Sjögren's syndrome: An underdiagnosed condition in mixed connective tissue disease

OBJECTIVE

To determine the prevalence of sicca symptoms, dry eye, and secondary Sjögren's syndrome and to evaluate the severity of dry eye in patients with mixed connective tissue disease.

METHODS

In total, 44 consecutive patients with mixed connective tissue disease (Kasukawa's criteria) and 41 healthy controls underwent Schirmer's test, a tear film breakup time test, and ocular surface staining to investigate dry eye. In addition, the dry eye severity was graded. Ocular and oral symptoms were assessed using a structured questionnaire. Salivary gland scintigraphy was performed in all patients. Classification of secondary Sjögren's syndrome was assessed according to the American-European Consensus Group criteria.

RESULTS

The patients and controls had comparable ages (44.7±12.4 vs. 47.2±12.2 years) and frequencies of female gender (93 vs. 95%) and Caucasian ethnicity (71.4 vs. 85%). Ocular symptoms (47.7 vs. 24.4%) and oral symptoms (52.3 vs. 9.7%) were significantly more frequent in patients than in controls. Fourteen (31.8%) patients fulfilled Sjögren's syndrome criteria, seven of whom (50%) did not have this diagnosis prior to study inclusion. A further comparison of patients with mixed connective tissue disease with or without Sjögren's syndrome revealed that the former presented significantly lower frequencies of polyarthritis and cutaneous involvement than did the patients without Sjögren's syndrome. Moderate to severe dry eye was found in 13 of 14 patients with mixed connective tissue disease and Sjögren's syndrome (92.8%).

CONCLUSIONS

Sjögren's syndrome, particularly with moderate to severe dry eye, is frequent in patients with mixed connective tissue disease. These findings alert the physician regarding the importance of the appropriate diagnosis of this syndrome in such patients.

The frequency of anti-β2-glycoprotein I antibodies is low and these antibodies are associated with pulmonary hypertension in mixed connective tissue disease

The objective of this study is to evaluate the prevalence of antiphospholipid antibodies, mainly anti-β2-glycoprotein I (anti-β2-GPI), and their possible clinical and laboratory relevance in mixed connective tissue disease (MCTD). This study included 39 consecutive patients with MCTD (Kasukawa’s criteria) from January, 2005, to March, 2007, and compared them with 21 age- and sex-matched healthy controls. IgG and IgM anticardiolipin (aCL) and anti-β2-GPI were measured by ELISA. Lupus anticoagulant (LA) was detected by functional coagulation tests. Medium to high titres of aCL and anti-β2-GPI antibodies were found in sera from four (10.2%) MCTD patients. One of these patients was found to be positive for IgM aCL, IgM anti-β2-GPI and LA antibodies simultaneously. Additionally, this patient had a previous history of foetal loss in the second trimester and new-onset pulmonary arterial hypertension (PAH). The other three patients had none of the manifestations of antiphospholipid syndrome (APS) or PAH. The mean value of IgG anti-β2-GPI was higher among those MCTD patients with PAH than in the group without PAH (34.2 ± 46.8 vs 12.3 ± 9.1, P = 0.018). None of the controls were positive for antiphospholipid antibodies. High to moderate titres of anti-β2-GPI as well as APS were rare in MCTD, and these antibodies may be correlated with the development of PAH in these patients.

Radionuclide imaging for the assessment of esophageal motility disorders in mixed connective tissue disease patients: relation to pulmonary impairment

Esophageal functional abnormalities may lead to regurgitation, chronic esophagitis and life-threatening conditions such as aspiration pneumonia. In mixed connective tissue disease patients, previous reports showed that esophageal dysfunction varies according to the method employed for investigation. Our study was conceived to: (i) assess esophageal motility and mucosal aspects in patients with mixed connective tissue disease by endoscopy, cine-esophogram and scintigraphy focusing on the prevalence of each exam; and (ii) verify the association between pulmonary and esophageal dysfunctions. Twenty-four mixed connective tissue disease patients were enrolled for this study. Cine-esophogram and upper digestive endoscopy with mucosal biopsy were performed according to previous standardization. Radionuclide esophageal scintigraphy was performed with a semisolid meal with (99m)Tc. Eleven healthy individuals voluntarily submitted to scintigraphy as controls. Cine-esophogram showed esophageal delayed emptying in 90% of patients. At scintigraphy there was a significant delay in total esophageal transit time in the group of patients when compared to healthy controls (35.3 +/- 8.2 s. vs. 13.6 +/- 9.5 s.; P < 0.0001). The whole esophageal body showed dysmotility in 96% of patients. The cine-esophogram detected functional esophageal impairment similar to scintigraphic findings. Histopathologic examination found esophagitis in 95% of studied patients. Reduced lung volumes were associated with esophagitis and delayed esophageal clearance at scintigraphy, observed at the distal portion of the esophagus. Esophageal scintigraphy is easy to perform, with good acceptance by patients with low radiation exposition. It is a useful non-invasive test for follow-up and interventional studies concerning esophagus dysfunction.

Myositis in mixed connective tissue disease: a unique syndrome characterized by immunohistopathologic elements of both polymyositis and dermatomyositis

OBJECTIVE: To characterize the inflammatory cells, the expression pattern of adhesion molecules (ICAM-1 and VCAM-1), membrane attack complex (C5b-9), and major histocompatibility complex (MHC) antigens in muscle biopsy of mixed connective tissue disease (MCTD). METHOD: We studied 14 patients with MCTD, and compared to 8 polimyositis (PM) patients, 5 dermatomyositis (DM) and 4 dystrophies. Inflammatory cells were examined for CD4+, CD8+, memory and naïve T cells, natural killer cells, and macrophages. Expression of MHC-I and -II, ICAM-1, VCAM-1 and C5b -9 were characterized on muscle fibers and vessels. RESULTS: Morphological analysis displayed a pattern of PM. Immunohistochemical study revealed a decreased number of capillaries, predominance of CD4+ and B cells in perivascular regions and predominance of CD8+ and CD45RO+ in endomysial regions. The expression of MHC-I on vessels and on degenerated muscle fibers, MHC-II expression on vessels and perifascicular muscle fibers, and the expression of ICAM-1 / VCAM-1 on endothelial cells indicated both vascular and cellular-immune mediated processes causing the muscular lesion. CONCLUSION:Our findings revealed a mixed mechanism in MCTD, both vascular involvement as DM, and cell-mediated like PM.