Category: Immune monitoring
Aims: Cutaneous T-cell lymphomas (CTCL) are a group of lymphomas comprising Mycosis Fungoides (MF) and Sézary syndrome (SS) which is characterized by erythroderma and high numbers of atypical lymphocytes. A blood classification was added to TNM staging and flow cytometry (FCM) became a promising method. We have shown the reliability of KIR3DL2 as a positive marker for SCs. We report our 4 years expertise for initial diagnosis in 219 patients.
Methods: CD7, CD26, and KIR3DL2 labelling was performed. Patients were diagnosed according to the ISCL/EORTC classification for CTCL. We gathered the samples at diagnosis for 31 SS, 5 pre-SS, 45 MF, 12 EMF and 126 patients with inflammatory skin diseases (ISD). 2 groups of patients were defined, according to their CD4+T-cell absolute counts: group A (≥1000/mm3) and group B (<1000/mm3).
Results: A strong positive correlation between KIR3DL2+ and CD4+CD26-T-cell count was found in group A (r=.81, p<.0001). A value of KIR3DL2+T-cells ≥200/mm3 allowed a specificity of 90% and a sensitivity of 86% for SS diagnosis. In group B, all patients with KIR3DL2+ T-cells ≥200/mm3 were SS. Five patients initially diagnosed as MF or pre-SS developed SS within 2-7 months. These patients already displayed >200/mm3 KIR3DL2+ at initial time point.
Conclusion: the detection of KIR3DL2+T-cells improves the biological diagnosis of SS. A threshold value of KIR3DL2+ cells ≥200/mm3 in MF and pre-SS patients with CD4 lymphopenia may be predictive for SS evolution. We therefore recommend to use this marker for the initial diagnosis and staging of CTCL, in association with CD26.
Marie Rolens– INSERM 1160
Adèle de Masson– Dermatology department
Caroline Ram-Wolff– Dermatology department
Anne Marie-Cardine– INSERM 976
Armand Bensussan– INSERM 976
Antoine Toubert– INSERM 1160
Martine Bagot– Dermatology department
Hélène Moins-Teisserenc– INSERM 1160