Background/Purpose Autoimmune disorders tend to be aggregated since genetic, epigenetic and environmental pathogenic factors are usually common for several diseases. Specifically celiac disease (CD) is an uncommon comorbidity of Systemic Lupus Erythematosus (SLE), but seems to be extremely underdiagnosed.

We aimed to describe the SLE disease evolution after the CD diagnosis and the gluten free diet (GFD).

Methods An observational ambispective study including patients with prior diagnosis of SLE and posterior diagnosis of CD was performed. The moment since GFD was started was registered. Clinical characteristics of SLE were categorized like in RELESSER study. The first manifestation was considered only if counts in SLEDAI index.

Results 7 patients were included (all women) with a mean age of 45.14 (11.43) years old. SLE had a median evolution of 15 (2.25, 87) months. First manifestation of the disease was reported 48 (24, 84) months before. Domains mainly affected are mucocutaneous, hematological, articular and gastrointestinal. Six patients had history of recurrent aphtosis, which improved in all cases. Only 2 patients had positivity to anti-transglutaminase (IgA) antibodies. Six patients were DQ2 positive.

After being diagnosed of CD and starting the GFD, SLE patients seem to improve especially the leukopenia, lymphopenia and oral aphtosis, as well as SLEDAI score (showed in attached graphics).

Conclusions SLE patients with CD diagnosis and who started a GFD, showed improvement of leukopenia, lymphopenia, oral aphtosis and even SLEDAI.

In SLE patients with recurrent oral aphtosis and/or gastrointestinal unspecific symptoms, CD should be considered, but since serological screening displays a low sensitivity, HLA testing could be helpful. Gastroscopy should be considered, with biopsy and flow cytometer in uncertain cases. Even though, further studies, especially looking for different clinical profiles and longer observational period are needed.