Background: There are few studies ¹ on the treatment of diffuse interstitial lung disease (ILD) associated with systemic lupus erythematosus (SLE). Corticosteroids are usually used in cases of mild to moderate decrease in diffusion and the association with immunosuppressants (Cyclophosphamide, Rituximab…) is reserved for cases of more severe affectation.

Objectives: Assess the main treatments used in ILD associated with SLE in a third level hospital and analyze the therapeutic response through improvement in imaging tests and in respiratory function studies.

Methods: Descriptive observational study of patients diagnosed with SLE (SLICC criteria) who developed ILD in our hospital between 1973 and 2020. As variables of response to treatment, HRCT pattern at diagnosis and at two years, respiratory function tests at diagnosis and at one year were analyzed. Likewise, the different treatments used before and after diagnosis were studied such as hydroxychloroquine (HCQ), prednisone, methotrexate (MTX), Rituximab (RTX), belimumab (BLM), Cyclophosphamide (CFM), azathioprine (AZA) and mycophenolate mofetil (MMF).

Results: A total of 455 patients diagnosed with SLE were included, of which 20 had ILD (4.4%). 65% of the analyzed sample were women with a mean age at diagnosis of 63 ± 16.23 years. 30% presented ILD as the first clinical data for the diagnosis of SLE. Only 3 patients died (due to causes other than ILD and SLE). At diagnosis, 90% had symptoms such as dyspnea (75%) and cough (60%).

85% had alterations in the X-ray and 100% in the HRCT, where the predominant pattern was NINE (65%). Spirometry showed an obstructive (25%), restrictive (20%) and normal (55%) pattern; 90% had decreased diffusion, the majority being mild (67%). With the treatment administered, HRCT stability was observed at two years in 30% of cases and progression in 25%; while, at the functional level, 40% remained stable with worsening in 4 patients per year (20%).

50% of the patients with SLE received treatment with HCQ and MTX before the diagnosis of ILD; and 35% corticosteroids (4 + 7.3 mg / day). With ILD diagnosed, HCQ was administered to 95% of patients and the standard of treatment was based on corticosteroids in monotherapy at a mean dose of 13 ± 10.5 mg / day due to stability both at radiological level and in function tests respiratory. 25% and 15% required treatments such as RTX and BLM as they did not have an adequate response with the previous one.

In our study, we did not find any statistical significance between the variables analyzed, due to the small sample size.

Conclusion: 1)ILD in SLE is a rare manifestation, present in 4.4% of our series. Standard treatment with hydroxychloroquine and corticosteroids appears to be a useful therapeutic option, stabilizing radiological progression in one third of cases early. More studies with a larger sample size are needed to analyze the role of immunosuppressive treatment in this type of lung involvement.

REFERENCES:

[1]Aguilera-Pickens G, Abud-Mendoza C. Pulmonary Manifestations in Systemic Lupus Erythematosus: Pleural Involvement, Acute Pneumonitis, Chronic Interstitial Lung Disease and Diffuse Alveolar Hemorrhage. Clinical rheumatology. Vol.14 Issue. 5. Pages 294-300 (September-October 2018).

Disclosure of Interests: None declared