Abstract
Objective: To assess the pattern of organ involvement and the antibodies which are tested positive in patients of Mixed Connective Tissue Disease (MCTD) with Interstitial Lung Disease (ILD) at Lahore Pakistan.
Methods: The present descriptive retrospective study included medical records of MCTD patients with ILD from January 2022 to December 2024. Patients of both sex, aged 21 to 80 years, fulfilling the Alarcón-Segovia diagnostic criteria of MCTD were included. Patients with incomplete diagnostic criteria data or lost to follow-up and with connective tissue diseases other than MCTD such as Systemic Lupus Erythematosus, Systemic Sclerosis and Undifferentiated Connective Tissue Disease were excluded. Details regarding demography, autoantibody positivity, organ systems involved and pattern of ILD on HRCT chest were collected and analyzed.
Results: Mean age of the patients was 47.2±11.6 years with 12 (54.5%) patients aged ≥46 years, and all the 22 patients were female. Non-specific interstitial pneumonia (NSIP) was seen in 17 (77.3%) patients whereas 05 (22.7%) had usual interstitial pneumonia (UIP). ANA was positive in 21 (95.5%) and Anti-DsDNA antibodies in 04 (18.2%). Raynaud’s phenomena was the most common feature seen in 19 (86.4%) patients followed by arthritis in 17 (77.3%), oesophageal dysmotility in 16 (72.7%) and sclerodactyly in 13 (59.1%). Renal involvement was not seen in any patient.
Conclusion: MCTD with ILD was seen in young females. ANA positivity, Raynaud’s phenomena, arthritis, oesophageal dysmotility and sclerodactyly were seen frequently in MCTD patients with ILD.

Key words: Mixed Connective Tissue Disease (MCTD), Interstitial Lung Disease (ILD), Autoimmunity, Anti-U1 RNP antibody, Raynaud’s phenomena.