AB1274 STIFF SPINE AND A WEAK HEART: A CASE OF LONG STANDING ANKYLOSING SPONDYLITIS DEVELOPING PULMONARY ARTERIAL HYPERTENSION SECONDARY TO MIXED CONNECTIVE TISSUE DISEASE, CONFERRING POOR PROGNOSIS

Background:Spondyloarthritides (SpA) and Connective Tissue Diseases (CTD) are considered distinct entities with diverse clinical features and genetic characteristics. There are very few case reports1of SpA coexisting with CTDs like Lupus, Scleroderma and Morphoea. Drugs used in treating SpA like Sulphasalazine and anti TNF drugs can also induce CTD.Objectives:We report a case of a patient with eleven years history of Ankylosing Spondylitis (AS), presenting with Mixed Connective Tissue Disease (MCTD) and Pulmonary Arterial Hypertension (PAH) constituting a therapeutic challenge.Methods:A 36 year old gentleman was diagnosed with AS at the age of 25 years, fulfilling the ASAS criteria (chronic inflammatory back pain, sacroiliitis on radiograph, HLAB27 positive). He was treated with NSAIDs, Sulphasalazine (SSZ) and physical therapy since 2008. There was gradual progression of his arthritis with high BASDAI along with recurrent anterior uveitis. He was treated with 5 doses of IV Infliximab 3mg/kg, between 2017 and early 2018. In May 2018, following further Infliximab he developed a serum sickness like reaction which was thought to be HACA response to Infliximab. He responded to IV hydrocortisone and antihistamines and Infliximab was discontinued.In February 2019 he developed severe flare up of peripheral arthritis. He was treated with Injection Adalimumab 40mg every 2 weeks along with Latent TB prophylaxis with Isoniazid and Rifampicin. He received 4 doses to no effect and was discontinued.In April 2019 Methotrexate (MTX) was added for peripheral arthritis. He discontinued both MTX and SSZ in July 2019 due to inefficacy. Peripheral arthritis responded well to Leflunomide that was started in September 2019.There was an unexpected turn of events in October 2019, when he was admitted with severe dyspnoea and cough with new onset raynauds, skin tightening over forearms and nape of neck with salt and pepper appearance of skin at these sites (Images). He was hypoxic requiring oxygen support. Echocardiogram showed moderate pericardial effusion and pulmonary hypertension (PASP 60mmHg), dilated right heart and pulmonary artery. Pulmonary embolism was excluded on a CT pulmonary angiogramFigure 1.Image 1, 2 – “salt and pepper” appearance of skin over the wrist and nape of neck, small joint arthritisFigure 2.Image 1, 2 – “salt and pepper” appearance of skin over the wrist and nape of neck, small joint arthritisResults:Investigations revealed 3+ ANA speckled pattern, anti RNP/ Sm 3+, Rheumatoid Factor negative. CRP 45.7u/l, Hemogram, renal and liver function tests were normal.Cardiac MRI showed minimal pericardial effusion with mildly dilated right ventricle, non-dilated left ventricle with LVEF (~44%).Right heart catheterization confirmed PAH with Mean PAP 58mmHg, LVEDP 8mmHg, PCWP 15mmHgA diagnosis of Mixed Connective Tissue Disease (MCTD) was made, associated with PAH and pericardial effusion.He was started on Ambrisentan and Tadalafil for PAH. Hydroxychloroquine and Mycophenolate Mofetil were also added in view of the PAH being associated with CTD. The additional pericardial effusion confers a poor prognosis.Conclusion:Association of Spondyloarthritides and Connective Tissue Disease is rare. There are very few case reports of their chance association, especially MCTD2. Our patient had been exposed to Sulphasalazine, Infliximab, Adalimumab and Isoniazid, all with a potential to induce an auto immune CTD. MCTD features have persisted despite drug withdrawal. This case may suggest routinely checking for ANA in SpA patients prior to initiating anti TNF drugs.References:[1]Brandt J, Maier T, Rudwaleit M et al. Co-occurrence of spondyloarthropathy and connective tissue disease: Development of Sjögren’s syndrome and mixed connective tissue disease (MCTD) in a patient with ankylosing spondylitis. Clinical and experimental rheumatology. 2002;20:80-4.[2]Lee JK, Jung SS, Kim TH, Jun JB, Yoo DH, Kim SY. Coexistence of ankylosing spondylitis and mixed connective tissue disease in a single patient. Clin Exp Rheumatol. 1999;17:263.Disclosure of Interests:None declared