1Rheumatologist, Rheumatic Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
2Pulmonologist, Lung Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
3Internist, Rheumatic Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Introduction: Systemic Lupus Erythematosus (SLE) is an autoimmune disease affect nearly every organ system. Pulmonary involvement, which is a common manifestation of SLE, can remain undiagnosed if asymptomatic. This study aimed to evaluate the efficiency of spirometric findings in early detection of silent pulmonary involvement and examine its correlation with the six minute walk test in SLE patients. Materials and Methods: In this cross-sectional study fifty patients, who met the American College of Rheumatology criteria for SLE, were recruited from the outpatient rheumatology clinic at the Imam Reza Hospital of Mashhad between July 2013 and September 2014. First, a checklist including demographic information and previous medical documents was completed. Then, spirometry and 6MWT was performed to evaluate subclinical pulmonary involvement and assess patients’ exercise capacity. Results: Based on the results of pulmonary function tests, patients were divided into two groups. A total of 40 patients with normal pattern were placed in one group and 10 patients with restrictive pattern in the other. The difference between SLE patients with and without abnormal spirometry were statistically significant in regard to anti-RNP positivity but total distance walked in six minute, was not significantly different between two groups (p=0.356). Additionally, there were no significant correlations between 6MWD and FVC in SLE patients in the either group as determined by Pearson’s correlation coefficient testing. (R=0.439,P=0.205 in SLE patients with normal spirometry and R=0.191,P=0.237 in those with abnormal pattern) Conclusion: Considering the impact of anti-U1RNP positivity with restrictive pattern on spirometry, it can be deemed as a pulmonary involvement predictor in SLE patients. However, lack of correlation between 6MWT and spirometric parameters is suggestive of restrictive lung involvement, which in turn, demonstrates a multifactorial basis for limited exercise capacity in patients with SLE. Thus, the application of the 6MWT as a measure of pulmonary function is called into question.
1. Gross M, Esterly JR,. Earle RH, Pulmonary alterations in systemic lupus erythematosus, Am Rev Respir Dis 1982;105:572–7.
2. Torre O, Harari S. Pleural and pulmonary involvement in systemic lupus erythematosus. Presse Med 2011;40: 19–29.
3. Segal AM, Calabrese LH, Ahmad M, Tubbs RR, White CS. The pulmonary manifestations of systemic lupus erythematosus. Semin. Arthritis Rheum 1985;14:202–24.
4.Nakano M, Hasegawa H, Takada T, Ito S, Muramatsu Y, Satoh M, et al. Pulmonary diffusion capacity in patients with systemic lupus erythematosus. Respirology 2002;7:45–9.
5. Silberstein SL, Barland P, Grayzel AI, Koerner SK. Pulmonary dysfunction in SLE: prevalence, classification and correlation with other organ involvement. J Rheumatol 1980;7:187–95.
6. Chick TW, De Horatius RJ, Skipper BE, Messner RP. Pulmonary dysfunction in systemic lupus erythematosus without pulmonary symptoms. J Rheumatol 1976;3:262–68.
7.Trapani S, Camiciottoli G, Ermini M, Castellani W, Falcini F. Pulmonary involvement in juvenile systemic lupus erythematosus: a study on lung function in the patients asymptomatic for respiratory disease. Lupus 1998; 7:545–50.
8.Rolla G, Brussino L, Bertero MT, Bucca C, Converso M. Respiratory function in systemic lupus erythematosus: relation with activity and severity. Lupus 1996;5: 38–43.
9. PQ Eichacker, K Pinsker, A Epstein, J Schiffenbauer, A Grayzel. Serial pulmonary testing in patients with SLE. Chest 1988;94:129–32.
10.Villalba WO, Sampaio-Barros PD, Pereira MC, Cerqueira EM, Leme CA Jr, Marques-Neto JF, et al. Six-minute walk test for the evaluation of pulmonary disease severity in scleroderma patients. Chest 2007;131:217-22.
11.Tan EM, Cohen AS, Fries JF, Masi AT, McShane DJ, Rothfield NF, et al. The 1982 revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum 1982;25:1271–7.
12.Golshan M, Nematbakhsh M, Amra B, Crapo RO. Spirometric reference values in a large middle eastern population. Eur Respir J 2003;22:529–34.
13. Gardner RM, Hankinson JL, West BJ, Evaluating commercially available spirometers, Am Rev Respir Dis1980; 121:73–82.
14. American Thoracic Society, Standardization of spirometry 1987 update, Am. Rev. Res. Dis. 1987;136:1285–98.
15.Ferguson GT, Enright PL, Buist AS, Higgins MW. Office spirometry for lung health assessment in adults: A consensusstatement from the National Lung Health Education Program. Chest 2000;117:1146-9.
16.American Thoracic Society statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002;166:111–7.
17.Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982;14:377-81.
18. Solway S, Brooks D, Lacasse Y, Thomas S. A qualitative systematic overview of the measurement properties of functional walk tests used in the cardiorespiratory domain. Chest 2001;119:256–270.
19. Khandelwal MK, Maheshwari VD, Garg S, KumarK, Gupta R, Khandelwal S. Six minute walk distance: Correlation with spirometric & clinical parameters in chronic obstructive pulmonary disease. Int J. Healthc Bio Res 2013;3:217-226.
20.Leite MA, Pereira MC, Costallat LT, Villalba WO, Moreira MM, Paschoal IA. Evaluation of respiratory impairment in patients with systemic lupus erythematosus with the six-minute walk test. Rev Bras Reumatol 2014;54: 192-9.
21. Naghshin R, Zaker MM, Ehteshami Afshar A. Association between Six-Minute Walk Test and Expiratory Spirometry Parameters in Chronic Obstructive Pulmonary Disease. J Tehran Heart Cent 2005;6(3):59-63.
22.Buch MH, Denton CP, Furst DE, GueilevinL, Rubin L, Wells LU, et al. Submaximal exercise testing in the assessment of interstitial lung disease secondary to systemic sclerosis: reproducibility and correlations of the 6-min walk test. Ann Rheum Dis 2007; 66:169-73.
23. Xia YK, Tu SH, Hu YH, Wang Y, Chen Z, Day HT, et al. Pulmonary hypertension in systemic lupus erythematosus: a systematic review of 642 cases in Chinese population. Rheumatol Int 2013;33:1211-7.
24.Tashkin D, Ellashoff R, Clements PJ, Goldin J,Roth MD, Furst DE, etal. The scleroderma lung study:oral cyclophosphamide versus placebo for the treatment of scleroderma related interstitial lung disease. N Engl J Med 2006;35:2655-66
25. Rosa R, Santos AS, Celho R, Maia D, Borba A, Goncalves I, et al. The relation of six-minute walk test and lung functioning in interstitial lung disease. ERJ 2013;42(suppl 57):2353-59.
26. Chen H, Liang BM, Tang YJ, Xu ZB, Wang K, Yi O, et al. Relationship between six-minute walk test and pulmonary function test in stable chronic obstructive pulmonary disease with different severities. Chin Med J 2012;125:3053-8.