Rheumatoid arthritis and small airways function. Effects of disease activity, smoking, and alpha 1-antitrypsin deficiency

Contrasting diagnosis performance of forced oscillation and spirometry in patients with rheumatoid arthritis and respiratory symptoms

OBJECTIVES

Pulmonary involvement in rheumatoid arthritis is directly responsible for 10% to 20% of all mortality. The best way to improve the prognosis is early detection and treatment. The forced oscillation technique is easy to perform and offers a detailed exam, which may be helpful in the early detection of respiratory changes. This study was undertaken to (1) evaluate the clinical potential of the forced oscillation technique in the detection of early respiratory alterations in rheumatoid arthritis patients with respiratory complaints and (2) to compare the sensitivity of forced oscillation technique and spirometric parameters.

METHODS

A total of 40 individuals were analyzed: 20 healthy and 20 with rheumatoid arthritis (90% with respiratory complaints). The clinical usefulness of the parameters was evaluated by investigating the sensibility, the specificity and the area under the receiver operating characteristic curve. ClinicalTrials.gov: NCT01641705.

RESULTS

The early adverse respiratory effects of rheumatoid arthritis were adequately detected by the forced oscillation technique parameters, and a high accuracy for clinical use was obtained (AUC.0.9, Se = 80%, Sp = 95%). The use of spirometric parameters did not obtain an appropriate accuracy for clinical use. The diagnostic performance of the forced oscillation technique parameters was significantly higher than that of spirometry.

CONCLUSIONS

The results of the present study provide substantial evidence that the forced oscillation technique can contribute to the easy identification of initial respiratory abnormalities in rheumatoid arthritis patients that are not detectable by spirometric exams. Therefore, we believe that the forced oscillation technique can be used as a complementary exam that may help to improve the treatment of breathing disorders in rheumatoid arthritis patients.

Pulmonary manifestations of rheumatoid arthritis

Pulmonary disease is a major source of morbidity and mortality in rheumatoid arthritis, manifesting most commonly as interstitial lung disease, airways disease, rheumatoid nodules, and pleural effusions. The diagnostic assessment of respiratory abnormalities is complicated by underlying risk for infection, the use of drugs with known pulmonary toxicity, and the frequency of lung disease related to rheumatoid arthritis itself. Evaluation and management of rheumatoid arthritis-associated pulmonary disease frequently necessitates a multidisciplinary approach.

Small airway obstruction in patients with rheumatoid arthritis

This work was intended to evaluate the prevalence of obstructive small-airway disease in patients with rheumatoid arthritis (RA) and its association with clinical characteristics. Pulmonary function testing (PFT) and high-resolution computed tomography (HRCT) were performed on 189 consecutive RA patients. Each case was diagnosed based on abnormal HRCT findings. We defined obstructive dysfunction of small airways as a forced expiratory flow from 25% to 75% of vital capacity (FEF(25-75)) value >1.96 residual standard deviation (RSD) below predicted values. We found 19 patients (10.1%) with an interstitial pneumonia (IP) pattern and 15 (7.9%) with a bronchiolitis pattern; the other 155 (82.0%) had no abnormal HRCT patterns. In patients with neither abnormal pattern, median values of percentage predicted for carbon monoxide diffusing capacity (DL(CO)) and ratio of DL(CO) to alveolar ventilation (DLco/VA) were within the normal range, but median FEF(25-75), forced expiratory flow at 25% of vital capacity (V(25)), and V(25)/height were <70% of predicted values. Forty-seven patients (30.3%) in this group had obstructive small-airway dysfunction. Multivariate logistic regression analysis indicated that this type of abnormality is strongly associated with respiratory symptoms [odds ratio (OR) 5.18; 95% confidence interval (CI) 1.70-15.75; p = 0.012), smoking history (OR 2.78; 95% CI 1.10-6.99; p = 0.03), and disease duration >10 years (OR 2.86; 95% CI 1.27-6.48; p = 0.012). Parenchymal micronodules, bronchial-wall thickening, and bronchial dilatation on HRCT scans were also predictive factors for abnormal FEF(25-75), although these morphological changes were too limited for us to diagnose these patients with the bronchiolitis pattern. Obstructive dysfunction of small airways is apparently common among RA patients, even among those with neither the IP nor the bronchiolitis pattern on HRCT scans. Factors significantly associated with abnormal FEF(25-75) are respiratory symptoms, smoking history, and RA duration.

Pulmonary manifestations of rheumatoid arthritis

Rheumatoid arthritis (RA) is the most common of the classic connective tissue diseases. Its manifestations in the chest are varied as the pleura, lung parenchyma, airways, and pulmonary vasculature can all be involved. The approach to a patient with RA and respiratory complaints, radiographic findings, or physiologic abnormalities requires a broad understanding of these manifestations. Moreover, the potential for therapy-related toxicity adds further complexity to the pulmonary evaluation of these patients.

Airways involvement in rheumatoid arthritis: clinical, functional, and HRCT findings

The aim of the present study was to assess the prevalence and characteristics of airways involvement in rheumatoid arthritis (RA) patients in the absence of interstitial lung disease. We prospectively evaluated, with high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs), 50 patients with RA (nine males and 41 females; mean age: 57.8 yr), including 39 nonsmokers and 11 smokers (mean cigarette consumption: 15.3 pack-yr) without radiographic evidence of RA-related lung changes. PFTs demonstrated airway obstruction (i.e., reduced FEV1/VC) in nine patients (18%) and small airways disease (SAD) (i.e., decreased FEF(25-75), defined as exceeding the predicted value by 1.64 residual SD [RSD] or more, and/or an increased phase III slope > 2 SD by single breath nitrogen washout) in four patients (8%). HRCT demonstrated bronchial and/or lung abnormalities in 35 cases (70%), consisting of air trapping (n = 16; 32%), cylindral bronchiectasis (n = 15; 30%), mild heterogeneity in lung attenuation (n = 10; 20%), and/or centrilobular areas of high attenuation (n = 3; 6%). Airway obstruction and SAD were correlated with the presence of bronchiectasis and bronchial-wall thickening (p = 0.003), and with bronchial infection (p = 0.01), but were unrelated to rheumatologic data. FEF(25-75) was reduced and the slope of phase III was increased in patients with airway changes on HRCT scans, whereas no PFT abnormalities were found in 13 of 15 patients with normal HRCT scans. HRCT depicted features of SAD in 20 of the 33 patients with normal PFTs. HRCT findings were unrelated to rheumatologic data. A high prevalence of airway abnormalities as assessed with HRCT and/or PFTs was observed in our RA population. HRCT appears to be more sensitive than PFTs for detecting small airways disease.

[Bronchiectasis and rheumatoid arthritis. Incidence and etiopathogenic aspects. Review of the literature]

Many pleural and pulmonary manifestations are described in rheumatoid arthritis, due to the disease itself or drug-induced. A literature review revealed 289 reports of bronchiectasis since 1928, the respiratory symptoms preceding the articular features in 90%. Although the frequency of bronchiectasis in the general population is difficult to assess, and thus maybe underestimated, the prevalence in rheumatoid arthritis seems higher. Thus the recent studies, using modern processes such as high resolution computed tomography of the lungs, assess this association to about 25%. Nevertheless, the methodology of these studies is open to criticism, so the high frequency must be qualified. The pathogenic and aetiological factors remain unknown, and miscellaneous hypotheses, especially immunological, have been suggested. The relationship between both affections can not be asserted, but the association is unlikely to be fortuitous.

High resolution computed tomography of the lung in lifelong non-smoking patients with rheumatoid arthritis

OBJECTIVES

To define pulmonary involvement on high resolution computed tomography (HRCT) of the thorax in lifelong non-smoking rheumatoid arthritis patients and to relate the results to pulmonary function, bronchial reactivity, and a variety of clinical and serological factors.

METHODS

Twenty lifelong non-smoking RA patients (mean age 59 years (range 44-72; 18 females) were studied. Detailed medical and drug histories were taken. Protease inhibitor phenotype (Pi) and HLA-DR4 status were assessed. Schirmer's tear tests were performed to detect keratoconjunctivitis sicca (KCS). Spirometry, flow volume loops, and gas transfer factor measurement were recorded. The degree of bronchial reactivity (PC20 FEV1) was measured by a methacholine inhalation test. Chest and hand radiographs and HRCT of the lung were performed in all patients.

RESULTS

Thirteen patients were HLA-DR4 positive. Eighteen had the Pi MM and two the Pi MS phenotype. Eight patients had evidence of KCS on Schirmer's tear testing. Ten patients achieved PC20 FEV1 in the methacholine inhalation test. All the patients had normal chest radiographs and all showed evidence of erosive arthropathy on hand radiographs. Five patients (25%) showed basal bronchiectasis and one mild interstitial lung disease on HRCT. All five patients with bronchiectasis had the Pi MM phenotype, four had HLA-DR4, four had KCS and three achieved PC20 FEV1; these values were not significantly different (p > 0.05) from those in patients without bronchiectasis.

CONCLUSION

Using the highly sensitive technique of HRCT, we found evidence to suggest that the incidence of bronchiectasis in lifelong non-smoking RA patients may be much higher than previously reported.

An 8-year follow-up study of pulmonary function in patients with rheumatoid arthritis

To evaluate longitudinal alterations in pulmonary function, 63 patients suffering from rheumatoid arthritis (RA) with previously reported reduced pulmonary diffusing capacity were re-examined in an 8-year follow-up study. Cross-sectional examination revealed normal values for vital capacity (VC), forced expiratory volume in 1 s (FEV1) and diffusing capacity per litre alveolar volume (KCO). Total diffusing capacity (DLCO; P < 0.0001), maximal expiratory flow at 75% of expired VC (MEF75; P < 0.0001) and MEF50 (P < 0.01) were decreased. Longitudinal evaluation revealed unchanged MEF50, MEF75 and FEV1, whereas increases in DLCO (P < 0.0001) and KCO (P < 0.0001) and a decrease in VC (P < 0.05) were found. The longitudinal changes in diffusing capacity were unrelated to patient age, disease duration, disease activity in the study period or pulmonary function at the first examination. Thus, in patients suffering from RA, the most prominent functional pulmonary abnormality, decreased diffusing capacity, appeared to improve in the course of time, despite a slight decrease in VC and continued articular disease activity.

Bronchial reactivity and airflow obstruction in rheumatoid arthritis

OBJECTIVES

To investigate the prevalence of airways obstruction and bronchial reactivity to inhaled methacholine in rheumatoid arthritis patients and unselected controls. The control population consisted of patients attending the rheumatology department for minor degenerative joint problems.

METHODS

One hundred patients with rheumatoid arthritis (RA) [72 (72%) women, 28 (28%) men; mean (SD) age 58 (10) years] and fifty controls [30 (60%) women, 20 (40%) men; mean (SD) age 56 (9) years] were studied. Detailed medical, smoking and drug histories were taken; skin prick tests were performed to assess atopy and chest and hand radiographs were performed. Spirometry, flow volume loops and gas transfer factor measurement were performed to detect airflow obstruction and methacholine inhalation tests were carried out to assess bronchial reactivity.

RESULTS

There was no significant difference between rheumatoid arthritis patients and the controls in age, sex, smoking status and atopy on skin prick testing (p < 0.05). A significantly higher number of patients with RA had a history of wheeze compared with the controls (18% v 4%, p < 0.05). FEV1, FVC, FEV1/FVC, FEF25-75%, FEF25%, FEF50% and FEF75% were all significantly lower in the rheumatoid arthritis group (p < 0.05). A significantly higher number of patients with RA compared with controls showed bronchial reactivity to inhaled methacholine [55 (55%) v 8 (16%), p < 0.05]. FEV1, FVC, FEV1/FVC, FEF25-75%, FEF25%, FEF50% and FEF75% were all significantly lower among the patients with RA achieving PD20 FEV1 to inhaled methacholine (p < 0.05).

CONCLUSION

In unselected rheumatoid arthritis patients both airflow obstruction and bronchial reactivity are significantly increased compared with controls.

Pericardial and pulmonary involvement in rheumatoid arthritis in Turkey

Pericardial and lung involvement in rheumatoid arthritis (RA), suspected to be less severe in a developing nation (Turkey), have been evaluated. We have studied clinical, echocardiographic and pulmonary findings (radiological and functional) in 93 consecutive Turkish patients with definite/classical RA. Findings were compared with those of a group of patients with osteoarthritis or local rheumatological conditions (n = 60) in a blind protocol. Fifty patients with systemic lupus (SLE) were studied as a high risk control group for pericardial involvement. While pericardial disease was detected in 5.5% (5/90) of RA patients, it was detected in 6.6% (4/60) of the control patients. SLE patients had a 26% (13/50) prevalence. Interstitial lung disease was found in 27.7% of RA patients but it was present in 6.6% (4/60) of the control patients. We observed that a group of patients with RA in Turkey had a low prevalence of pericardial disease. This is further evidence that RA has a mild course in developing countries.

Rheumatoid arthritis: other rheumatoid lung problems

In summary, it appears that factors such as smoking and the presence of secondary Sjögren's syndrome might be important in predisposing the rheumatoid patient to the development of lung disease. Genetic factors may moderate or magnify these risks. At a cellular level, specific macrophage colonies within the lung may interact with a subgroup of CD4 T lymphocytes to produce unopposed B-cell activation, leading to local IgM production and the formation of immune complexes. This can damage lung both directly by cytolysis and indirectly by granulocyte recruitment through the release of neutrophil chemotaxins. Early in the evolution of these processes, steroids appear able to reduce lymphocyte numbers and prevent lung damage occurring, presumably by immunological mechanisms, while later they may reduce granulocyte numbers and activity, halting further progression of lung disease in some patients, perhaps by a direct anti-inflammatory effect. Confirmation of these mechanisms and the development of more specific therapeutic tools is probably dependent on studies which examine lung tissue directly by biopsy and may be aided by the application of more sensitive imaging techniques.

Smoking, lung function, and rheumatoid factors

Positive rheumatoid factor (RF) reactions commonly precede the onset of clinically manifest rheumatoid arthritis (RA). Thus if items associated with RF reactions were traced at the community level this might provide clues to the cause of RA. The relations between smoking and lung functions and the occurrence of RA and RFs in a population sample representative of the adult Finnish population were studied. Rheumatoid factor testing was performed for 7124 subjects (89% of the sample) by the sensitised sheep cell agglutination test. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were measured with spirometry. 'False positive' RF reactions occurred twice as often in current smokers and ex-smokers than in those who had never smoked. The prevalence of high titres was fourfold greater among current smokers than among those who had never smoked. These associations were statistically significant and independent of age, FVC, and FEV1 in both sexes. The women with airflow limitation (FEV1/FVC less than 70%) had a significantly increased occurrence of RFs which was independent of their smoking history, but no such relationship was found in men. The results suggest an impact of smoking on RF production; a follow up study may show whether the raised RF titers in smokers will be reflected as an increased incidence of RA.

HLA-DQw alloantigens and pulmonary dysfunction in rheumatoid arthritis

HLA-DR4 and keratoconjunctivitis sicca (secondary Sjögren's syndrome) are associated with abnormal pulmonary function in patients with rheumatoid arthritis. Since recent investigations have found that much of the genomic polymorphism of the HLA-DR4 haplotype comes from the closely linked DQw allele, we reanalyzed this set of data to evaluate the relationship between the DQw allotypes and pulmonary function in rheumatoid arthritis. Using a step-wise regression analysis, we found that the presence of DQw1 was a stronger predictor of an abnormal forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and carbon monoxide diffusing capacity (D) than the presence of DR4, keratoconjunctivitis sicca, smoking status, or any other clinical parameter. DQw1-positive patients had a mean (+/- SD) percent of predicted FEV1, FVC, and D of 84.2 (+/- 19.8), 88.0 (+/- 17.9) and 85.6 (+/- 20.9) percent, respectively, all significantly lower than DQw-1 negative patients (p = 0.02, 0.02, and 0.03). Smokers with the heterozygous phenotype, DQw1/DQw3, tended to have obstructive disease of the airways, with a mean (+/- SD) FEV1 of 80.1 +/- 24.4 percent of predicted, compared to 95.7 +/- 12.1 percent of predicted in DQw1/DQw3-negative individuals (p = 0.03). Patients who had a DQw2 allele were more likely to have normal pulmonary function. We conclude that the HLA-DQw1 allotype is a strong predictor of abnormal pulmonary function and that it may identify smoking subjects with rheumatoid arthritis subjects who are prone to develop obstruction of airflow.

HLA-DR4 and pulmonary dysfunction in rheumatoid arthritis

Rheumatoid arthritis is associated with an increased frequency of the B cell alloantigen HLA-DR4, and preliminary work has suggested an association between HLA-DR4 and obstructive lung disease in subjects with rheumatoid arthritis. To prospectively evaluate the influence of HLA-DR4 on pulmonary involvement in patients with rheumatoid arthritis, pulmonary function was measured in four groups of subjects with rheumatoid arthritis in whom HLA-DR4 and smoking status was known: 16 DR4-positive smokers (six current and 10 exsmokers), 16 DR4-negative smokers (six current and 10 exsmokers), eight DR4-positive nonsmokers, and eight DR4-negative nonsmokers. Significant reductions in one-second forced expiratory volume and forced vital capacity were observed in DR4-positive subjects compared with DR4-negative subjects irrespective of cigarette smoking status. In addition, patients with keratoconjunctivitis sicca (secondary Sjögren's syndrome) demonstrated significant reductions in one-second forced expiratory volume, forced vital capacity, and ratio of one-second forced expiratory volume to forced vital capacity compared with those patients without evidence of secondary Sjögren's syndrome. It is concluded that the presence of the HLA-DR4 antigen and secondary Sjögren's syndrome are associated with abnormal pulmonary function in patients with rheumatoid arthritis.

Airways disease in rheumatoid arthritis patients. One element of a general exocrine dysfunction

Airflow limitation is a frequent finding in patients with rheumatic diseases. We have previously suggested that it is associated with autoimmune exocrinopathy in Sjögren's syndrome. To compare clinical features of patients with and without airways dysfunction and to further test the hypothesis of a link between airways disease and exocrinopathy, we prospectively studied 2 groups of 15 lifetime nonsmoker female patients with seropositive rheumatoid arthritis (RA). The 2 groups were similar in their clinical and immunologic features, but differed in terms of airways function. Salivary, lacrimal, and sweat gland dysfunction were significantly more prevalent or severe in the group with airways disease. Antinuclear antibodies were also more prominent in the patients with airways disease, but antibodies against RNP, SS-A, SS-B, and double-stranded DNA were not present in these patients. HLA-DR4 was found in 80% of the RA patients with airways disease and in 57% of those without airways disease. HLA-B8 and DR3 were equivalently distributed in both groups. This prospective study further documents the existence of small airways disease in RA and supports the view that autoimmune exocrinopathy predisposes to its expression.

Association of bronchiolitis with connective tissue disorders

Among 173 consecutive open lung biopsies, nine gave a histopathological diagnosis of bronchiolitis. Seven of these patients had some connective tissue disorder (CTD), six of whom are presented in this report; two had classical and one possible rheumatoid arthritis (RA), one ankylosing spondylitis, one scleroderma, and one developed classical RA four years after biopsy. Four of the patients were smokers, most suffered from breathlessness and cough. In terms of lung function three patients had obstruction, one both restriction and obstruction and three a decreased diffusion capacity. For control purposes peripheral lung tissue was studied histologically from 24 consecutive smoking patients without CTD who underwent a lobectomy for cancer. Intraluminal plugs and mucosal lymphoplasmocytic infiltration of the bronchiolar walls were more prevalent and abundant in the CTD patients than in the controls (p less than 0.02 and p less than 0.001 respectively). Two CTD patients also showed some obliterative bronchiolitis. Corticosteroids were effective in one out of four patients treated. One patient improved and the others did not show any progression during the follow up. The results suggest that smoking alone does not explain the lesions of the small airways found in CTD patients, and that bronchiolitis may be specifically associated with the basic disorder in such cases.

Lung function abnormalities in different connective tissue diseases

Lung volumes, forced expiratory flow-volume curves, diffusing capacity indexes, and arterial blood gases were measured in 72 non-smoking patients with various connective tissue diseases (13 with rheumatoid arthritis, 17 with systemic lupus erythematosus, 25 with progressive systemic sclerosis, 10 with primary Sjögren's syndrome, 4 with polymyositis, and 3 with mixed connective tissue disease). Small airways disease and a diffusion capacity impairment were the most frequent and marked functional abnormalities in the whole group, and were often present in asymptomatic patients. Different lung function defects seemed to be present in each disease group. In fact, large airway obstruction was prevalent in progressive systemic sclerosis, diffusion capacity impairment in systemic lupus erythematosus, and small airways disease in rheumatoid arthritis. In contrast, primary Sjögren's syndrome appeared to be the connective tissue disease in which lung function abnormalities were less frequent and less pronounced.

Alpha 1-antitrypsin phenotypes, including M subtypes, in pulmonary disease associated with rheumatoid arthritis and systemic sclerosis

Alpha 1-antitrypsin is a glycoprotein that functions as the major protease inhibitor in human serum. Many genetic variants of alpha 1-antitrypsin can be detected by electrophoretic techniques. We used isoelectric focusing on ultrathin gels to determine the common M subtypes as well as other variants of alpha 1-antitrypsin in 62 white patients with rheumatoid arthritis (RA) and 51 white patients with systemic sclerosis (SSc). We found no increased prevalence of variant phenotypes in either disease group as a whole. In RA, however, the association between pulmonary interstitial fibrosis and alpha 1-antitrypsin variants was striking. Interstitial fibrosis was seen on chest roentgenogram in only 1 of 30 subjects apparently homozygous for M1 (the "wild type" or "normal" phenotype), compared with 13 of 32 patients with variant phenotypes. Seven of 15 patients with M1M2 (the most common variant phenotype) had pulmonary fibrosis. In contrast, there was no apparent association of variant phenotypes with pulmonary involvement in SSc. Our findings suggest a possible role of alpha 1-antitrypsin in the pathogenesis of interstitial fibrosis in patients with RA. The absence of such an association in SSc suggests that pulmonary involvement in these 2 rheumatic diseases may have different pathogeneses.

Rheumatoid arthritis: clinical features and pathogenetic mechanisms

Rheumatoid arthritis is a disorder characterized by chronic inflammation affecting predominantly articular tissues, leading in some instances to disruption of the normal structure and function of the joint. In some patients extra-articular manifestations are also present. In the joints, the pathologic lesion consists of synovial cell proliferation with infiltration by inflammatory cells. The complex interaction among these cells is likely responsible for the connective tissue abnormalities that characterize the rheumatoid lesion. The factors responsible for inducing the inflammatory process are unknown.