AB0150 IMMATURE GRANULOCYTES LEVEL IS A POTENTIAL BIOMARKER IN PERIPHERAL ENTHESITIS
Authors: Atheer Al-Ansari, Iman Hussein
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Immature granulocytes (IG) level in peripheral blood is used as early sign of infection. On the other hand, IG could be elevated in other conditions like inflammatory or cancerous diseases and in pregnancy. Similar to CRP, we have observed a series of cases of peripheral enthesitis associated increased level of IG and correlated with CRP elevation and clinical activity. <h3>Objectives:</h3> To test the concept of IG as a biomarker in peripheral enthesitis, This observation might be a reflection to the innate immunity role in pathogenesis of enthesitis. <h3>Methods:</h3> We have identified 13 cases over the last 12 months at the Rheumatology clinic in our centre who have shared two features (clinical enthesitis and elevated IG) those 13 cases are mainly presented with recurrent foot and ankle pain and swelling of enthesitis nature. <h3>Results:</h3> The cohort is of equal gender distribution 46/54% respectively and age range 31-53 years (mean age 38.5), only 3 patients are known to have Psoriatic arthritis whilst the rest either undiagnosed or diagnosed Rheumatoid arthritis or gout prior to clinic visit. The rheumatologist clinical diagnoses are of enthesitis of foot, ankle, knee and hip area as shown on the table [1] apart from one patient who has spinal symptoms mainly. 4/13 patients have the history of psoriasis and after their visits we find them fit in the CASPAR criteria for psoriatic arthritis. All these cases are associated with increased absolute number of IG as well as differential (IG) number compare to 10/13 of these cases are having high CRP. The 3 cases with normal CRP do have relatively slight increase in (IG) number. The main correlation is of response to therapy and was seen in 7 cases who have followed up at the time of submission and it shows a 100% correlation between CRP, absolute (IG) and differential (IG) values. There are 3 patients who have elevated (IG) but normal CRP and it would possible indicate (IG) test has a better yield than CRP in peripheral enthesitis. <h3>Conclusion:</h3> Immature granulocytes can be elevated in inflammatory disease and more notably in peripheral enthesitis of the lower limbs of inflammatory rather than mechanical nature and do correlate with CRP elevation as well as response to therapy. Larger studies are needed to assess the usefulness and validity of (IG) level in clinical practice. <h3>References</h3> [1] Rudwaleit Met al, The Assessment of SpondyloArthritis International Society classification criteria for peripheral spondyloarthritis and for spondyloarthritis in genera, Ann Rheum Dis. 2011;70(1):25 [2] Moots Ret al, Low-density granulocytes: functionally distinct, immature neutrophils in rheumatoid arthritis with altered properties and defective TNF signaling, Translational &amp; Clinical Immunology 2016 https://doi.org/10.1189/jlb.5A0116-022R [3] Salvarani c et al, Isolated peripheral enthesitis and/or dactylitis: a subset of psoriatic arthritis. J Rheumatol. 1997 Jun;24(6):1106-10 <h3>Disclosure of Interests:</h3> None declared