[Linguistic Validation of the "German Lung Fibrosis Health Related Quality of Life Questionnaire"]. / Sprachliche Validierung des Fibrose-Fragebogens zur Erfassung der Lebensqualität bei Patienten mit idiopathischer Lungenfibrose und idiopathischer nichtspezifischer interstitieller Pneumonie.

Health status and quality of life are impaired in patients with idiopathic pulmonary fibrosis (IPF) and idiopathic non-specific interstitial fibrosis (iNSIP). In Germany exists only the K-BILD questionnaire for patients with ILD 1 in a professional translation by Kreuter et al. 2 This questionnaire focuses on the main problems in patients with progressive lung fibrosis in a limited manner. Therefore a new quality of life questionnaire for patients with idiopathic pulmonary fibrosis was developed and linguistically validated. METHODS: The linguistic validation of our questionnaire was carried out in a multistage process in collaboration with the developer of the questionnaire and bilingual, professional translators. Review by the developers and back translations as well as clinical assessment by IPF- and iNSIP-patients ensured that the translated questionnaire reflected the intention of the original English version of our questionnaire.Cross-validation was carried out with the St. Georges Respiratory Questionnaire (SGRQ). RESULTS: The new questionnaire concerning the health status was composed in English and German language. The questions cover five scales (sensitivity, selectivity and symptoms like breathlessness and cough and a visual analog scale on general health status) with 23 items. CONCLUSIONS: The results show that the FFB maps the special needs of the patients with IPF and iNSIP well and can support clinical and scientific questions and can be helpful in monitoring the clinical course.

[Complications after Indwelling Pleural Catheter Implant for Symptomatic Recurrent Benign and Malignant Pleural Effusions]. / Komplikationen nach pleuralem getunnelten Dauerkatheter bei symptomatischen rezidivierenden benignen und malignen Pleuraergüssen.

BACKGROUND: Implant of indwelling pleural catheters (IPC) represents an established therapy method in addition to pleurodesis for symptomatic recurrent benign and malignant pleural effusions (BPE and MPE).There are only few studies on IPC safety during follow-up, especially with regard to infection and pneumothorax rates.The aim of our investigation was to determine the complication frequency after IPC implant and its predictive factors in patients with BPE vs. MPE. METHODS: Retrospective analysis of all IPC implantations in the pneumology department at the University Hospital Dresden during 2015 - 2018. RESULTS: An IPC was implanted in 86 patients (43 m/f each; age 66.9 ±â€Š13.3 years) with symptomatic BPE and MPE. BPE and MPE was present in 12.8 % (11/86) and 87.2 % (75/86) of the patients, respectively.A predominantly small and asymptomatic pneumothorax was detectable as an immediate complication in 43/86 (50 %) of patients; 34/43 (79 %) of patients did not require any specific therapy. For 9/43 patients, IPC suction was required for a median period of three days; 8/43 patients had a large pneumothorax with partial or complete regression after a median period of two days.Catheter infection developed in 15.1 % (13/86) of the total group and 36.4 % (4/11) of the BPE vs. 12 % (9/75) of the MPE after a median period of 87 (BPE/MPE 116/87) days. This was more common in BPE (p = 0.035), large pneumothorax (4/8 patients; p = 0.015) and longer catheter dwell times (124 ±â€Š112 vs. 71 ±â€Š112 days; p = 0.07). CONCLUSION: Small pneumothoraxes are frequent after IPC implantation, but usually do not require specific therapy. IPC infection was detected in 15.1 % of all patients after a median period of 87 days. This was more common in patients with BPE, longer catheter dwell times and large pneumothorax.

[Chronic Granulomatous Disease: A Rare Differential Diagnosis in Recurrent Pulmonary Infections in Adults]. / Septische Granulomatose als seltene Differenzialdiagnose rezidivierender pulmonaler Infektionen bei Erwachsenen.

Chronic granulomatous disease (CGD) should be considered as a differential diagnosis in children and adolescents with frequent infections, especially when caused by certain specific pathogens.This case report describes a 64-year-old female with multiple recurrent and complicated bronchopulmonary infections, caused by common, but also rare pathogens, autoimmune phenomena, malignancies and recurrent organizing pneumonia (OP) with granulomas. Finally, the patient was diagnosed with p47phox-deficient chronic granulomatous disease (CGD).Individuals with a primary immunodeficiency may survive multiple complications and may be diagnosed at an advanced age especially if the affected structure shows residual activity. When confronted with patients with recurrent bronchopulmonary infections, especially with certain specific rare pathogens, in combination with organizing pulmonary granulomas as well as autoimmune phenomena, CGD should be considered even in elderly patients. Delayed diagnosis significantly increases mortality and morbidity in such cases.

[Large Pneumothorax in a Sleep Apnea Patient with CPAP without Previously Known Lung and Thoracic Diseases - a Case Report]. / Großer Pneumothorax unter CPAP-Therapie beim Schlafapnoepatienten ohne vorbekannte Lungen- und Thoraxerkrankungen ­ ein Fallbericht.

CPAP is the most common treatment for obstructive sleep apnea.Serious complications from this treatment are very rare. Pneumothorax following lung barotrauma under CPAP therapy has been described in case reports only in patients with pre-existing lung and thoracic diseases.A 68-year-old sleep apnea patient without pre-existing lung or thoracic diseases and with established CPAP therapy since many years was admitted to the hospital after a severe thoracic pain event with persistent shortness of breath. Chest radiograph and computed tomography showed an extensive right-sided pneumothorax with basal bullous emphysema. After surgical treatment of the secondary spontaneous pneumothorax, on the third postoperative day CPAP with reduced pressure was re-introduced with satisfactory sleep apnea findings and without pneumothorax recurrence.As possible cause of pneumothorax in the patient, alveolar inflammatory changes due to over-distention and increased pressure in the alveoli was assumed, which can occur after years of CPAP treatment with gradual pressure increase.In summary, in sleep apnea patients treated with CPAP for years, after sudden onset of thoracic pain and shortness of breath possible spontaneous pneumothorax should be considered.

[German Guideline for Idiopathic Pulmonary Fibrosis]. / S2K-Leitlinie zur Diagnostik der idiopathischen Lungenfibrose.

Idiopathic pulmonary fibrosis (IPF) is a severe and often fatal disease. Diagnosis of IPF requires considerable expertise and experience. Since publication of the international IPF guideline in the year 2011 and Update 2018 several studies and technical advances occurred, which made a new assessment of the diagnostic process mandatory. In view of the antifibrotic drugs which have been approved for the treatment of IPF patients, the goal of this guideline is to foster early, confident and effective diagnosis of IPF. The guideline focusses on the typical clinical setting of an IPF patient and provides tools to exclude known causes of interstitial lung disease including standardised questionnaires, serologic testing and cellular analysis of bronchoalveolar lavage. High resolution computed tomography remains crucial in the diagnostic work-up. If it is necessary to obtain specimen for histology transbronchial lung cryobiopsy is the primary approach, while surgical lung biopsy is reserved for patients who are fit for it and in whom bronchoscopic diagnosis did not provide the information needed. Despite considerable progress, IPF remains a diagnosis of exclusion and multidisciplinary discussion remains the golden standard of diagnosis.

Impact of TP53 mutation status on systemic treatment outcome in ALK-rearranged non-small-cell lung cancer.

Background: We analyzed whether co-occurring mutations influence the outcome of systemic therapy in ALK-rearranged non-small-cell lung cancer (NSCLC). Patients and methods: ALK-rearranged stage IIIB/IV NSCLC patients were analyzed with next-generation sequencing and fluorescence in situ hybridization analyses on a centralized diagnostic platform. Median progression-free survival (PFS) and overall survival (OS) were determined in the total cohort and in treatment-related sub-cohorts. Cox regression analyses were carried out to exclude confounders. Results: Among 216 patients with ALK-rearranged NSCLC, the frequency of pathogenic TP53 mutations was 23.8%, while other co-occurring mutations were rare events. In ALK/TP53 co-mutated patients, median PFS and OS were significantly lower compared with TP53 wildtype patients [PFS 3.9 months (95% CI: 2.4-5.6) versus 10.3 months (95% CI: 8.6-12.0), P < 0.001; OS 15.0 months (95% CI: 5.0-24.9) versus 50.0 months (95% CI: 22.9-77.1), P = 0.002]. This difference was confirmed in all treatment-related subgroups including chemotherapy only [PFS first-line chemotherapy 2.6 months (95% CI: 1.3-4.1) versus 6.2 months (95% CI: 1.8-10.5), P = 0.021; OS 2.0 months (95% CI: 0.0-4.6) versus 9.0 months (95% CI: 6.1-11.9), P = 0.035], crizotinib plus chemotherapy [PFS crizotinib 5.0 months (95% CI: 2.9-7.2) versus 14.0 months (95% CI: 8.0-20.1), P < 0.001; OS 17.0 months (95% CI: 6.7-27.3) versus not reached, P = 0.049] and crizotinib followed by next-generation ALK-inhibitor [PFS next-generation inhibitor 5.4 months (95% CI: 0.1-10.7) versus 9.9 months (95% CI: 6.4-13.5), P = 0.039; OS 7.0 months versus 50.0 months (95% CI: not reached), P = 0.001). Conclusions: In ALK-rearranged NSCLC co-occurring TP53 mutations predict an unfavorable outcome of systemic therapy. Our observations encourage future research to understand the underlying molecular mechanisms and to improve treatment outcome of the ALK/TP53 co-mutated subgroup.

[DGP Interstitial Lung Disease Patient Questionnaire]. / Patientenfragebogen zur Erfassung der Ursachen interstitieller und seltener Lungenerkrankungen ­ klinische Sektion der DGP.

BACKGROUND: Interstitial lung diseases (ILD) encompass different heterogeneous, mainly chronic diseases of the pulmonary interstitium and/or alveoli with known and unknown reasons. The diagnostic of ILD is challenging and should be performed interdisciplinary. The medical history is of major importance and therefore, in German-speaking countries the Frankfurter Bogen (published in 1985) was utilised to scrutinise the medical history of the patient. This by now more than 30-years-old questionnaire requires a revision with regard to content and language. METHOD: Under the auspices of the clinical section of the DGP the new Interstitial Lung Disease Patient Questionnaire was developed in collaboration amongst pulmonologist, occupational medicine physicians and psychologists and supported by patient support groups. The questionnaire was finally optimised linguistically with the help of patients. RESULTS: The newly developed patient questionnaire for interstitial and rare lung diseases encompasses different domains: initial and current symptoms, medical history questions including prior drug treatments, previous pulmonary and extrapulmonary diseases, potential exposition at home, work and leisure time as well as family history and travelling. CONCLUSION: The newly developed questionnaire can facilitate the diagnosis in patients with suspicion on interstitial lung disease in clinical routine.

[Expert Knowledge and Supporting Advice for the Clinical Use of Nintedanib in Patients with Idiopathic Pulmonary Fibrosis]. / Erfahrungen und unterstützende Hinweise zur Anwendung von Nintedanib bei Patienten mit idiopathischer Lungenfibrose.

In October 2016, a group of German IPF experts were invited by Boehringer Ingelheim to meet in Frankfurt with the aim, (a) to discuss relevant aspects of the management and treatment of idiopathic pulmonary fibrosis (IPF) using nintedanib; and, (b) to provide supportive advice for daily clinical practice with nintedanib. The resulting information compiled in this document is confined to practical issues regarding the use of nintedanib in patients with IPF. Where different therapeutic options were available, the choice of IPF medication was not discussed and the experts alluded to current guidelines for the diagnosis and treatment of IPF.The participants discussed a comprehensive spectrum of clinical questions related to 10 different topics, including patient-related aspects at initiation of IPF therapy, the treatment of anticoagulated IPF patients, and the handling of nintedanib-related adverse events such as gastrointestinal side effects and elevated liver enzymes. In addition, the experts evaluated therapeutic options for IPF patients with continuous disease progression, clinical scenarios that justify discontinuation of nintedanib treatment, and therapeutic options for IPF patients with an acute exacerbation or severe infection. Finally, the participants discussed the handling of nintendanib before/after elective surgical intervention (e. g. lung transplantation) and the current evidence for antifibrotic combination therapy in patients with IPF.For each topic discussed, the resulting information incorporates published evidence from clinical trials. In case of insufficient or lacking evidence, the experts have formulated recommendations based on their personal clinical experience and evaluation.

Olfaction and sinonasal symptoms in patients with CRSwNP and AERD and without AERD: a cross-sectional and longitudinal study.

Oral aspirin challenge (OAC) reveals aspirin-exacerbated respiratory disease (AERD) in approximately 50% of unselected patients with chronic rhinosinusitis with nasal polyposis (CRSwNP). Smell loss is one factor that predicts the outcome of OAC. The present study aims to unveil differences in olfactory function between patients with CRSwNP with and without AERD by means of a validated reliable test for odor threshold, discrimination and identification. Additionally, Beck Depression Inventory (BDI) and Sinonasal Outcome Test 22 (SNOT 22) were applied. 31 patients were tested before and 7 months after OAC and aspirin desensitization in case of diagnosed AERD. AERD was diagnosed in 16 and excluded in 15 patients. Patients with AERD demonstrated significantly more olfactory loss, but no difference in BDI or SNOT 22 at baseline. Olfaction of the groups equalized at follow-up. Sinonasal complaints decreased significantly in patients with AERD, but not in the group without AERD. Olfactory loss is a valuable marker for AERD, but due to the variance of olfactory test results prediction of AERD by exclusively any of the applied olfactory tests appears unreliable.

How to diagnose mould allergy? Comparison of skin prick tests with specific IgE results.

BACKGROUND: Diagnosis of mould allergy is complicated due to the heterogeneity of the test material and the decrease in the number of commercial mould skin test solutions that are currently available. OBJECTIVES: The aim of this study was to compare skin prick tests (SPT) from different manufacturers to one another and concurrently with sIgE tests for Aspergillus fumigatus (Asp f), Cladosporium herbarum (Cla h), Penicillium chrysogenum (Pen ch), Alternaria alternata (Alt a) and Aspergillus versicolor (Asp v) to ascertain a feasible diagnostic procedure for mould sensitization. METHODS: In this multi-centre study, 168 patients with mould exposure and/or mould-induced respiratory symptoms were included. Mould SPT solutions were analysed biochemically and tested in duplicate on patients' arms. Specific IgE (sIgE) concentrations to corresponding mould species and mould mix (mx1) were measured by ImmunoCAP. SPTs in accordance with one another and with sIgE were further considered. The test efficiency was calculated using receiver-operating characteristic (ROC) analysis. RESULTS: Mould sensitization was more frequently detected by the SPT (90 of 168) than by the sIgE tests (56 of 168). Concordances of double SPT positives were only sufficient (≥ 80%) for environmental allergens, two Asp f and three Alt a SPT solutions, whereas all other mould solutions revealed concordances < 80%. The antigen content of SPT solutions was positively associated with concordant SPT double values as well as with sIgE. Taking sIgE as the 'positive standard', all mould SPT solutions revealed test efficiencies > 80%, but varied up to 20% in sensitivity and positive predictive value with the exception of Alt a. CONCLUSIONS: SPT solutions are sensitive and essential diagnostic tools for the detection of mould sensitization. Our recommendation for diagnosis would be to test at least Alt a, Asp f and Pen ch using SPT and additional sIgE test to mx1.

Occupational hypersensitivity pneumonitis: an EAACI position paper.

The aim of this document was to provide a critical review of the current knowledge on hypersensitivity pneumonitis caused by the occupational environment and to propose practical guidance for the diagnosis and management of this condition. Occupational hypersensitivity pneumonitis (OHP) is an immunologic lung disease resulting from lymphocytic and frequently granulomatous inflammation of the peripheral airways, alveoli, and surrounding interstitial tissue which develops as the result of a non-IgE-mediated allergic reaction to a variety of organic materials or low molecular weight agents that are present in the workplace. The offending agents can be classified into six broad categories that include bacteria, fungi, animal proteins, plant proteins, low molecular weight chemicals, and metals. The diagnosis of OHP requires a multidisciplinary approach and relies on a combination of diagnostic tests to ascertain the work relatedness of the disease. Both the clinical and the occupational history are keys to the diagnosis and often will lead to the initial suspicion. Diagnostic criteria adapted to OHP are proposed. The cornerstone of treatment is early removal from exposure to the eliciting antigen, although the disease may show an adverse outcome even after avoidance of exposure to the causal agent.

[Position Paper: Significance of the Forced Vital Capacity in Idiopathic Pulmonary Fibrosis]. / Positionspapier zur Bedeutung der forcierten Vitalkapazität für Patienten mit idiopathischer Lungenfibrose (IPF).

Spirometry is a highly standardized method which allows to measure the forced vital capacity (FVC) with high precision and reproducibility. In patients with IPF FVC is directly linked to the disease process which is characterized by scaring of alveoli and shrinkage of the lungs. Consequently, there is ample evidence form clinical studies that the decline of FVC over time is consistently associated with mortality in IPF. As for the first time effective drugs for the treatment of IPF are available it becomes obvious that in studies which could demonstrate that the drug reduces FVC decline, a numerical effect on mortality was also observed, while in one study where a significant effect on FVC decline was missed, there was also no change in mortality. Based on these studies FVC decline is a validated surrogate of mortality in IPF. It is concluded that FVC decline is not only accepted as an endpoint of clinical treatment trials in IPF but is also valid as a patient related outcome parameter which should be considered for the assessment of the efficacy of an IPF drug.

Tolerated sting challenge in patients on Hymenoptera venom immunotherapy improves health-related quality of life.

BACKGROUND: Sting challenge with a live insect remains the best test for proving the efficacy of immunotherapy in Hymenoptera allergy. OBJECTIVE: We studied the impact of tolerated sting challenge on quality of life. PATIENTS AND METHODS: In this prospective study, data were collected via self-report questionnaires completed by consenting patients with Hymenoptera venom allergy on venom immunotherapy before and after a sting challenge. RESULTS: The study population comprised 100 adult patients (82 with yellow jacket allergy and 18 with honeybee allergy) who participated between September 2009 and November 2010. After the sting challenge, the score on the Vespid Allergy Quality of Life Questionnaire revealed a statistically significant improvement (mean [SD] change, 0.73 [0.98]; P < .0001; 95% CI, 0.52-0.94). This improvement was independent of the patients' gender and age and the severity of the initial anaphylactic reaction. A statistically significant improvement was documented in 2 subgroups of the Short Form 36 Health Survey (physical functioning, mean change, -5.78 [25.23]; P = .038; 95% CI, -11.22 to -0.34; vitality, mean change -4.29 [12.49]; P =.002; 95% CI, -7.02 to -1.57). CONCLUSIONS: Sting challenge results in a significant improvement in disease-specific quality of life and subgroups of general quality of life in patients allergic to Hymenoptera venom receiving established venom immunotherapy.

[Medical care for allergic disorders in Germany: a paradox]. / Allergologische Versorgung in Deutschland: ein Paradoxon.

Medical care for allergic patients in Germany is decreasing, although the prevalence of allergic disorders continues to rise. This article describes the magnitude and the causes of this paradox. In addition, the consequences of this phenomenon for respiratory medicine and for the diagnosis and therapy of asthma are discussed.

Tolerability to etoricoxib in patients with aspirin-exacerbated respiratory disease.

BACKGROUND: The use of selective cyclooxygenase (COX) 2 inhibitors as an alternative to aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) has been suggested for patients with aspirin-exacerbated respiratory disease (AERD). OBJECTIVE: To evaluate tolerability to etoricoxib, a second-generation COX-2 inhibitor with high in vitro selectivity for COX-2 in patients with AERD. METHODS: We conducted a retrospective review of patients with suspected aspirin intolerance seen between October 2007 and April 2012. Single-blind, placebo-controlled oral challenges with increasing doses of aspirin and etoricoxib were performed on 3 different days. RESULTS: Of 262 patients with suspected aspirin intolerance, 248 underwent challenge testing with aspirin and 122 (49.2%) showed positive test results. In 104 of these aspirin-sensitive patients, etoricoxib was tested as an alternative drug and was tolerated in all but 3 (2.9%), who developed a positive asthmatic reaction. CONCLUSIONS: The highly selective COX-2 inhibitor etoricoxib was tolerated in most but not all patients tested. An oral provocation test is therefore recommended before prescribing etoricoxib for patients with AERD.

Tolerability to Etoricoxib in Patients With Aspirin-Exacerbated Respiratory Disease

Introducción: El uso de inhibidores selectivos de la cicloxigenasa-2 (COX-2) como alternativa a la aspirina y otros analgésicos antiinflamatorios no-esteroideos (AINEs) puede ser una alternativa terapeútica para pacientes con enfermedad respiratoria exacerbada por aspirina (EREA). Objetivo: Evaluar la tolerancia a etericoxib, un inhibidor de segunda generación de la COX-2 con alta selectividad in vitro para COX-2, en pacientes con EREA. Para ello se realizó una revisión retrospectiva de pacientes con sospecha de intolerancia a aspirina vistos entre 10/2007 y 04/2012. Se realizaron pruebas de provocación oral controladas con dosis crecientes de aspirina y etericoxib en tres días diferentes. Resultados: De los 262 pacientes con sospecha de intolerancia a aspirina, 248 fueron sometidos a prueba de provocación con aspirina y 122 (49,2%) mostraron un resultado positivo. En 104 de estos, el etericoxib se testó como un medicamento alternativo y fue tolerado en todos, excepto en 3 pacientes (2,9%) que desarrollaron una reacción asmática. Conclusión: El etericoxib se toleró en la mayoría de los pacientes estudiados. Es recomendable una prueba de provocación antes de indicar este medicamento en el tratamiento de pacientes con EREA (AU)

Background: The use of selective cyclooxygenase (COX) 2 inhibitors as an alternative to aspirin and other nonsteroidal anti-inflamatory drugs (NSAIDs) has been suggested for patients with aspirin-exacerbated respiratory disease (AERD). Objective: To evaluate tolerability to etoricoxib, a second-generation COX-2 inhibitor with high in vitro selectivity for COX-2 in patients with AERD. Methods: We conducted a retrospective review of patients with suspected aspirin intolerance seen between October 2007 and April 2012. Single-blind, placebo-controlled oral challenges with increasing doses of aspirin and etoricoxib were performed on 3 different days. Results: Of 262 patients with suspected aspirin intolerance, 248 underwent challenge testing with aspirin and 122 (49.2%) showed positive test results. In 104 of these aspirin-sensitive patients, etoricoxib was tested as an alternative drug and was tolerated in all but 3 (2.9%), who developed a positive asthmatic reaction. Conclusions: The highly selective COX-2 inhibitor etoricoxib was tolerated in most but not all patients tested. An oral provocation test is therefore recommended before prescribing etoricoxib for patients with AERD (AU)

[Retrospective analysis of tuberculosis caused by Mycobacterium bovis 2004 - 2008]. / Retrospektive Analyse von Tuberkuloseerkrankungen durch Mycobacterium bovis 2004 - 2008.

BACKGROUND: mycobacterium bovis is a rare cause of tuberculosis in Germany. Epidemiological data are sparse. METHODS: we have carried out a retrospective analysis of all patients diagnosed with tuberculosis caused by M. BOVIS in a pneumological referral centre between 2004 and 2008. RESULTS: M. bovis was isolated in 8 out of 203 (3,9  %) patients with a new diagnosis of tuberculosis. The median age of these patients was 69 years, and 7 out of 8 showed risk factors for reactivation of a latent tuberculosis infection. In 4 patients (50  %) an extrapulmonary manifestation was present. All isolates of M. bovis were resistant to pyrazinamide, one isolate had an additional resistance to isoniazide. In 6 out of 8 patients prolonged tuberculostatic treatment of 8 - 12 months was recommended. CONCLUSIONS: the proportion of tuberculosis caused by M. bovis was higher than that reported for Germany (3.9 vs. 1,5 %). Predominantly elderly patients with risk factors for reactivation of a latent tuberculosis infection were affected. In accordance with the literature a high rate of extrapulmonary manifestations was detected. Because of the genetic resistance of M. bovis to pyrazinamide prolonged antimycobacterial treatment is recommended.

Rheumatoid pneumoconiosis (Caplan's syndrome).

In 1953, Caplan described a characteristic radiographic pattern in coal miners with rheumatoid arthritis (RA) that was distinct from the typical progressive massive fibrosis pattern of coalworkers' pneumoconiosis. It consists of multiple well-defined rounded nodules on chest X-ray, from about 0.5 to about several centimetres in diameter, distributed throughout the lungs but predominantly at the lung periphery. Lesions appear often in crops, may coalesce and form a larger confluent nodule. Nodules often cavitate or calcify. They typically occur in the setting of pre-existing mild pneumoconiosis, but pneumoconiosis is not a prerequisite. The onset of the nodules is typically sudden, and their course varies thereafter, ranging from regression to progression. Histologically, the nodules have a characteristic appearance and are distinguishable from silicotic nodules or progressive massive fibrosis. Individual susceptibility is considered to play a role in the development of the disease. However, the pathogenetic link between exposure to silica, pneumoconiosis and RA has not been clarified conclusively. This review summarizes history, definition and current knowledge on epidemiology, pathology, pathophysiology, clinical presentation and treatment of Caplan's syndrome.