Etanercept for Sacroiliitis in MCTD like skin thickening, or pulmonary hypertension.13 Arthritis in MCTD patients is responsive to NSAIDs, hydroxychloroquine, and/ or low-dose corticosteroids. Our patient with mild and nonerosive polyarthritis had significant improve- ment following combination therapy. Patients with more destructive and erosive arthritis may require more aggressive therapies, including methotrexate, leflunomide, or azathioprine.13 Data on TNF-α blockers efficacy and safety have been recognized for multiple diseases with inflammatory peripheral arthritis or axial arthritis /spondylitis, including RA and AS.7,8,14 Treatment has been associated with diverse autoimmune toxicities, including anti-double-stranded DNA antibody induction and development of systemic, lupus-like syndromes or a cutaneous, lupus-like rash, although the etiology of aberrant immune responses it is not clearly understood.15 We proposed that our patient with MCTD and bilateral refractory sacroiliitis unresponsive to NSAIDs and intraarticular steroid injections may do well with TNF-α blocker therapy, as do AS patients. However, two reports previously described development of a lupus-like syndrome in MCTD patients.5,6 In this case we used etanercept with good result, and without occurrence of clinical features consistent with lupus-like syndrome, such as myalgia, fever, arthralgia, or skin rash. As our patient had MRI scanning at 18 months, it is impossible to predict time of sacroiliac lesion improvement. However, a German study group found significant regression on MRI of active sacroiliitis following 6 weeks of treatment.16 For more accurate assessment, periodic MRI ex- amination, development of an MRI scoring system, and standardized dosing and duration of etanercept in a large population study would be required. We report safe and effective use of etanercept for sacroiliitis in a patient with MCTD with evidence of symptomatic and radiological im- provement. The results of these few case reports show that there may be efficacy in the use of anti-TNF therapy in MCTD-related polyarthritis. If used, patients should be warned of the risk of development of a lupus-like syndrome. REFERENCES 1. Sharp GC, Irvin WS, Tan EM, Gould RG, Holman HR. Mixed connective tissue disease--an apparently distinct rheumatic disease syndrome associated with a specific antibody to an extractable nuclear antigen (ENA). Am J Med 1972;52:148-59. 2. Alarcón-Segovia D, Cardiel MH. Comparison between 3 diagnostic criteria for mixed connective tissue disease. Study of 593 patients. J Rheumatol 1989;16: 328-34. 3. 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. 4. Brandt J, Maier T, Rudwaleit M, Kühl U, Hiepe F, Sieper J, 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. Clin Exp Rheumatol 2002;20:80-4. 5. Richez C, Blanco P, Dumoulin C, Schaeverbeke T. Lupus erythematosus manifestations exacerbated by etanercept therapy in a patient with mixed connective tissue disease. Clin Exp Rheumatol 2005;23:273. 6. Christopher-Stine L, Wigley F. Tumor necrosis factor- alpha antagonists induce lupus-like syndrome in patients with scleroderma overlap/mixed connective tissue disease. J Rheumatol 2003;30:2725-7. 7. Braun J, Brandt J, Listing J, Zink A, Alten R, Golder W, et al. Treatment of active ankylosing spondylitis with infliximab: a randomised controlled multicentre trial. Lancet 2002;359:1187-93. 8. Brandt J, Khariouzov A, Listing J, Haibel H, Sörensen H, Grassnickel L, et al. Six-month results of a double- blind, placebo-controlled trial of etanercept treatment in patients with active ankylosing spondylitis. Arthritis Rheum 2003;48:1667-75. 9. van der Linden S, Valkenburg HA, Cats A. Evaluation of diagnostic criteria for ankylosing spondylitis. A proposal for modification of the New York criteria. Arthritis Rheum 1984;27:361-8. 10. Alarcon-Segovia D, Villareal M. Classification and diagnostic criteria for mixed connective tissue disease. In: Kasukawa R, Sharp GC, editors. Mixed Connective Tissue Disease and Anti-nuclear Antibodies. Amster- dam: Elsevier; 1987. p.33-40. 11. Brandt J, Rudwaleit M, Eggens U, Mertz A, Distler A, Sieper J, et al. Increased frequency of Sjögren's syndrome in patients with spondyloarthropathy. J Rheumatol 1998;25:718-24. 12. Scotto di Fazano C, Grilo RM, Vergne P, Coyral D, Inaoui R, Bonnet C, et al. Is the relationship between spondyloarthropathy and Sjögren's syndrome in women coincidental? A study of 13 cases. Joint Bone Spine 2002;69:383-7. 13. Kim P, Grossman JM. Treatment of mixed connective Yonsei Med J Vol. 49, No. 1, 2008