Immunophenotyping in peripheral blood mononuclear cells, aqueous humour and vitreous in a Blau syndrome patient caused by a novel NOD2 mutation.

The genetic and immunophenotypic characteristics of a 3-year-old patient with Blau syndrome (BS), an early onset sarcoidosis caused by mutations in NOD2, were investigated. Molecular analysis of NOD2 gene was achieved by PCR and direct nucleotide sequencing. Immunophenotyping included cytometric analysis of memory-effector markers on T-cells, and cytokine in serum, aqueous humour and vitreous. A novel M513R mutation in NOD2 was demonstrated. Immunophenotyping revealed higher frequency of CCR4+ cells and CCR9+ cells on CD4+ cells; most CD8+ cells were CCR7- and CCR9+. IL6 and IL-8 were detected in a gradient manner: vitreous humour>aqueous humour>serum. The immunophenotype in this patient was characterized by a differential expression of chemokine receptors on T cells and by a particular ocular microenvironment enriched in IL-6 and IL-8. To our knowledge, this is the first study analysing the immunological features of BS at aqueous humour, vitreous and blood levels. Our results expand the knowledge of the genetic and immunopathological basis of BS.