ESPE Abstracts

Background: APS type 1 is known to be associated with autoimmune gastroenterological pathology, which could be the very first and the worst-controlled manifestation of APS type 1. Treating these conditions in APS type 1 is debatable at present.

Objective and hypotheses: We describe gastroenterological pathology in7 patients with APS type 1: clinical specifics, therapy, outcomes.

Methods: 7 patients (male, n=6, female, n=1) with APS type 1 were treated in the gastroenterology department of our clinic in 2013-2022. In 6 cases, the diagnosis of APS type 1 is confirmed molecular genetically, in 1 case antibodies to interferon ɷ were detected. In AIH patients, LKM-1 and SMA antibodies were controlled.

Results: AIH was diagnosed in 6 patients. The mean age of onset is 3 years 11 months. In 3 patients AIH was the first identified manifestation of APS1. At diagnosis, hepatitis activity ranged from minimal to high, outcomes vary from absence of fibrosis to cirrhosis (from F0 to F4 METAVIR). LKM-1 AB detected in 1 case, SMA was not detected. 4 children received prednisolone + azathioprine combination with an outcome in stable remission, 1 child received immunosuppression simultaneously for AIE and AIH, a combination of Prednisone with Tacrolimus was chosen, stable remission for hepatitis achieved, in one case immunosuppression is not needed today. Malabsorbtion was performed in 4 patients, requiring immunosuppressive therapy in 2 patients. Combination of Prednisone with Tacrolimus was performed in one case with complete response, in the second case Prednisone whith Azathioprine combination provided a partial response. In 2 patients, severe B12 deficiency was detected. In one case, it led to severe anemia and leukopenia, GPA positive, biopsy showed atrophic gastritis. The second patient hasn’t undergo examination yet. 5 patients were found to have a homozygous mutation R257X in the AIRE gene, 1 patient had a heterozygous mutation R257X/C434X, AIRE sequencing was not performed in one child, R257X mutation was not detected by PCR (ethnic Tajik).

Conclusions: in our group, hepatitis characterized by an early onset and atypical course (absence of typical antibodies for AIH 1 and 2, nonspecific biopsy pattern), high sensitivity to standard immunosuppressive therapy. Enteropathy characterized by an undulating course, high infusion dependence in exacerbations. In one case combination of corticosteroids with tacrolimus was used successfully. Immune atrophic gastritis is rare in childhood; in our department it was noted only in APS 1. We didn’t find out the genotype specifics in our group.