ABSTRACT
OBJECTIVES: To evaluate the validity of the Ankylosing Spondylitis Disease Activity Score (ASDAS) in early spondyloarthritis (SpA) in comparison with conventional clinical measures of disease activity. METHODS: Six hundred and seventy-six incident cases of early SpA from the Esperanza programme were included. Patients were categorised into high and low disease activity states based on patient and physician global assessment scores and on the physician's decision to start treatment with a disease-modifying antirheumatic drug or tumour necrosis factor blocker. The discriminant ability of ASDAS-C-reactive protein (CRP) and ASDAS-erythrocyte sedimentation rate (ESR) was tested using standardised mean differences between patients with high and low disease activity. Convergent validity was tested by Pearson correlation between ASDAS versions and other measures of disease activity. RESULTS: ASDAS-ESR and ASDAS-CRP showed good correlation with BASDAI (r=0.79 and 0.74, respectively). Both indices correlated well with the patient global assessment (r=0.70 in both indices) and moderately with the physician global score (r=0.46 and 0.47, respectively). CRP and ESR showed poor correlation with patient- and physician-derived measures. ASDAS performed similarly across the global SpA sample, ankylosing spondylitis (AS), non-radiographic axial SpA and peripheral SpA. CONCLUSIONS: ASDAS performed as a valid activity score even being slightly better than the Bath Ankylosing Spondylitis Disease Activity Index in its ability to discriminate between high and low disease activity in early SpA. ASDAS performed similarly in AS, early forms of SpA, non-radiographic axial SpA and peripheral SpA.
Subject(s)
Spondylitis, Ankylosing/diagnosis , Adult , Back Pain/diagnosis , Blood Sedimentation , C-Reactive Protein/analysis , Early Diagnosis , Female , Humans , Male , Reproducibility of Results , Severity of Illness Index , Spondylitis, Ankylosing/blood , Spondylitis, Ankylosing/physiopathology , Surveys and Questionnaires , Time FactorsABSTRACT
Several karyotypic forms have been previously described in populations of the vole species Microtus thomasi from Greece. In particular, the karyomorphs Microtus thomasi 'thomasi' and 'atticus' differ in X chromosome morphology, being acrocentric and subtelocentric, respectively. Furthermore, remarkable heterochromatin content variability has been described in sex chromosomes of both karyomorphs. Genomic DNA digestion with AluI allowed us to clone an 884 bp long repeated DNA sequence (Mth-Alu900) from the karyomorph M. thomasi 'atticus'. This repeated DNA is AT rich and seems to be organized mainly as a dimer of the 884-bp unit, which presents three simple repeats (CAAAT, CAGAT and CAGAC) that constitute 80% of the total unit length. This repeated DNA is exclusive to M. thomasi, since it is absent from the genome of other studied Arvicolinae species. The chromosomal location of Mth-Alu900 was analyzed on M. thomasi 'thomasi' and M. thomasi 'atticus' karyomorphs, with different sex chromosome constitution. It was mainly located on the pericentromeric heterochromatin of most autosomes and X chromosomes on both karyomorphs. Results are also discussed in relation to karyotypic and sex chromosome variations in M. thomasi. To our knowledge, Mth-Alu900 constitutes a new - the third discovered so far - pericentromeric repeated DNA sequence described in Microtus species.
Subject(s)
Repetitive Sequences, Nucleic Acid/genetics , X Chromosome/genetics , Y Chromosome/genetics , Alu Elements , Animals , Arvicolinae/genetics , Base Sequence , Centromere/genetics , Chromosome Banding , DNA/genetics , DNA/isolation & purification , Genome , Greece , In Situ Hybridization, Fluorescence , Karyotyping , Molecular Sequence Data , Sequence AlignmentABSTRACT
The chromosomal distribution of mobile genetic elements is scarcely known in Arvicolinae species, but could be of relevance to understand the origin and complex evolution of the sex chromosome heterochromatin. In this work we cloned two retrotransposon sequences, L1 and SINE-B1, from the genome of Chionomys nivalis and investigated their chromosomal distribution on several arvicoline species. Our results demonstrate first that both retroelements are the most abundant repeated DNA sequences in the genome of these species. L1 elements, in most species, are highly accumulated in the sex chromosomes compared to the autosomes. This favoured L1 insertion could have played an important role in the origin of the enlarged heterochromatic blocks existing in the sex chromosomes of some Microtus species. Also, we propose that L1 accumulation on the X heterochromatin could have been the consequence of different, independent and rapid amplification processes acting in each species. SINE elements, however, were completely lacking from the constitutive heterochromatin, either in autosomes or in the heterochromatic blocks of sex chromosomes. These data could indicate that some SINE elements are incompatible with the formation of heterochromatic complexes and hence are necessarily missing from the constitutive heterochromatin.
