Poster Display Immune dysregulation & autoimmunity

BARE CLASS II SYNDROME. A NEW MUTATION CIITA IS REPORTED IN COLOMBIA.

Lecture Time
10:35 - 10:36
Presenter
  • William R. Marquez, Colombia
Room
Poster Area
Date
19.09.2019, Thursday
Session Time
10:00 - 17:00
Board Number
107
Presentation Topic
Immune dysregulation & autoimmunity

Abstract

Background and Aims

Background:Bare II lymphocyte syndrome is characterized by the absence of expression of HLA class II molecules. It is the result of a mutation in the genes encoding one of the 4 elements that regulate the expression of HLA class II molecules. Patients present recurrent infections characteristic of combined immunodeficiency.

Methods

Methods:
Child is two years old. At 12 months presented protracted diarrhea, enterorrhagia, failure to thrive . He presented multiple pulmonary and gastrointestinal infections and required gastrostomy and parenteral nutrition. At 18 months he presented non-infectious hepatitis. Several months later he had intestinal intussusception that it reduced by manual in a laparoscopy procedure.

Results

Results:
Lung CT scan showed imagen suggestive a lipoid pneumonia or pneumonia by Pneumocystis jirovecii. Intestinal MRI showed thickening of distal ileum, caecum, similar an inflammatory bowel disease (IBD), probable Crohn disease. Gastrointestinal biopsies ruled out BID.Flow cytometry: CD3+ 49. 60%/1858 cel/uL, CD4+: 7. 35%/275 (low), CD8+: 40. 47%/1515 , BCD19+: 44. 58%/153. IgA 0. 0 mg/dL, IgG 49, IgM 110, IgE 0. 10 IU/ml. It was observed total absence of the expression of MHC Class II molecule in T lymphocyte and monocyte in our patient.

We performed the mutation analysis of genes (NGS)encoding CTIIA, RFX5,RFXAP, RFXNK. We report a new mutation in CIITA gene cr16:c. 925C>T in exon 9;p. (Arg309) probably a pathogenic variantnot yet reported in the literature.

Conclusions

Conclusion:
Bare class II lymphocyte syndrome went confirmed by absence of the expression of MHC Class II molecule in T lymphocytes and Monocytes in our patient and the identified new mutation in CIITA.

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