Sezary Syndrome (SS) is a rare form of Cutaneous T-Cell Lymphoma (CTCL) characterised by a distinct metastatic pattern mainly involving skin and blood. Exact pathogenesis of this disease is at the moment unknown and no characteristic translocation or loss of tumor suppressor has been identified. We have observed and collected samples from 29 patients in the last 8 years and have performed microarray data either for expression and genomic single nucleotide polymorphisms analysis (SNPs). We utilized oligonucleotide microarray to interrogate the expression of 22,215 known genes using the Affymetrix Human Genome U133A Array on RNA of 14 sorted CD4 T-lymphocytes from peripheral blood lymphocytes of healthy individuals either in the resting phase (T-CD4R) or activated (T-CD4A) with a bacterial superantigen (toxic shock syndrome-toxic-1). We compared these RNAs to sorted and clonal RNA samples derived from SS patients (T-CD4S) (> 95% were tumor cells as assed by staining with Vbeta monoclonal antybody). We also allelotyped tumour and autologous normal samples for over 10,000 SNPs in a set of 13 patients. Our preliminary results show that LOH (Loss of Heterozygosity) involve the following chromosomal regions: 9p21.2p21.1(31%), 9q21.2q21.32(31%), 10p12.1p11.21 (38%), 10p11.21q11.21(31%), 10q21.1q21.3(31%), 10q23.1q25.3(46%), 17p13.3-17q11.1(62%). Gains were most frequent at chromosome 17q(54%) and chromosome 8. This latter one results entirely duplicated in 3 out of 13 patients, while smaller common amplifications encompass regions 8q12.3q13.3(46%)and 8q21.3q22.3(46%). The correlation between pattern of consistent losses in genomic areas and the expression profile has been variously investigated either functionally or at informatic level and it is being currently evaluated against clinical-pathological features.

[Proc Amer Assoc Cancer Res, Volume 47, 2006]