Adapting the 2025 ERS/EULAR CTD-ILD guidelines for India: A practical perspective

The 2025 ERS/EULAR clinical practice guidelines for connective tissue disease-associated interstitial lung disease (CTD-ILD) mark a milestone in respiratory and rheumatology medicine. These guidelines, developed by an international panel of experts, provide a structured framework for the diagnosis, monitoring, and treatment of CTD-ILDs. They integrate advances in immunosuppressive and antifibrotic therapy, establish standardized progression criteria, and emphasize multidisciplinary decision-making.

For clinicians in India, where CTD-ILDs are increasingly recognized but frequently diagnosed late, as demonstrated in national ILD registry data and tertiary-care CTD-ILD cohorts,[1,2,3,4] these global recommendations are particularly relevant. This editorial does not aim to develop independent Indian guidelines. Instead, it provides a practical perspective on how the 2025 ERS/EULAR guidelines can be interpreted, implemented, and adapted across India’s diverse healthcare settings. The objective is to highlight real-world challenges documented in Indian studies, system-level considerations, and feasible strategies that can support guideline-aligned care in India.[5]

SYSTEMIC SCLEROSIS–ASSOCIATED ILD (SSC-ILD)

The 2025 ERS/EULAR guidelines identify mycophenolate mofetil (MMF) as the preferred first-line therapy for SSc-ILD, supported by evidence from the Scleroderma Lung Study II, which demonstrated comparable efficacy and improved tolerability versus cyclophosphamide. Cyclophosphamide remains an option in selected situations, particularly in rapidly progressive or refractory disease. For patients who exhibit disease progression despite adequate immunosuppression, nintedanib may be considered as an antifibrotic add-on strategy. High-dose corticosteroids continue to be strongly discouraged because of the established risk of scleroderma renal crisis.[6,7]

From an Indian perspective, clinical cohorts consistently report delayed recognition of SSc-ILD, prolonged empirical corticosteroid exposure, and advanced radiological fibrosis at the time of presentation.[3,4] These findings align with ILD-India registry data documenting late referral pathways and incomplete autoimmune evaluation in early disease.[1,2,8] MMF is increasingly available in generic formulations in tertiary centres, supporting its pragmatic use as a steroid-sparing agent, while cyclophosphamide continues to be used in several public-sector settings, particularly for severe or rapidly progressive presentations. These real-world patterns reinforce the need for early identification pathways, structured multidisciplinary evaluation, steroid-sparing approaches, and routine TB/HBV screening before initiating immunosuppression.[1,2,8]

RHEUMATOID ARTHRITIS-ASSOCIATED ILD (RA-ILD)

The 2025 ERS/EULAR guidelines recommend immunosuppressive options such as mycophenolate mofetil (MMF), azathioprine (AZA), and rituximab (RTX) for RA-ILD, while clarifying that methotrexate (MTX) is not universally contraindicated and may be continued in stable patients without clear evidence of drug-related toxicity. RTX has demonstrated benefit in observational studies and may be considered in progressive RA-ILD, particularly when inflammatory features predominate.[9]

In India, access to RTX varies considerably across centres and is shaped by institutional resources. Concerns regarding MTX-associated pulmonary toxicity persist in routine practice, sometimes leading to premature discontinuation despite lack of confirmatory evidence, which may compromise overall disease control. Wider physician awareness of guideline-supported MTX safety and greater use of affordable generics such as AZA and MMF represent feasible therapeutic approaches in many settings. Additionally, fragmented care pathways between rheumatologists and pulmonologists contribute to delayed ILD recognition, underscoring the need for structured referral processes and collaborative evaluation models.

MYOSITIS-ASSOCIATED ILD

The guidelines emphasize aggressive therapy for rapidly progressive ILD (RP-ILD) in myositis, recommending early initiation of MMF, cyclophosphamide, rituximab, or calcineurin inhibitors, with intravenous immunoglobulin (IVIG) reserved for refractory cases. Prompt recognition of anti-MDA5–positive patients is critical due to their high mortality risk.

In India, diagnosis of myositis-ILD is often delayed, reflecting limited access to comprehensive serology, variable awareness of RP-ILD presentations, and late referral to specialists. Use of IVIG may vary across centres depending on local practices and resource availability. Pragmatic approaches include prioritizing commonly used immunosuppressants, employing simplified serology panels where appropriate, and enabling early referral through tele-MDTs, which can help ensure timely identification and management across diverse healthcare settings.[10]

SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) AND MIXED CONNECTIVE TISSUE DISEASE (MCTD) ILD

The guidelines recommend the use of MMF, AZA, or cyclophosphamide for ILD associated with SLE and MCTD, though high-quality trial data remain limited. Treatment decisions should be individualized, with attention to overlap features and systemic disease activity.

In India, patients frequently present with advanced fibrosis, reflecting delayed disease recognition and late referral pathways. Access to comprehensive autoimmune serology may vary across centres, making it practical in many settings to begin with core panels such as ANA, RF, and anti-CCP, followed by targeted testing where clinically indicated. Strengthening collaborative pathways between pulmonology and rheumatology services is essential to support timely diagnosis and coordinated management.[11]

OVERLAP AND UNDIFFERENTIATED CTD-ASSOCIATED ILD (UCTD-ILD)

The guidelines acknowledge that overlap and UCTD-associated ILD should be approached according to the dominant clinical and radiological phenotype, with immunosuppressive therapy forming the cornerstone of management. Antifibrotics may be considered in progressive fibrotic phenotypes.

In India, these patients are often diagnosed at a later stage, frequently after substantial fibrosis has developed, reflecting delays in recognition and fragmented care pathways. The absence of standardized referral systems can result in patients moving between general physicians, rheumatologists, and pulmonologists without coordinated evaluation. Structured tele-MDTs and participation in ILD registries can support earlier identification and more consistent care pathways across centres.[10,11,12]

After considering disease-specific nuances, a unified implementation framework becomes valuable for translating global recommendations into practical workflows within India’s heterogeneous healthcare ecosystem. The tier-based approach outlined below is intended as a pragmatic model for peripheral hospitals, teaching centres, and tertiary ILD units, rather than a guideline, to facilitate consistent evaluation and decision-making across settings.[10,11,12]

IMPLEMENTATION MODEL FOR INDIA: EVIDENCE-INFORMED, TIERED APPROACH

Implementing CTD-ILD guideline recommendations in India requires a pragmatic, resource-tiered approach grounded in available evidence and national programme experience. Indian ILD cohorts consistently demonstrate delayed diagnosis, empirical and prolonged corticosteroid use, and variability in access to specialist care and investigations.[1,2] The tiered care architecture used in India’s National TB Elimination and NCD programmes offers a practical template for operationalizing CTD-ILD pathways.[13,14]

At peripheral and district hospitals, priority actions include improving ILD suspicion through simple clinical red flags (unexplained dyspnoea, Velcro crackles, CTD manifestations), screening for TB/HBV before initiating steroids, restricting steroid dose and duration, and facilitating timely referral to higher-level centres.[1,13]

Medical colleges can implement a minimal autoimmune panel (ANA, RF, anti-CCP), consider early use of commonly employed steroid-sparing agents (MMF/AZA) where appropriate, and establish regular ILD–rheumatology discussions supported by tele-MDTs.[2,8]

Tertiary ILD centres can provide integrated ILD–rheumatology services, comprehensive autoimmune evaluation, HRCT/DLCO-based staging, and access to advanced therapies where available, while also functioning as referral and training hubs with registry participation.[1,11]

A monitoring strategy based on symptoms, spirometry, and the 6MWT for peripheral centres—with HRCT and DLCO reserved for referral hubs or predefined progression checkpoints—supports resource-sensitive delivery while maintaining consistency with guideline intent.

Tier-based CTD-ILD Care Model for India

Level of Care	Key Barriers (India evidence)	Practical, Feasible Actions
Level of Care	Key Barriers (India evidence)	Practical, Feasible Actions
District/Peripheral centres	Low ILD suspicion; empirical steroid use; limited diagnostics[1,2]	Red-flag checklist (dyspnoea, Velcro crackles, CTD signs); TB/HBV screening; short steroids only when needed; early referral to ILD centre
Medical colleges/State hospitals	Limited rheumatology access; variation in access to extended autoimmune testing[2,11]	Minimal autoimmune panel (ANA, RF, anti-CCP); consider commonly used steroid-sparing agents (MMF/AZA) where appropriate; periodic ILD–rheumatology meetings; tele-MDT with tertiary hub
Tertiary ILD centres	Advanced cases; need for complex immunosuppression and antifibrotics[1,8]	ILD–rheumatology clinic; DLCO/HRCT-based stratification; advanced therapies where available; registry participation and training role

Structured similar to India’s TB/NCD tier-care delivery systems[13,14] and aligned with ILD-India evidence[1,2]

CROSS-CUTTING CONSIDERATIONS IN THE INDIAN CONTEXT

Several cross-cutting issues merit emphasis for India. Progressive pulmonary fibrosis (PPF) definitions are vital, but spirometry and symptom-based assessments may be the most pragmatic tools for many centres. Monitoring strategies should prioritize spirometry and oximetry, with HRCT and DLCO reserved for referral hospitals or predefined progression checkpoints. Supportive care including vaccination, pulmonary rehabilitation, and oxygen therapy remains underutilized and benefits from more consistent incorporation into routine workflows. Infection safeguards, especially screening for TB and HBV before initiating immunosuppression, are essential in the Indian context. Variation in access to investigations and therapies across centres further underscores the need for shared decision-making and transparent communication with patients regarding available options.[15,16,17,18,19]

CONCLUSION

India stands at a pivotal point in shaping equitable and scalable CTD-ILD care. Beyond adapting global recommendations, the path forward requires structured implementation approaches informed by Indian evidence, resource realities, and health-system strengths.[1] Priority actions include strengthening referral pathways for CTD-ILD, defining a practical minimal diagnostic bundle suitable for district and medical-college settings, and piloting collaborative ILD–rheumatology clinics and structured tele-MDTs across regions. Integrating CTD-ILD metrics into national registries and developing focused training modules for early recognition and steroid stewardship will further support consistent practice across centres.

With coordinated professional leadership, pragmatic tier-based deployment, and academic–policy partnership, India can achieve earlier diagnosis, standardized care pathways, and improved outcomes, while contributing scalable models that inform global CTD-ILD practice.

India’s CTD-ILD journey now calls for implementation science rather than imitation, building solutions here that can guide care everywhere.