Pulmonary disorders induced by monoclonal antibodies in patients with rheumatologic autoimmune diseases

Safety risks of interstitial lung disease upon real-world usage of Janus kinase inhibitors and biologics for patients with autoimmune diseases: epidemiological study using nationwide electronic medical record database in Japan

Although Janus kinase inhibitor (JAKi) therapy is used for patients with autoimmune diseases (AD), one safety concern, interstitial lung disease (ILD), is life-threatening. We evaluated actual usage of JAKi and safety upon JAKi treatment, in an epidemiological retrospective cohort study utilizing the electronic medical record database in Japan. Among 391,565 AD patients, we analyzed data of new-users receiving JAKi or tumor necrosis factor alpha inhibitor (TNFi)/biologics during the period July 2013-May 2022. ILD (ICD10: J70.2, J70.3, J70.4 and J84) criteria were defined: new-ILD (1) and new-ILD (2) which differed in the latter's prompter therapeutics cessation upon ILD development. We analyzed ILD occurrence and death, ILD cumulative incidence by the Kaplan-Meier method, and hazard ratio (HR) by the Cox model, for 957 JAKi and 3931 TNFi users. JAKi use has become widespread amidst additional drug-development. Among JAKi users, two-year new-ILD (2) incidence, at 1.4%, was higher than for TNFi users (risk ratio: new-ILD (2) 1.75, death 2.31). Cumulative incidence (2.9% in 20.48 days) was also significantly higher (log-rank test p = .013, HR 2.23 (95% CI 1.16-4.27)); risk factors estimated by HR included JAKi (2.14), rheumatoid arthritis (4.94), diabetes mellitus (2.67) and cerebrovascular disease (2.86). ILD screening is essential.

Focus on Anti-Tumour Necrosis Factor (TNF)-α-Related Autoimmune Diseases

Anti-tumour necrosis factor (TNF)-α agents have been increasingly used to treat patients affected by inflammatory bowel disease and dermatological and rheumatologic inflammatory disorders. However, the widening use of biologics is related to a new class of adverse events called paradoxical reactions. Its pathogenesis remains unclear, but it is suggested that cytokine remodulation in predisposed individuals can lead to the inflammatory process. Here, we dissect the clinical aspects and overall outcomes of autoimmune diseases caused by anti-TNF-α therapies.

Rheumatoid arthritis related interstitial lung disease - improving outcomes over 25 years: a large multicentre UK study

OBJECTIVE

This study explores whether the prognosis of interstitial lung disease in rheumatoid arthritis (RA-ILD) has improved over time and assesses the potential influence of drug therapy in a large multicentre UK network.

METHODS

We analysed data from 18 UK centres on patients meeting criteria for both RA and ILD diagnosed over a 25-year period. Data included age, disease duration, outcome and cause of death. We compared all cause and respiratory mortality between RA controls and RA-ILD patients, assessing the influence of specific drugs on mortality in four quartiles based on year of diagnosis.

RESULTS

A total of 290 RA-ILD patients were identified. All cause (respiratory) mortality was increased at 30% (18%) compared with controls 21% (7%) (P =0.02). Overall, prognosis improved over quartiles with median age at death rising from 63 years to 78 years (P =0.01). No effect on mortality was detected as a result of DMARD use in RA-ILD. Relative risk (RR) of death from any cause was increased among patients who had received anti-TNF therapy [2.09 (1.1-4.0)] P =0.03, while RR was lower in those treated with rituximab [0.52(0.1-2.1)] or mycophenolate [0.65 (0.2-2.0)]. Patients receiving rituximab as their first biologic had longer three (92%), five (82%) and seven year (80%) survival than those whose first biologic was an anti-TNF agent (82%, 76% and 64%, respectively) (P =0.037).

DISCUSSION

This large retrospective multicentre study demonstrates survival of patients with RA-ILD has improved. This may relate to the increasing use of specific immunosuppressive and biologic agents.

Rheumatoid arthritis-interstitial lung disease: manifestations and current concepts in pathogenesis and management

Rheumatoid arthritis (RA) is a systemic inflammatory disorder, with the most common extra-articular manifestation of RA being lung involvement. While essentially any of the lung compartments can be affected and manifest as interstitial lung disease (ILD), pleural effusion, cricoarytenoiditis, constrictive or follicular bronchiolitis, bronchiectasis, pulmonary vasculitis, and pulmonary hypertension, RA-ILD is a leading cause of death in patients with RA and is associated with significant morbidity and mortality. In this review, we focus on the common pulmonary manifestations of RA, RA-ILD and airway disease, and discuss evolving concepts in the pathogenesis of RA-associated pulmonary fibrosis, as well as therapeutic strategies, and have revised our previous review on the topic. A rational clinical approach for the diagnosis and management of RA-ILD, as well as an approach to patients with clinical worsening in the setting of treatment with disease-modifying agents, is included. Future directions for research and areas of unmet need in the realm of RA-associated lung disease are raised.

Rheumatoid arthritis (RA) is a systemic inflammatory disorder, with the most common extra-articular manifestation of RA being lung involvement. RA-ILD is a leading cause of death in RA patients and is associated with significant morbidity and mortality.https://bit.ly/3w6oY4i

Biologic and advanced immunomodulating therapeutic options for sarcoidosis: a clinical update

Introduction: Sarcoidosis is a multi-organ disease with a wide range of clinical manifestations and outcomes. A quarter of sarcoidosis patients require long-term treatment for chronic disease. In this group, corticosteroids and cytotoxic agents be insufficient to control diseaseAreas covered: Several biologic agents have been studied for treatment of chronic pulmonary and extra-pulmonary disease. A review of the available literature was performed searching PubMed and an expert opinion regarding specific therapy was developed.Expert opinion: These agents have the potential of treating patients who have progressive disease. Many of these agents have different mechanisms of action, response rates, and toxicity profiles.

The risk of interstitial lung disease during biological treatment in Japanese patients with psoriasis

BACKGROUND

With the increasing use of biological agents for the treatment of psoriasis, the numbers of patients with interstitial lung disease (ILD) associated with biologics have also increased. Many of these cases were associated with tumour necrosis factor (TNF)-α inhibitors, but cases associated with other families of biologics have also been reported in Japan.

AIM

To analyse the background factors of patients who developed ILD, and to discuss better management of biological treatment.

METHOD

We reviewed 246 patients with psoriasis who were treated with biological agents in our department to identify any pulmonary adverse events (AEs). Data on patients who developed ILD were extracted to analyse background factors, clinical type of psoriasis, time to onset of ILD, pre-existing ILD, smoking habit and prescribed drugs.

RESULTS

Pulmonary AEs were seen in 22 cases, of which 11 were diagnosed as drug-induced ILD. The causative drugs were mainly TNF-α inhibitors, accounting for eight cases (six treated with infliximab, two with adalimumab). The remaining three cases were associated with secukinumab, ustekinumab and ixekizumab (n = 1 each). Notably, these three cases also had a history of drug-induced ILD.

CONCLUSION

Patients with a history of drug-induced ILD seem to be more susceptible to developing another ILD induced by biologics, even if treated with interleukin-17 inhibitors. Thorough screening of risk factors and evaluation for eligibility, and careful monitoring during treatment are the best solutions to avoid serious pulmonary AE. Early detection and precise diagnosis of pulmonary AEs, especially differentiation from infectious diseases, is essential for managing biological treatment.

Thoracic Manifestations of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is commonly associated with pulmonary disease that can affect any anatomic compartment of the thorax. The most common intrathoracic manifestations of RA include interstitial lung disease, airway disease, pleural disease, rheumatoid nodules, and drug-induced toxicity. Patients with RA with thoracic involvement often present with nonspecific respiratory symptoms, although many are asymptomatic. Therefore, clinicians should routinely consider pulmonary disease when evaluating any patient with RA, particularly one with known risk factors. The optimal screening, diagnostic, and treatment strategies for RA-associated pulmonary disease remain uncertain and are the focus of ongoing investigation.

Identification of differentially expressed genes and signaling pathways using bioinformatics in interstitial lung disease due to tyrosine kinase inhibitors targeting the epidermal growth factor receptor

Interstitial lung disease (ILD) is a rare but lethal adverse effect of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) treatment. The specific mechanism of this disease is not fully understood. To systematically analyze genes associated with EGFR-TKI induced ILD, gene data of EGFR-TKI induced ILD were extracted initially using text mining, and then the intersection between genes from text mining and Gene Expression Omnibus (GEO) dataset was taken for further protein-protein interaction (PPI) analysis using String-bd database. Go ontology (GO) and pathway enrichment analysis was also conducted based on Database of Annotation, Visualization and Integrated Discovery (DAVID) platform. The PPI network generated by STRING was visualized by Cytoscape, and the topology scores, functional regions and gene annotations were analyzed using plugins of CytoNCA, molecular complex detection (MCODE) and ClueGo. 37 genes were identified as EGFR-TKI induced ILD related. Gene enrichment analysis yield 18 enriched GO terms and 12 associated pathways. A PPI network that included 199 interactions for a total of 35 genes was constructed. Ten genes were selected as hub genes using CytoNCA plugin, and four highly connected clusters were identified using MCODE plugin. GO and pathway annotation analysis for the cluster one revealed that five genes were associated with either response to dexamethasone or with lung fibrosis, including CTGF, CCL2, IGF1, EGFR and ICAM1. Our data might be useful to reveal the pathological mechanisms of EGFR-TKI induced ILD and provide evidence for the diagnosis and treatment in the future.

Stop Being So Sensitive: An Exceptionally Rare Report of Ustekinumab-Induced Sub-acute Hypersensitivity Pneumonitis

Hypersensitivity pneumonitis (HSP) is a rare syndrome characterised by granulomatous inflammatory lung disease due to repeated sensitisation from a specific antigen. We present the case of a 61-year old male veteran with a history of nodular eczema who presented with 2 weeks of progressive dyspnoea on exertion and pleuritic chest pain. The patient was started on ustekinumab 5 weeks prior to presentation. Initial workup revealed ground-glass opacities on computed tomography (CT) scan of the chest. Cardiac workup was unrevealing with a normal myocardial perfusion stress test. The patient was started on inhaled corticosteroids and albuterol for reactive airway disease. Due to the persistence of symptoms despite treatment, the patient underwent bronchoscopy with bronchoalveolar lavage (BAL), transbronchial biopsy and endobronchial ultrasound-guided biopsy (EBUS). Bronchoscopy showed normal appearing airways of both right and left lungs. The BAL was remarkable for chronic inflammation and pulmonary macrophages. The BAL cell count differential was 1% granulocytes, 50% lymphocytes, 17% eosinophils and 32 mononuclear cells. The pathology from the mediastinal lymph nodes showed reactive inflammatory cells and no malignancy. The pathology from the transbronchial biopsy of the anterior basilar segment of the right lower lobe showed organising pneumonia with occasional ill-defined granulomas that stained negative for Acid Fast Bacilli (AFB) and Grocott's methenamine (GMS) appeared to be consistent with hypersensitivity pneumonitis. Based on the pathological diagnosis of HSP, the patient was managed with discontinuation of ustekinumab, with subsequent improvement of his symptoms. To our knowledge, this is the first report suggesting ustekinumab, like other biological therapies, has the potential to cause HSP.

Biologic response modifiers: Indications, implications, and insights

The field of biologic immune modulators is currently mushrooming at a dizzying pace. Although most of these biologics are tested and approved for one or a few indications, their unanticipated side effects and off-label use have contributed significantly to our understanding of basic immune mechanisms, the involvement of cytokines in several apparently nonimmunologic diseases, and the importance of compartmentalized immune responses. In this review we attempt to give a bird's-eye view of the major biologics and to highlight insights and implications derived from their secondary effects and adverse reactions.

Biologics-induced interstitial lung diseases in rheumatic patients: facts and controversies

INTRODUCTION

Interstitial lung disease (ILD) is a common, devastating pulmonary complication. An increased number of reports suggesting that biological disease modifying antirheumatic drugs (DMARDs) induced or exacerbated ILDs in rheumatoid arthritis (RA) patients has garnered increased attention. Areas covered: This article discusses ILDs induced by or exacerbated during biological therapy in RA patients. The article summarizes the efficacy and safety of a variety of licensed and off-label biologics clinically used for rheumatic diseases, focusing on the onset or exacerbation of RA-associated ILDs (RA-ILDs) in RA patients treated with biologics targeting tumor necrosis factor, CD20, interleukin 1 (IL-1) and IL-6 receptors. Additionally, the pathogenesis of RA-ILDs is discussed. Expert opinion: To some extent, the possibility of biologic-induced RA-ILDs increases the difficulty in choosing an optimal regimen for RA treatment with biological agents, as the relationship between biological therapy safety and the induction or exacerbation of RA-ILDs has not been established. A framework to assess baseline disease severity, particularly standardizing the evaluation of the pulmonary condition stage in RA patients and monitoring the outcome during the biological therapy treatment, is highly needed and may substantially help guide treatment decisions and predict the treatment benefits.

Use and effectiveness of tocilizumab among patients with rheumatoid arthritis: an observational study from the British Society for Rheumatology Biologics Register for rheumatoid arthritis

The aims of the present study are to describe the characteristics of rheumatoid arthritis (RA) patients selected for tocilizumab (TCZ), compare the “real-world” effectiveness of TCZ and tumour necrosis factor inhibitors (TNFi) when used as a first biologic and assess the influence of past biologic exposure/concurrent methotrexate (MTX) therapy on post-TCZ treatment outcomes. The British Society for Rheumatology Biologics Register (BSRBR-RA) is a prospective cohort study following RA patients starting biologics in the UK. This includes patients starting TCZ as first or subsequent biologic, alongside biologic-naïve patients starting TNFi. Six-month disease activity and 1-year drug survival were compared between biologic-naïve patients starting TCZ versus TNFi and first-line versus subsequent TCZ users and TCZ users with MTX versus without using regression models adjusted by propensity score. Two hundred seventeen patients started TCZ, and 2419 started TNFi as first biologic. Seven hundred seventy-seven started TCZ after other biologics. First-line TCZ users had a higher prevalence of pulmonary fibrosis and cancer history than TNFi users. The first-line TCZ users were more likely to achieve DAS28 remission at 6 months than first-line TNFi, but other improvement markers were similar. The treatment response at 6 months was similar between subsequent-line TCZ users and first-line users after adjusting for baseline patient differences. Concurrent MTX use was not associated with treatment response in either first- or subsequent-line TCZ users. TCZ has been primarily used as subsequent-line biologic in the UK. When used as first line, the response appears similar to that observed in patients starting TNFi, suggesting that clinical response alone should not decide between initial biologic therapies.

Infection is the major trigger of hemophagocytic syndrome in adult patients treated with biological therapies

INTRODUCTION

Hemophagocytic syndromes (hemophagocytic lymphohistiocytosis, HLH) are characterized by a wide range of etiologies, symptoms, and outcomes, but have a common etiopathogenic pathway leading to organ damage: an excessive inflammatory response. Biological therapies have been proposed as a therapeutic option for refractory HLH, but have also been related to the development of HLH in severe immunosuppressed patients.

OBJECTIVES AND METHODS

The purpose of this study was to analyze the clinical characteristics and outcomes of adult patients who developed HLH after receiving biological therapies.

RESULTS

We identified 30 patients (29 from the PubMed search and one unpublished case), including 19 women and 11 men, with a mean age of 46.5 years. Underlying diseases consisted of rheumatologic/autoimmune diseases in 24 patients and hematological neoplasia in the remaining 6. Biological agents received before the development of HLH were mainly anti-TNF agents (n = 19). Search for microorganisms confirmed systemic infection in 20 (67%) patients, including Mycobacterium tuberculosis (n = 5), cytomegalovirus (CMV) (n = 4), Epstein-Barr virus (EBV) (n = 3), Histoplasma capsulatum (n = 3), Escherichia coli (n = 2), Staphylococcus aureus, Leishmania amastigotes and Brucella melitensis (n = 1, respectively); viral infections were mainly reported in inflammatory bowel disease (IBD) patients. Patients with infections had more frequently received previous immunosuppressive therapies (p = 0.036) and had lower leukocyte counts (p = 0.020) in comparison with patients without associated infections. The outcome was described in 29 patients. After a mean follow-up of 6.3 months, 8 patients died (28%) and 6 had received anti-TNF agents. There was a high mortality rate in patients aged >65 years and those with tuberculosis (62% and 60%, respectively).

CONCLUSIONS

In patients receiving biological therapies who develop HLH, searching for a concomitant infectious process is mandatory, and specific surveillance for EBV/CMV infections (in patients with IBD) and for bacteria, including mycobacteria (in elderly patients receiving anti-TNF therapy), is recommended.

Miscellaneous adverse events with biologic agents (excludes infection and malignancy)

Anti-tumor necrosis factor-α (anti-TNF) agents are frequently used in the treatment of inflammatory bowel disease (IBD). Currently, there are 4 anti-TNF therapies that are Food and Drug Administration-approved for moderate to severe IBD: infliximab, adalimumab, golimumab, and certolizumab pegol. For most noninfectious, nonmalignant adverse events, cessation of anti-TNF therapy typically leads to improvement or resolution of drug-induced complications. In this article, the current knowledge regarding the noninfectious and nonmalignant toxicities associated with anti-TNF agents is summarized.

Bronchoalveolar lavage cellular patterns in monoclonal antibody-induced lung disease

BACKGROUND

The increase in the use of monoclonal antibodies (mAB) as a targeted therapy for a variety of diseases has been accompanied by an increase in reports of interstitial lung abnormalities in treated patients.

OBJECTIVE

Bronchoalveolar lavage (BAL) is routinely performed in these patients to rule out infection, so we sought to determine the BAL cellular pattern in individuals with mAB-induced lung disease (mAB-ILD).

METHODS

We utilized a case-control study design. Among patients treated with mAB, cases were defined as those with otherwise-unexplained interstitial lung abnormalities, which resolved after cessation of treatment, while controls were defined as those with interstitial abnormalities clearly explained by other etiologies.

RESULTS

From 2000 to 2012, we identified 9 cases and 7 controls. The mean age of the cases was 62.6 ± 26 years and 6 were female. The most common radiographic finding was diffuse ground-glass opacities. The most common BAL cellular pattern was mixed inflammation with moderate lymphocytic and mild neutrophilic alveolitis. The cases had a higher mean lymphocyte count than the controls (40.1 ± 32.6 vs. 13.1 ± 25.5, p = 0.008). The rest of the BAL cellular analyses were similar between the 2 groups. The median CD4:CD8 ratio in 7 patients with >15% lymphocytes was 0.9 (0.6-3). There was no significant difference in the CD4:CD8 ratio between the 2 groups.

CONCLUSIONS

Mixed inflammation with moderate lymphocytic and mild neutrophilic alveolitis is the most common BAL cellular pattern in patients with mAB-ILD. Such findings may be useful for the early identification of mAB-ILD.

A roadmap to promote clinical and translational research in rheumatoid arthritis-associated interstitial lung disease

Rheumatoid arthritis (RA) is a systemic inflammatory disorder affecting approximately 1.3 million adults in the United States. Approximately 10% of these individuals with RA have clinically evident interstitial lung disease (RA-ILD), and an additional one-third demonstrate subclinical ILD on chest CT scan. The risk of death for individuals with RA-ILD is three times higher than for patients with RA without ILD, with a median survival after ILD diagnosis of only 2.6 years. Despite the high prevalence and mortality of RA-ILD, little is known about its molecular features and its natural history. At present, we lack a standard validated approach to the definition, diagnosis, risk stratification, and management of RA-ILD. In this perspective, we discuss the importance of clinical and translational research and how ongoing research efforts can address important gaps in our knowledge over the next few years. Furthermore, recommendations are made to design multicenter collaborative studies that will expedite the development of clinical trials designed to decrease the significant morbidity and mortality associated with RA-ILD.

Biologics-induced autoimmune diseases

PURPOSE OF REVIEW

Biological agents are therapies designed to target a specific molecular component of the immune system, and are currently licensed for use in autoimmune rheumatic, digestive, dermatological and systemic diseases. However, their use has been linked with the paradoxical development of autoimmune processes.

RECENT FINDINGS

More than 1500 cases of autoimmune diseases induced by biologics have been reported, including a wide variety of both systemic (lupus, vasculitis, sarcoidosis, antiphospholipid syndrome and inflammatory myopathies) and organ-specific (interstitial lung disease, uveitis, optic neuritis, peripheral neuropathies, multiple sclerosis, psoriasis, inflammatory bowel disease and autoimmune hepatitis) autoimmune processes. Although these processes are overwhelmingly associated with anti-TNF agents, recent cases have been associated with therapies directed against other cytokines, B or T-cells, illustrating that even though targeting a particular immune molecule may be associated with an excellent clinical response in most patients, an unexpected autoimmune response may arise in some cases.

SUMMARY

As the use of biological therapies expands, the number and diversity of induced autoimmune disorders should be expected to increase. Paradoxically, for many of these drug-related processes, current treatment indications include the very biological agent producing the adverse event.

Lung involvement in connective tissue diseases: a comprehensive review and a focus on rheumatoid arthritis

The lungs are frequently involved in Connective Tissue Diseases (CTDs). Interstitial lung disease (ILD) is one of the most common pleuropulmonary manifestations that affects prognosis significantly. In practice, rheumatologists and other physicians tend to underestimate the impact of CTD-ILDs and diagnose respiratory impairment when it has reached an irreversible fibrotic stage. Early investigation, through clinical evidence, imaging and - in certain cases - lung biopsy, is therefore warranted in order to detect a possible ILD at a reversible initial inflammatory stage. In this review, we focus on lung injury during CTDs, with particular attention to ILDs, and examine their prevalence, clinical manifestations and histological patterns, as well as therapeutic approaches and known complications till date. Although several therapeutic agents have been approved, the best treatment is still not certain and additional trials are required, which demand more knowledge of pulmonary involvement in CTDs. Our central aim is therefore to document the impact that lung damage has on CTDs. We will mainly focus on Rheumatoid Arthritis (RA), which - unlike other rheumatic disorders - resembles Idiopathic Pulmonary Fibrosis (IPF) in numerous aspects.

Association between anti-TNF-α therapy and interstitial lung disease

BACKGROUND

Anti-tumor necrosis factor-α (TNF-α) agents have been hypothesized to increase the risk of interstitial lung disease (ILD), including its most severe manifestation, pulmonary fibrosis.

METHODS

We conducted a cohort study among autoimmune disease patients who were members of Kaiser Permanente Northern California, 1998-2007. We obtained therapies from pharmacy data and diagnoses of ILD from review of X-ray and computed tomography reports. We compared new users of anti-TNF-α agents to new users of non-biologic therapies using Cox proportional hazards analysis to adjust for baseline propensity scores and time-varying use of glucocorticoids. We also made head-to-head comparisons between anti-TNF-α agents.

RESULTS

Among the 8417 persons included in the analysis, 38 (0.4%) received a diagnostic code for ILD by the end of follow-up, including 23 of 4200 (0.5%) who used anti-TNF-α during study follow-up, and 15 of 5423 (0.3%) who used only non-biologic therapies. The age-standardized and gender-standardized incidence rate of ILD, per 100 person-years, was 0.21 [95% confidence interval (CI) 0-0.43] for rheumatoid arthritis and appreciably lower for other autoimmune diseases. Compared with the use of non-biologic therapies, use of anti-TNF-α therapy was not associated with a diagnosis of ILD among patients with rheumatoid arthritis (adjusted hazard ratio, 1.03; 95%CI 0.51-2.07), nor did head-to-head comparisons across anti-TNF-α agents suggest important differences in risk, although the number of cases available for analysis was limited.

CONCLUSION

The study provides evidence that compared with non-biologic therapies, anti-TNF-α therapy does not increase the occurrence of ILD among patients with autoimmune diseases and informs research design of future safety studies of ILD.

Drug induced interstitial lung disease

With an increasing number of therapeutic drugs, the list of drugs that is responsible for severe pulmonary disease also grows. Many drugs have been associated with pulmonary complications of various types, including interstitial inflammation and fibrosis, bronchospasm, pulmonary edema, and pleural effusions. Drug-induced interstitial lung disease (DILD) can be caused by chemotherapeutic agents, antibiotics, antiarrhythmic drugs, and immunosuppressive agents. There are no distinct physiologic, radiographic or pathologic patterns of DILD, and the diagnosis is usually made when a patient with interstitial lung disease (ILD) is exposed to a medication known to result in lung disease. Other causes of ILD must be excluded. Treatment is avoidance of further exposure and systemic corticosteroids in patients with progressive or disabling disease.

[Lung disease associated with connective tissue disease]

Connective tissue diseases are often associated with lung diseases that lead to high morbidity and mortality, including interstitial disease, airway disease, pleural lesions, and vascular disease. High resolution CT has high sensitivity for detecting parenchymal disease and potentially reversible lesions, helping to guide treatment. This article emphasizes interstitial pneumonia in association with connective tissue disease and the characteristics that differentiate this entity from idiopathic types. Likewise, we review the most common pulmonary manifestations of each connective tissue disease with the aim of providing the radiologist with a practical approach to the diagnosis and management of these diseases in daily clinical practice.

Drug-induced interstitial lung disease: mechanisms and best diagnostic approaches

Drug-induced interstitial lung disease (DILD) is not uncommon and has many clinical patterns, ranging from benign infiltrates to life-threatening acute respiratory distress syndrome. There are two mechanisms involved in DILD, which are probably interdependent: one is direct, dose-dependent toxicity and the other is immune-mediated. Cytotoxic lung injury may result from direct injury to pneumocytes or the alveolar capillary endothelium. Drugs can induce all types of immunological reactions described by Gell and Coombs; however, most reactions in immune-mediated DILD may be T cell-mediated.

DILD can be difficult to diagnose; diagnosis is often possible by exclusion alone. Identifying the causative drug that induces an allergy or cytotoxicity is essential for preventing secondary reactions.

One method to confirm the diagnosis of a drug-induced disease is re-exposure or re-test of the drug. However, clinicians are reluctant to place patients at further risk of illness, particularly in cases with severe drug-induced diseases. Assessment of cell-mediated immunity has recently increased, because verifying the presence or absence of drug-sensitized lymphocytes can aid in confirmation of drug-induced disease. Using peripheral blood samples from drug-allergic patients, the drug-induced lymphocyte stimulation test (DLST) and the leukocyte migration test (LMT) can detect the presence of drug-sensitized T cells. However, these tests do not have a definite role in the diagnosis of DILD. This study explores the potential of these new tests and other similar tests in the diagnosis of DILD and provides a review of the relevant literature on this topic.

A case of capecitabine-induced sarcoidosis

Sarcoidosis is an inflammatory disease involving multiple-organs with an unknown cause. The new onset of sarcoidosis associated with therapeutic agents has been observed in 3 clinical settings; tumor necrosis factor antagonists in autoimmune rheumatologic diseases, interferon alpha with or without ribavirin in patients with chronic hepatitis C or melanoma, and antineoplastic agent-associated sarcoidosis in patients with hematologic malignancies. Here, we report a female patient who developed sarcoidosis after capecitabine treatment as an adjuvant chemotherapy for sigmoid colon cancer. To our knowledge, this is the first report of a capecitabine-induced sarcoidosis.