P234 Association between anti-TNFα drug levels and drug-induced lupus in patients with Inflammatory Bowel Disease

Muñoz-Villafranca, C.(1);Irabien, M.(1);Hernandez-Aretxabaleta, N.(1);Arreba, P.(1);Ortiz de Zárate, J.(1);Garcia-Gomez, C.(2);Aresti, U.(3);Bilbao, A.(3);Irigoyen, M.(4);Garcia-Vivar, M.L.(2);

(1)Hospital Universitario Basurto, Gastroenterology, Bilbao, Spain;(2)Hospital Universitario Basurto, Rheumatology, Bilbao, Spain;(3)Hospital Universitario Basurto, Research, Bilbao, Spain;(4)Hospital Universitario Príncipe de Asturias, Internal Medicine, Madrid, Spain; Gastro-Reuma

Background

Drug-induced lupus (DIL) has been described as an adverse event of an immunological nature, in relation to treatment with anti-TNFα drugs. It is considered as a manifestation uncommon in patients with inflammatory bowel disease (IBD).

The main objective of the study was to know the prevalence of DIL, the main characteristics and the management of IBD patients. The secondary objetive was to identify predictive factors related to the pathology.  

Methods

We conducted a retrospective study, between January 2017- March 2020, in patients with IBD treated with anti-TNFα drugs during this time, in a single center. The information was obtained from the clinical history of the hospital. Patients with different degrees of data incompleteness were dismissed.

Although there are no accepted diagnostic criteria, diagnosis was based on the criteria proposed by De Bandt: (i) the presence of immunologic abnormalities: ANA+ and/or anti-dsDNA+; (ii) at least two clinical features; (iii) clear temporal association with exposure to the anti-TNFα.

The serum concentration of Infliximab (IFX) was considered optimal within the interval 3–7 μg/mL2. For Adalimumab (ADA) the optimal interval was 5-8 μg/mL3.

Results

We identified 248 patients with anti-TNFα therapy. 15 of them were dismissed due to incomplete data.

We found 8 patients with a DIL diagnosis (3.34%). The manifestations of DIL occurred after a mean of treatment duration of 29.63 months. The clinical features of DIL included arthritis (87.5%), fatigue (75%), fever (25%), vasculitis, cutaneous manifestations, and nephropaty (12.5%) each. All patients required specific treatment and in 7 of them (87.5%) the anti-TNFα drug was discontinued followed by complete clinical resolution in all of them.  

Patients with DIL had a higher prevalence of suboptimal serum concentration of anti-TNFα drug than the rest of the patients (83.33% versus 29.89%, p = 0.012). In addition, the combination therapy with immunomodulators (IMM) was less frequent in the DIL group (0% versus 64.37%, p = 0.003). Antinuclear antibodies (ANA) had a higher prevalence in DIL cases (100% versus 25.36%, p>0.001).

No differences were found regarding the type of disease (CD versus UC), duration of anti-TNFα treatment, previous treatment with another anti-TNFα or with the type of anti-TNFα (IFX versus ADA).

Conclusion

The prevalence of DIL in IBD patients undergoing anti-TNFα treatment could be even higher than described due to the lack of knowledge of the disease and the absence of clearly reported diagnostic criteria. The DIL does not seem to be related to the type of disease, or the type of anti-TNFα. Suboptimal serum concentrations of anti-TNFα, as well as monotherapy treatment (without IMM) could be related to the development of DIL.