Serum N-propeptide of collagen IIA (PIIANP) as a marker of radiographic osteoarthritis burden.

OBJECTIVE: Cartilage homeostasis relies on a balance of catabolism and anabolism of cartilage matrix. Our goal was to evaluate the burden of radiographic osteoarthritis and serum levels of type IIA procollagen amino terminal propeptide (sPIIANP), a biomarker representing type II collagen synthesis, in osteoarthritis. METHODS: OA burden was quantified on the basis of radiographic features as total joint faces with an osteophyte, joint space narrowing, or in the spine, disc space narrowing. sPIIANP was measured in 1,235 participants from the Genetics of Generalized Osteoarthritis study using a competitive enzyme-linked immunosorbent assay. Separate multivariable linear regression models, adjusted for age, sex, and body mass index and additionally for ipsilateral osteophytes or joint/disc space narrowing, were used to assess the independent association of sPIIANP with osteophytes and with joint/disc space narrowing burden in knees, hips, hands and spine, individually and together. RESULTS: After full adjustment, sPIIANP was significantly associated with a lesser burden of hip joint space narrowing and knee osteophytes. sPIIANP was associated with a lesser burden of hand joint space narrowing but a greater burden of hand osteophytes; these results were only evident upon adjustment for osteoarthritic features in all other joints. There were no associations of sPIIANP and features of spine osteoarthritis. CONCLUSIONS: Higher cartilage collagen synthesis, as reflected in systemic PIIANP concentrations, was associated with lesser burden of osteoarthritic features in lower extremity joints (knees and hips), even accounting for osteoarthritis burden in hands and spine, age, sex and body mass index. These results suggest that pro-anabolic agents may be appropriate for early treatment to prevent severe lower extremity large joint osteoarthritis.

Rheumatoid arthritis-associated polymorphisms at 6q23 are associated with radiological damage in autoantibody-positive RA.

OBJECTIVE: Recent studies have identified 6q23 as an important susceptibility locus for rheumatoid arthritis (RA), with risk alleles at 3 single-nucleotide polymorphisms combining to give an effect size greater than that of these markers individually. We investigated whether these polymorphisms are also associated with disease severity measured by radiological damage. METHODS: We studied 927 patients from a cross-sectional RA cohort. Median Larsen scores (LS) read from radiographs taken at study entry were compared by genotype at rs6920220, rs13207033, and rs5029937 according to a dominant model using negative binomial regression with stratification for autoantibody status. RESULTS: Median LS was associated with genotype at rs6920220 [LS 31 GG vs 36 GA/AA (p=0.02) in cyclic citrullinated peptide+ (CCP) RA] and rs13020220 [LS 37 GG vs 29 GA/AA (p=0.02) in CCP+ RA] only in autoantibody-positive RA, with no association at rs5029937. Association was stronger for these markers in combination [LS 28 vs 42 for lowest vs highest risk genotype combination in rheumatoid factor positivity (p=0.007), LS 28 vs 37 for anti-CCP+ (p=0.01)]. CONCLUSION: Established RA risk markers at 6q23 are associated also with radiographic severity in autoantibody-positive RA; as for susceptibility, the association for these markers in combination is stronger than that for markers alone.

Haemopoietic stem cell transplantation--an evolving treatment for severe autoimmune and inflammatory diseases in rheumatology, neurology and gastroenterology.

The concept of haemopoietic stem cell transplantation (HSCT) to treat severe autoimmune diseases has been around for several decades. Advances in the safety of HSCT have made it a clinical reality since 1995. Databases have registered around a thousand patients treated specifically for a wide range of diseases, predominantly multiple sclerosis (MS), systemic sclerosis (SSc), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Phase I/II prospective and retrospective studies have supported the potential of autologous HSCT as a treatment option in severely affected patients, with profound and prolonged clinical responses in some diseases, although procedures are generally not curative. Allogeneic HSCT appears to offer curative potential, but the potential of high toxicity has limited its use in this context. The exact role of HSCT remains to be defined, particularly in the context of other advances in the treatment of autoimmune disease. Along with other groups, the European Group for Blood and Marrow Transplantation (EBMT) are overseeing several phase III trials in autologous transplantation. Given the risks of the HSCT, eligibility is restricted to patients who have severe, treatment resistant disease, in whom the prognosis is otherwise poor. This review aims to summarise the current published data in this evolving treatment for relatively rare patients with resistant or rapidly progressive disease where treatment options are otherwise limited. This cross-fertilization of knowledge between many specialties may provide increasing therapeutic opportunities in otherwise untreatable diseases. Moreover, destroying and rebuilding immune systems may provide insights into autoimmune diseases.