Clinical and immunological aspects of HLA class I deficiency.

摘要: Human leukocyte antigen (HLA) class I deficiency is a rare disease with remarkable clinical and biological heterogeneity. The spectrum of possible manifestations extends from the complete absence symptoms to life-threatening conditions. It usually diagnosed when HLA serological typing unsuccessful; flow cytometric studies then reveal severe reduction in cell surface expression molecules (90-99% compared normal cells). In most cases date, this low due homozygous inactivating mutation one two subunits transporter associated processing (TAP), critically involved peptide loading molecules. Although asymptomatic have been described, TAP deficiencies are characterized by chronic bacterial infections upper lower airways, evolving bronchiectasis, half cases, also skin ulcers features granulomatous inflammation. Despite defect class-I-mediated presentation viral antigens cytotoxic T cells, patients do not suffer infections, presumably because other efficient antiviral defence mechanisms such as antibodies, non-HLA-class-I-restricted effector cells CD8+ T-cell responses TAP-independent antigens. Treatment at present exclusively symptomatic, should particularly focus on prevention which requires early detection.