Abstract
Purpose: :
To determine the clinical, immunological and genetic features in a patient with Blau syndrome
Methods: :
A 3 years and 6 months old girl with psychomotor retardation was studied. A probable clinical diagnosis of Blau syndrome was made characterized by dermal lesions (plaques, hives, flaking), joint enlargement, band keratopathy and panuveitis. The methods included determination by flow cytometry of CD3, CD4, CD8, CD19, CD56, TLR2, TLR4, CCR4, CCR7 and CCR9. ELISA was used for detection of IL-1, IL-2, IL-6 and TNF-Alfa in serum, vitreous and aqueous humor. The genetic analysis included PCR amplification of the 12 exons of NOD2 gene from genomic DNA and florescent-labeled terminator sequencing.
Results: :
The immunophenotype characterization showed a decreased in CD3+, CD4+ and CD8+ circulating subsets with conserved relation between CD4:CD8. It also showed an increased CD19+ lymphocyte percentage with no alteration in the frequency of NK cells. The expression of TLR2 and TLR4 was higher in CD3+ cells than in CD3- cells. The CD8+ T lymphocytes were mainly CCR7-; while CD4+ T lymphocytes were CCR4+ and CCR7+. The ELISA analysis showed great IL-6 and IL-2 production in vitreous and IL-2 was also found in great concentration in serum. The genetic analysis showed a punctual mutation from thymine to guanine in M513R nucleotide (4th exon) which predicts a M513R change in the protein NOD dominion. A 100 alleles were analyzed as controls and none of them showed this mutation.
Conclusions: :
The functional immunophenotype characterization suggest that both T lymphocytes CD8+CCR7- and T lymphocytes CD4+CCR4+ could be directly involved in the process of joint damage as has been demonstrated in idiopathic juvenile arthritis for T lymphocytes CD8+ and for T lymphocytes CD4+ in the case of juvenile rheumatoid arthritis. On the other hand, the finding of IL-6 and IL-2 in vitreous could explain the ocular clinical features observed, since IL-6 is a proinflammatory cytokine and IL-2 is the main cytokine related to cellular activation. The genetic analysis showed a new NOD2 mutation. This is the first immuno-genetic analysis of Blau syndrome in Mexico.
Keywords: genetics • immunomodulation/immunoregulation • inflammation