[Analysis of referral diagnoses to the rheumatology department]

Diagnosing lung involvement in inflammatory rheumatic diseases-Where do we currently stand?

Lung involvement is the most common and serious organ manifestation in patients with inflammatory rheumatic disease (IRD). The type of pulmonary involvement can differ, but the most frequent is interstitial lung disease (ILD). The clinical manifestations of IRD-ILD and severity can vary from subclinical abnormality to dyspnea, respiratory failure, and death. Consequently, early detection is of significant importance. Pulmonary function test (PFT) including diffusing capacity of the lungs for carbon monoxide (DLCO), and forced vital capacity (FVC) as well as high-resolution computed tomography (HRCT) are the standard tools for screening and monitoring of ILD in IRD-patients. Especially, the diagnostic accuracy of HRCT is considered to be high. Magnetic resonance imaging (MRI) and positron emission tomography/computed tomography (PET/CT) allow both morphological and functional assessment of the lungs. In addition, biomarkers (e.g., KL-6, CCL2, or MUC5B) are being currently evaluated for the detection and prognostic assessment of ILD. Despite the accuracy of HRCT, invasive diagnostic methods such as bronchoalveolar lavage (BAL) and lung biopsy are still important in clinical practice. However, their therapeutic and prognostic relevance remains unclear. The aim of this review is to give an overview of the individual methods and to present their respective advantages and disadvantages in detecting and monitoring ILD in IRD-patients in the clinical routine.

Assessing the diagnostic value of a potential screening tool for detecting early interstitial lung disease at the onset of inflammatory rheumatic diseases

BACKGROUND

Interstitial lung disease (ILD) is a severe pulmonary complication in inflammatory rheumatic diseases (IRD) and associated with significantly increased morbidity and mortality. That is why ILD screening at a very early stage, at the onset of IRD, is essential. The objective of the present study was to evaluate the diagnostic value and utility of a stepwise approach as a potential ILD screening tool in patients with newly diagnosed IRD.

METHODS

Consecutively, 167 IRD patients were enrolled. To homogenize the study cohort, an age and gender matching was performed. The case-control study included 126 patients with new onset of IRD (mainly connective tissue diseases [CTD], small vessel vasculitis, and myositis). We applied a stepwise screening algorithm in which all patients underwent pulmonary function testing (PFT) and/or additional chest radiography. If there was at least one abnormal finding, pulmonary high-resolution computed tomography (HRCT) was subsequently performed.

RESULTS

With our stepwise diagnostic approach, we identified 63 IRD patients with ILD (ILD group) and 63 IRD patients without ILD (non-ILD group). A reduced diffusing capacity for carbon monoxide (DLCO) < 80% showed a sensitivity of 83.6% and a specificity of 45.8% compared to chest X-ray with 64.2% and 73.6%, respectively, in detecting ILD. The combination of reduced DLCO and chest X-ray revealed a sensitivity of 95.2% and a specificity of 38.7%. The highest sensitivity (95.2%) and specificity (77.4%) were observed for the combination of reduced DLCO, chest X-ray, and pulmonary HRCT. The most common pulmonary abnormalities on HRCT were ground-glass opacities (GGO; 36.5%), followed by non-specific interstitial pneumonia (NSIP; 31.8%) and usual interstitial pneumonia (UIP; 9.5%).

CONCLUSIONS

The combination of reduced DLCO (< 80%), chest X-ray, and pulmonary HRCT yielded the highest sensitivity and specificity in detecting ILD at the onset of IRD. Therefore, this stepwise approach could be a new screening algorithm to identify IRD patients with pulmonary involvement already at the time of the initial IRD diagnosis.

Organ Manifestation and Systematic Organ Screening at the Onset of Inflammatory Rheumatic Diseases

BACKGROUND

Inflammatory rheumatic diseases (IRD) are often associated with the involvement of various organs. However, data regarding organ manifestation and organ spread are rare. To close this knowledge gap, this cross-sectional study was initiated to evaluate the extent of solid organ manifestations in newly diagnosed IRD patients, and to present a structured systematic organ screening algorithm.

MATERIALS AND METHODS

The study included 84 patients (63 women, 21 men) with newly diagnosed IRD. None of the patients received any rheumatic therapy. All patients underwent a standardised organ screening programme encompassing a basic screening (including lungs, heart, kidneys, and gastrointestinal tract) and an additional systematic screening (nose and throat, central and peripheral nervous system) on the basis of clinical, laboratory, and immunological findings.

RESULTS

Represented were patients with connective tissue diseases (CTD) (72.6%), small-vessel vasculitis (16.7%), and myositis (10.7%). In total, 39 participants (46.5%) had one or more organ manifestation(s) (one organ, 29.7%; two organs, 10.7%; ≥three organs, 6.0%). The most frequently involved organs were the lungs (34.5%), heart (11.9%), and kidneys (8.3%). Lastly, a diagnostic algorithm for organ manifestation was applied.

CONCLUSION

One-half of the patients presented with a solid organ involvement at initial diagnosis of IRD. Thus, in contrast to what has been described in the literature, organ manifestations were already present in a high proportion of patients at the time of diagnosis of IRD rather than after several years of disease. Therefore, in IRD patients, systematic organ screening is essential for treatment decisions.