and buttock pain [47].…”

Diagnose und Fr�hdiagnose der ankylosierenden Spondylitis (Morbus Bechterew)

“…Eine spanische Studie zum diagnostischen Einsatz der ESSG-Kriterien bei Patienten mit einer möglichen SpA und kurzer Krankheitsdauer ergab jedoch einen positiven prädiktiven Wert von nur 46,6%. Mit anderen Worten, etwa jeder zweite Patient mit einer möglichen SpA, der die ESSG-Kriterien erfüllte, hatte nach 5 Jahren Nachbobachtung aus Sicht des Rheumatologen keine SpA mehr [8]. Dies muss als Hinweis auf eine unzureichende Spezifität der ESSG-Kriterien interpretiert werden, die sich somit als nicht optimal für die Diagnosestellung bei frühen Fällen erweisen.…”