Hla type as a predictor of mixed connective tissue disease differentiation ten-year clinical and immunogenetic followup of 46 patients

Objective. To determine any clinical or genetic markers of differentiation and outcome in a previously described cohort of 46 patients with mixed connective tissue disease (MCTD). Methods. Patients were clinically evaluated, chart notes reviewed, and HLA subtyping and immunology profiles performed where possible. Eleven had died and 7 were lost to followup. Results. MCTD had differentiated into systemic lupus erythematosus in 12 patients and into systemic sclerosis in 13. The latter was associated with HLA-DR5 (P = 0.038), and nondifferentiation was associated with HLA-DR2 or DR4 (P = 0.007). Three HLA-DR4 positive patients had MCTD that evolved into rheumatoid arthritis. Erosive and/or deforming arthritis was associated with HLA-DR1 or DR4 (P = 0.015). HLA-DR3 was associated with interstitial lung fibrosis (P = 0.044) and keratoconjunctivitis sicca (0.001 < P < 0.01). Severe Raynaud's phenomenon predicted higher mortality (0.01 < P < 0.05). Conclusion. We suggest that MCTD is, for most patients, an intermediate stage in a genetically determined progression to a recognized connective tissue disease. Those whose disease remains undifferentiated might be considered a distinct subset.     

Sarcoidosis in patients with mixed connective tissue disease: clinical, genetic, serological and histological observations

The objective of this study was to investigate how the development of sarcoidosis influences the disease course of mixed connective tissue disease (MCTD). The cellular composition of MCTD-associated sarcoidosis granulomas was evaluated and also the disease-accompanying T-cell activation and alterations of the serum cytokine levels were measured before and after the therapy. The HLA-DR specific alleles were also assessed. We present two cases with MCTD coexisting sarcoidosis. Serum concentrations of Th1 and Th2 cytokines were assessed by ELISA. Peripheral blood CD3+ total T-cell numbers, CD4+ and CD8+ T-cell subset were determined by flow cytometry. Furthermore, hematoxylin-eosin staining and immunhistochemistry were performed for histological assessment. HLA-DR specific alleles were determined by using PCR-SSP. Elevated number of activated T-cells and high Th1 cytokine levels were detected, mainly IFN-gamma and TNF-alpha. Histologically, CD4+ and CD8+ T-cells were present in the sarcoidosis infiltrations. The haplotypes were to some extent dissimilar from the HLA-DR genotype from patients with MCTD, or sarcoidosis alone. Sarcoidosis enhances the activation of MCTD, based on the laboratory and clinical findings. Our results show that the inflammation is mainly in the effector phase, while granuloma formation is characteristic of the resolution phase of the disease. The assessment of the cytokine network in sarcoidosis-associated MCTD enables us to select the most effective, individualized therapy protocol for these patients.     

Does Mixed Connective Tissue Disease Exist? Yes

For patients who have combined features of rheumatoid arthritis, the limited cutaneous form of systemic sclerosis, and inflammatory myopathies, the concept of mixed connective tissue disease (MCTD) often helps to predict and diagnose organ problems and to educate the patient accordingly. With high titer IgG antibodies to U1 ribonucleoprotein (U1-snRNP), this concept is supported by a specific serologic marker, and autoantibodies to U1-snRNP and to heterogeneous nuclear ribonucleoprotein (hnRNP)-A2 display MCTD specificity with regard to the recognized epitopes. In addition, the association of MCTD with HLA-DR4 distinguishes it from systemic erythematosus lupus and systemic sclerosis, and speaks to its being a disease entity, rather than a mixture of yet undifferentiated collagen vascular diseases. The authors believe that the concept is useful in daily practice and accurate in the idea that MCTD constitutes a disease entity of its own.     

Cardiac abnormalities in mixed connective tissue disease

Sixteen patients with mixed connective tissue disease (MCTD) were studied using noninvasive cardiovascular techniques. Cardiovascular abnormalities including pericarditis, asymmetric septal hypertrophy, and LV dilatation were found in 38 percent of the study group. Borderline ECG and echocardiographic abnormalities were present in 31 percent of the study group, and the remaining 31 percent were normal by all study techniques. MCTD patients have a high prevalence of cardiovascular abnormalities when studied noninvasively. The most common clinical abnormality is a steroid-responsive pericarditis, present in 25 percent of our series.     

Ribosomal P protein P0 as a candidate for the target antigen of anti-endothelial cell antibodies in mixed connective tissue disease

OBJECTIVE: To evaluate the presence of anti-endothelial cell antibodies (AECA) in patients with mixed connective tissue disease (MCTD) compared to those with systemic sclerosis (SSc) and to determine the candidates for the endothelial auto-antigen that reacts with AECA in patients with MCTD using a molecular cloning strategy. METHODS: AECA were measured by a cellular enzyme-linked immunosorbent assay (ELISA) using fixed human umbilical vein endothelial cells (HUVEC) in 47 MCTD patients, 68 SSc patients, and 52 normal controls. A HUVEC cDNA expression library was immunoscreened with pooled sera from 6 patients with high AECA levels determined by cellular ELISA to explore the endothelial autoantigens in MCTD. An ELISA assay for anti-ribosomal protein P0 antibodies was used to assess the correlation with AECA levels. RESULTS: The candidate target proteins recognized by AECA in MCTD included: (i) ribosomal protein P0; (ii) a putative oncogene derived from dek mRNA; (iii) SS-B/La protein; (iv) U1 RNA-associated 70K protein; and (v) DNA-binding protein B. A significant correlation between the levels of AECA and anti-ribosomal protein P0 antibodies was demon-strated in MCTD, but not in systemic sclerosis. The sera containing high levels of AECA from patients with MCTD frequently cross-reacted with ribosomal protein P0. On the other hand, sera without AECA activity from patients with MCTD never reacted with ribosomal protein P0. CONCLUSION: AECA were more frequently seen in patients with MCTD than in patients with SSc. Ribosomal protein P0 may be one of the major target antigens of AECA in patients with MCTD.     

Clinical and immunologic manifestations of mixed connective tissue disease in a Miami population compared to a Midwestern US Caucasian population

OBJECTIVE: A cross-sectional study of mixed connective tissue disease (MCTD) was performed to determine if there were identifiable differences in the clinical expression of MCTD associated with race or ethnicity. METHODS: Miami, Florida, and Midwestern US (Missouri) Caucasian MCTD cohorts were studied. Clinical and laboratory features of the 2 MCTD cohorts were compared. A concurrently collected cohort of Sm-positive patients with systemic lupus erythematosus (SLE) was studied as a control. Disease activity and severity and functional status were measured. CD4+CD25(high)-expressing T-regulatory cells were enumerated and serum soluble L selectin was measured as biomarkers of disease activity. RESULTS: The Miami and Missouri Caucasian MCTD groups, while differing from the SLE group, were largely similar; however, gastroesophageal reflux, sclerodactyly, and malar rash were significantly more frequent in the Missouri MCTD group and alopecia was more frequent in the Miami MCTD group. Significant clinical and laboratory differences were found between the Miami MCTD and Miami SLE groups despite similar disease duration, activity, severity and functional status. Raynaud's phenomenon (RP), hand swelling, synovitis, myositis, and sclerodactyly were all significantly more common in RNP-positive MCTD versus Sm-positive SLE subjects. CONCLUSION Ethnic differences were observed in the frequency of end-organ involvement in the Miami MCTD versus the Missouri Caucasian MCTD groups. Clinical and laboratory features of all MCTD groups were clearly different from the SLE group, despite similar disease activity, disease severity, and functional status. Disease activity measures appeared to behave similarly as valid measures of disease activity in SLE and MCTD.     

Gouty Arthritis in a Female Patient with Mixed Connective Tissue Disease

Gout with systemic lupus erythematosus (SLE) or progressive systemic sclerosis (PSS) has rarely been reported, whereas mixed connective tissue disease (MCTD) with the demonstration of intra-articular monosodium urate crystals has never been reported. We describe an unusual case of MCTD (SLE–PSS) in a 37-year-old woman who developed acute gouty arthritis. Arthrocentesis and synovianalysis may be necessary to differentiate gout from the arthropathy of MCTD. Received: 15 March 1999 / Accepted: 29 July 1999     

Serum levels of tissue inhibitor of metalloproteinases in patients with mixed connective tissue disease

OBJECTIVE: To determine serum tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 levels in patients with mixed connective tissue disease (MCTD) and investigate whether these levels were correlated with the clinical or serological features of this disease. METHODS: Serum TIMP-1 and TIMP-2 levels were measured with specific enzyme-linked immunosorbent assays. Serum samples from 26 patients with MCTD and 18 healthy individuals were examined. RESULTS; Serum levels of TIMP-1 were significantly higher in patients with MCTD than those in healthy individuals (mean +/- SD: 218.9 +/- 50.8 ng/ml versus 160.0 +/- 38.7 ng/ml, P < 0.0001). MCTD patients with elevated TIMP-1 had esophageal involvement at a significantly higher incidence than those without (77.8% versus 35.3%, p < 0.05). There was no difference in serum TIMP-2 levels between patients with MCTD and healthy controls (75.6 - 11.9 ng/ml versus 77.3 +/- 10.7 ng/ml). CONCLUSION: These results suggest that TIMP-1 is involved in the pathogenesis of MCTD, and that TIMP-1 may be a serological marker for the presence of esophageal involvement in these patients.     

A possible role of anti-endothelial cell antibody in the sera of MCTD patients on pulmonary vascular damage relating to pulmonary hypertension]

OBJECTIVES: Pulmonary hypertension (PH) is one of the major fatal causes in patients with mixed connective tissue disease(MCTD), which showed remarkable angiopathy from large to small vessels in the lungs. However, the etiology of PH in MCTD is still unknown. Even the lung tissues of MCTD patients without overt clinical PH represent minor vascular damages such as microthrombus or slight intimal thickening. These findings suggest some serum factors cause endothelial cell damage especially to pulmonary micro vessels, which leads to PH in MCTD. To elucidate the mechanisms of PH in MCTD we studied the anti-endothelial cell antibodies (AECA) in the sera of MCTD patients, which are considered to correlate with activity in some collagen diseases, and compared the three kinds of endothelial cells, especially the effects on pulmonary endothelial cells. MATERIALS AND METHODS: Sera from 14 MCTD patients who satisfied the Kasukawa's criteria in Japan including 4 cases of PH, 8 cases of non-PH and 3 untreated cases, and 5 healthy controls were analyzed as follows: (1) AECA to human pulmonary arterial endothelial cells (HPAEC), pulmonary microvascular endothelial cells (HMVE-L) and human aortic endothelial cells(HAEC) were analyzed by an indirect immunofluorescence method using flow cytometry. (2) Effects of MCTD patients' and healthy controls' sera on cell proliferation and induction of apoptosis on cultured HPAEC were investigated by methods of MTS and TUNEL. (3) A cytotoxic effect of patients' sera in combination with activated NK cells on HPAEC were studied by a method of LDH concentration. RESULTS: (1) Patients' sera from MCTD have IgG type AECA, and sera from MCTD patients with PH showed a higher intensity of AECA compared with non-PH and control cases (P < 0.01). (2) Only patient's sera revealed no potency of cell proliferation and induction of apoptosis in every kinds of endothelial cells compared with controls. (3) Sera from MCTD patients with PH, and from untreatment patients were high intensity of AECA, which shows cytotoxicity by addition of activated NK cells. CONCLUSIONS: Apoptosis of pulmonary arterial endothelial cells induced by AECA in combination with activated NK cells may be the fist step of vascular damage associated with pulmonary hypertension in patients with MCTD.     

HLA-DR4 and Gm(1,3;5,21) are associated with U1-nRNP antibody positive connective tissue disease.

Patients with U1-nRNP antibodies (n = 35, 31 female, four male) were typed for HLA-A, -B, -C, and -DR antigens and IgG heavy chain allotypes G1m(1), -(2), -(3), G3m(5), and -(21). The patient group was clinically heterogeneous. Four met the American Rheumatism Association criteria for systemic lupus erythematosus, six for progressive scleroderma, and 14 for rheumatoid arthritis. Sicca syndrome was present in seven cases. Twenty three had overlapping features compatible with mixed connective tissue disease (MCTD). Healthy blood donors served as controls for HLA typing (n = 64), Gm typing (n = 228), or both (n = 56). Sixty six per cent of the patients with U1-nRNP antibodies were DR4 positive compared with 28% of the controls (relative risk = 4.9, p = 0.00053). The Gm(1,3;5,21) phenotype was found in 46% of the patients and 25% of the controls (relative risk = 2.47, p = 0.0247). Within the patient group Gm(1,3;5,21) was found only in DR4 positive individuals. The coincidence of HLA-DR4 and Gm(1,3;5,21) increases the relative risk values to 8.0 (compared with the group with neither risk factor). DR4 and Gm(1,3;5,21) primarily seem to be related to U1-nRNP antibody formation and not to disease expression. Patients with or without MCTD did not differ with respect to DR4 or Gm(1,3;5,21) frequency. Disease onset was earlier in patients with HLA-DR4/Gm(1,3;5,21) than in patients without both markers (mean 27.9 v 40.1 years; p less than 0.05).     

Evaluation of interstitial lung disease in mixed connective tissue disease (MCTD)

OBJECTIVE: Interstitial lung disease (ILD) may be a characteristic, often serious, manifestation of mixed connective tissue disease (MCTD). In this retrospective study, the frequency and clinical picture of ILD were determined in patients with MCTD using two diagnostic tests: high-resolution computed tomography (HRCT) and inhaled aerosol clearance times of (99m)Tc-labelled diethylene-triamine pentaacetate ((99m)Tc-DTPA). In addition, pulmonary function, effects of therapy and a variety of immunoserological markers were also assessed. METHODS: One hundred and forty-four consecutive patients with MCTD were selected from the clinic, irrespective of the presence or absence of ILD. All patients underwent a detailed clinical assessment, chest HRCT scanning, chest radiography, inhaled aerosol of (99m)Tc-DTPA clearance times, and all pulmonary function tests. Patients who had active ILD received corticosteroid (CS) or CS in combination with cyclophosphamide (CPH). All investigations were repeated after 6 months of immunosuppressive therapy. RESULTS: Ninety-six out of 144 MCTD patients (66.6%) had active ILD, 75 of this group (78.1%) showed ground glass opacity, 21 patients (21.8%) ground glass opacity with mild fibrosis with HRCT. Forty-five patients with active ILD received 2 mg/kg/day CS for 6-8 weeks alone and 51 patients CS in combination with CPH (2 mg/kg/day). Six months later, after therapy, 67 out of 96 MCTD patients with ILD (69.8%) showed a negative HRCT pattern, ground glass opacity with mild fibrosis developed in 15 patients (15.6%), and fibrosis was detected in 13 patients (13.5%). Only one patient showed subpleural honeycombing. (99m)Tc-DTPA was rapid in all 96 MCTD patients with active ILD (28.7 +/- 8.2 min, normal value >40 min). After therapy the (99m)Tc-DTPA was normalized, 79 out of 96 patients (82.3%). Carbon monoxide diffusion capacity (DLCO) was reduced in 33 out of 96 MCTD patients with active ILD (34.3%), while there were no significant differences in the pulmonary function tests between the active versus inactive stage of ILD or versus patients without ILD. The sera of 96 MCTD patients with active ILD contained a high level of immune complexes (ICs), and the total haemolytic complement levels (CH50/ml U) decreased. After 6 months of therapy, the IC levels decreased and CH50/ml levels normalized (MCTD patients before and after active ILD: IC optical density = 355 +/- 227 vs 206 +/- 92, P<0.001; CH50/ml, 38.0 +/- 12.6 U vs 64.3 +/- 13.0 U, P<0.001). CONCLUSIONS: HRCT is the gold standard for diagnosis of ILD. However, we used another method, (99m)Tc-DTPA, in order to compare this technique with HRCT. This latter technique has not been studied previously in MCTD. The elevated levels of IC and increased complement consumption indicated that IC-mediated alveolocapillary membrane damage and tissue injury might play a role in the pathogenesis of ILD in MCTD.     

Bronchoalveolar lavage fluid cells in mixed connective tissue disease

OBJECTIVE: Patients with mixed connective tissue disease (MCTD) exhibit clinical features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and polymyositis and dermatomyositis (PM-DM). The objective of this study was to clarify differences in BAL findings and immunophenotypes of BAL fluid (BALF) cells of patients with interstitial lung disease associated with these diseases. METHODOLOGY: We were unable to recruit a sufficient number of SLE patients with lung disease. We compared immunophenotypes of lymphocytes and alveolar macrophages (AM) in BALF of 20 MCTD patients with those of 21 SSc and 27 PM-DM patients and tested the relationships between immunophenotypes and pulmonary function in MCTD. RESULTS: MCTD patients had a significantly higher CD4/CD8 ratio with more CD4 positive lymphocytes than PM-DM patients (P = 0.025). In AM phenotypes, MCTD patients had a significantly lower percentage of CD71 positive AM compared with SSc patients (P = 0.023). DLCO was negatively related to absolute numbers of CD8 positive lymphocytes (R = -0.517, P= 0.033). CONCLUSIONS: CD4 positive lymphocytes in BALF were increased in MCTD compared to PM-DM patients, while CD71 positive AM were decreased in MCTD compared to SSc patients. CD8 positive lymphocytes correlated negatively with DLCO measurements in MCTD patients.     

Evaluation of paraoxonase activity in patients with mixed connective tissue disease

OBJECTIVE: Mixed connective tissue disease (MCTD) is a systemic inflammatory autoimmune disease. The connection between inflammatory measures and atherosclerosis in MCTD has not been described. Paraoxonase (PON) is known to have an antioxidant function. We evaluated lipid profiles and PON activity in patients with MCTD. METHODS: Thirty-seven patients with MCTD were enrolled. Patients had taken no antihyperlipidemic drugs in the past 2 months. Thirty healthy individuals served as controls. The mean age of patients was 51.2 +/- 9.5 years; disease duration was 11.0 +/- 7.2 years. PON activity was determined with spectrophotometry, von Willebrand factor (vWF) antigen was investigated with the immunoturbidimetry method, and thrombomodulin and antiendothelial cell antibody (AECA) measurements were carried out by ELISA. RESULTS: PON activity in patients with MCTD was significantly lower than in the controls (patients 118.5 +/- 64.6 U/l, controls 188.0 +/- 77.6; p < 0.001). Arylesterase activity was significantly reduced in patients (p < 0.001). Reduction of PON activity showed a close correlation with the age of the patients, duration of the disease, and vascular events (eye, cardiac, cerebral). There was a close association between the low PON activity and endothelial cell activation markers (thrombomodulin, vWF, AECA). CONCLUSION: Our results indicate that in patients with MCTD there is an increased risk for atherosclerosis. In the development of atherosclerosis, besides the elevated levels of cholesterol and triglyceride, reduced PON concentrations and PON activity may play a crucial role.     

Decreased capillary density in juvenile dermatomyositis and in mixed connective tissue disease.

OBJECTIVE: To assess whether quantitative capillary microscopy is a useful tool to evaluate capillary abnormalities in children with connective tissue diseases. METHODS: Eight children with juvenile dermatomyositis (JDM), 6 with mixed connective tissue disease (MCTD) and 23 healthy children were investigated with computer based quantitative capillary microscopy. Median disease duration was 1 year among JDM (1-4) and 3 years (1-7) among MCTD. RESULTS: Capillary density was decreased in JDM [median 2.5 (1.4-4.3) loops/mm (p < 0.001)] and in MCTD [median 5.0 (4.1-7.0) loops/mm (p < 0.05)] compared to healthy controls [median 6.8 (5.3-8.0) loops/mm]. Median capillary loop area was increased in JDM [median 8.5 (3.0-15.8) 10(-3) mm2 (p < 0.001)] and in MCTD [median 4.5 (3.0-6.0) 10(-3) mm2 (p < 0.02)] compared to controls [median 2.5 (1.0-4.0) 10(-3) mm2]. CONCLUSION: Quantitative nailfold capillary microscopy is a sensitive indicator of JDM. In MCTD this technique is less discriminative.     

Sicca symptoms and anti-SSA/Ro antibodies are common in mixed connective tissue disease

OBJECTIVE: To examine a large well characterized cohort of patients with mixed connective tissue disease (MCTD) and determine longitudinally the prevalence of clinical and serologic features of Sjogren's syndrome in these patients. METHODS: Patients were followed longitudinally up to 30 years with systematic clinical and serologic analysis. Sera were analyzed for reactivity with SSA/Ro, SSB/La, and snRNP polypeptide U1-70kD and for anticardiolipin antibodies. RESULTS: Among a well characterized patient population with MCTD, 18/55 (32.7%) had antibodies to SSA/Ro, while 2/55 (3.6%) had antibodies to SSB/La, either initially or during the course of followup. All patients had antibodies to U1-70kD small nuclear ribonucleoprotein antigen. Sicca symptoms were common, occurring in 23/55 (41.8%) patients. Patients with MCTD who were anti-SSA/Ro positive had increased incidence of malar rash (p < 0.03) and photosensitivity (p < 0.001) compared to anti-SSA/Ro negative patients. CONCLUSION: Sicca symptoms are frequent in patients with MCTD, occurring in up to one-third of the patients studied. The presence of anti-SSA/Ro antibodies identifies a group of MCTD patients with a very high incidence of malar rash and photosensitivity.     

Elevated circulating soluble CD40 ligand in patients with mixed connective tissue disease

 Abnormalities of CD40 ligand have been demonstrated in various kinds of diseases. Our objective was to determine serum soluble CD40 ligand (sCD40L) levels in patients with mixed connective tissue disease (MCTD). Serum sCD40L levels of 23 patients with MCTD and 21 healthy individuals were measured with specific enzyme-linked immunosorbent assays. Serum levels of sCD40L were significantly higher in patients with MCTD than in healthy individuals (median 0.179 ng/ml vs 0.99 ng/ml, 25th–75th percentile; 0.117–0.296 ng/ml vs 0.82–1.70 ng/ml, P<0.005), whereas there were no significant correlation between elevated serum sCD40L levels and clinical or serological features in patients with MCTD. These results suggest that sCD40L plays a role in the pathogenesis of MCTD. Further studies are needed to clarify this. Received: 29 March 2002 / Accepted: 28 August 2002     

Anti-endothelial cell antibodies in mixed connective tissue disease: frequency and association with clinical symptoms

OBJECTIVE: Anti-endothelial cell antibodies (AECA) have been described in a number of systemic autoimmune-inflammatory diseases. However, little is known about the relationship of AECA with mixed connective tissue disease (MCTD). METHODS: Using an ELISA, the presence of AECA was evaluated in the sera of 33 patients with MCTD and of 30 healthy subjects as controls. Serum levels of AECA were correlated with clinical activity, as well as the existence of various organ manifestations. RESULTS: Significantly increased AECA production was observed in MCTD patients (OD = 0.337+/-0.193) compared to controls (OD = 0.136+/-0.065). In addition, patients with active MCTD exerted significantly elevated serum AECA levels (OD = 0.487+/-0.090) than did patients with inactive MCTD (OD = 0.135+/-0.040) or controls. MCTD patients with pulmonary hypertension had a tendency of increased serum AECA levels (OD = 0.452+/-0.080) compared to patients without this manifestation (OD = 0.307+/-0.039). Sera of MCTD patients with AECA concentrations higher or lower than the mean serum AECA level in controls+2SD (OD = 0.266) were considered as AECAhigh (n = 19/33) and AECAlow (n = 14/33), respectively. Interestingly, all patients with active disease had AECAhigh, while all inactive MCTD patients had AECAlow sera. IgG purified from ten MCTD sera (OD = 0.415+/-0.290) showed a tendency to up-regulate E-selectin expression on cultured human umbilical vein endothelial cells (HUVEC) compared to IgG from control sera. In addition, AECAhigh MCTD sera exerted significantly increased stimulatory effect on endothelial E-selectin expression (OD = 0.651+/-0.190) compared to AECAlow (OD = 0.178+/-0.110) or control sera (OD = 0. 131+/-0.080). CONCLUSION: AECA may activate endothelial cells by the up-regulation of E-selectin expression and thus may be implicated in the pathogenesis of MCTD. Furthermore, serum AECA may be a useful marker of endothelial activation and clinical activity in this disease.     

Diastolic function of the heart in mixed connective tissue disease

The authors examined the right and left ventricle functions in patients with mixed connective tissue disease (MCTD) by Doppler echocardiography. Of 51 patients, 20 had temporary pulmonary arterial hypertension in their case history. According to our knowledge, this is the first study examining the use of Doppler echocardiography and tissue Doppler technique in MCTD patients. Of 51 MCTD patients, 20 had pulmonary arterial hypertension (PAH) in the past 2 years. Diameters of the right and left ventricle, systolic and diastolic blood pressure were measured both in the 51 MCTD patients and in the 30 control subjects (mean age 54.8±6.2 years in the case of patients and 54.2±8.8 years in the case of control subjects). To estimate the global ventricle functions, the myocardial performance index—as described by Tei et al. (J Am Soc Echocardiogr 6:838–874, 1996)—was applied, which reflects the ratio of the sum of the isovolumetric contraction and relaxation time as compared to the ejection time. The 20 MCTD patients with PAH received cyclophosphamide therapy for 1 year beside the pulse corticosteroid (CS) therapy. In the case of MCTD patients without PAH, different treatments were used: 12 out of 31 patients were treated with sulfasalazine, 5 of whom received a combination of CS and methotrexate, and 14 took nonsteroid antiinflammatory drugs. In the case of the 51 MCTD patients (20 with PAH and 31 without PAH), diastolic function disorder of the left ventricle was detected; the diastolic E _e/A _a velocity quotient of the lateral mitral anulus was lower (p<0.01), and the mean deceleration time was longer (p<0.001) than that of the control group. The Tei index demonstrated the damage of the global ventricle function. The Tei index of the right ventricle indicated global failure of the right ventricle function in the case of MCTD patients complicated with PAH (Tei index 0.36±0.07 in MCTD with PAH and 0.28±0.04 in MCTD without PAH, p<0.001). The right ventricle function of MCTD patients without PAH was no different from that of the control group. In the case of patients with MCTD, signs of the disorder of the left ventricle diastolic function were observed. Our results suggest that the global impairment of the left ventricle function is the consequence of the disease itself and not the side effect of the treatment. In the case of MCTD patients complicated with PAH, the signs of the right ventricle function impairment proved to be permanent.     

Serum cytokine levels and type 1 and type 2 intracellular T cell cytokine profiles in mixed connective tissue disease

OBJECTIVE: To determine serum cytokine concentrations and intracellular cytokine production of CD4+ and CD8+ T cells in 20 patients with mixed connective tissue disease (MCTD). METHODS: Detailed analysis of cytokine production; 8 patients were in the active stage, 12 in the inactive stage of the disease. Serum concentrations of interferon-gamma (IFN-gamma), interleukin 4 (IL-4), and IL-10 were assessed by ELISA. Intracellular content of IFN-gamma, IL-4, and IL-10 in CD4+ and CD8+ peripheral blood T cell and lymphocyte subsets was determined by flow cytometry. RESULTS: Serum concentrations of both type 1 and type 2 cytokines were significantly higher in patients with MCTD than in healthy controls. IFN-gamma expression of CD4+ and CD8+ T cells did not differ comparing all patients to controls. In patients with active MCTD, the percentage of CD8+/IFN-gamma+ Tc1 cells was significantly increased compared to inactive disease or to controls (p < 0.05). IL-4 expression of CD4+ T cells was scarcely detectable in MCTD, while a subpopulation of CD8+ Tc2 cells produced IL-4. A higher percentage of these CD8+/IL-4+ Tc2 cells were detected in patients with MCTD, especially in active disease, compared to controls (p < 0.05). The percentage of IL-10-expressing CD4+ and CD8+ T cells was higher in patients than in controls (p < 0.05). Again, CD4+ and CD8+ T cells from patients with active MCTD produced significantly more IL-10 than cells in patients with inactive disease or in controls (p < 0.05). CONCLUSION: Our results suggest that MCTD is associated with increased production of both type 1 (IFN-gamma) and type 2 cytokines (IL-4, IL-10). Cytokine production is usually higher in active MCTD than in inactive disease. CD8+ T cells may produce more IFN-gamma and IL-10 in comparison to CD4+ T cells. Patients with active disease have more IL-4-expressing Tc2 cells and IL-10-expressing Th2 and Tc2 cells than patients with inactive MCTD or controls. In MCTD, increased IL-10 production by Th2 and Tc2 cells may be an attempt by the immune system to downregulate the inflammatory reaction, although this effect may not be sufficient to restore the physiological Th1/Th2 balance in MCTD.     

PREDOMINANCE OF IgM ANTI-U1RNP ANTIBODIES IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Anti-UIRNP antibodies occur in patients with mixed connectivetissue disease (MCTD), systemic sclerosis (SSc), systemic lupuserythematosus (SLE) and other ill-defined connective tissuediseases. To associate the isotypes of anti-UlRNP antibodieswith the diagnosis of the disease, namely SLE or MCTD, sequentialsera of patients positive for anti-UlRNP antibodies by counterimmunoelectrophorcsis(CIE) (32 with SLE, 35 with MCTD) were tested for IgG and IgManti-UlRNP antibodies by enzyme-linked immunosorbent assay (ELISA)using affinity-purified UlsnRNP complexes. Results from ELISAwere confirmed by RNA precipitation. IgG RNA precipitation ofHeLa cellular extracts was performed using the bulk of the IgGfraction removed from each serum after binding to protein A-Sepharosebeads. IgM RNA precipitation was carried out on the IgM fractionof the serum bound to protein A-Scpharose-rabbit anti-humanIgM immune complexes. RNAs were electrophoresed in 10.5% acrylamide-7m urea gels and detected with the silver stain. ELISA showedthat all sera were positive to IgG anti-UlRNP, while 12 of the35 MCTD and 21 of the 32 SLE patients possessed IgM anti-UlRNP(P<0.025). IgM anti-UlRNP reactivity was found during thefollow-up in 20% of 44 sera from 17 MCTD patients and 68% of112 sera from 23 SLE patients (P<0.0001). IgG from all thesera precipitated UlRNPs. Eight of the MCTD sera also precipitatedU2RNPs and 14 of the SLE sera U2 and/or U4/U6, U5 RNPs. IgMfrom MCTD sera did not precipitate URNPs, while IgM from SLEsera precipitated predominantly UlRNPs. These data suggest thatIgM anti-UlRNP antibodies occur predominantly in patients withSLE. The occurrence of IgG anti-UlRNP without IgM is more frequentin MCTD. KEY WORDS: Anti-UIRNP, Anti-Sm, Autoanubodies, Isotypes, SLE, MCTD