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 A functional division of T- cells can be based on the cytokines they produce: 
  
TH1 type 
| • | interferon gamma and IL-2 |  
 | • | augment cell-mediated immune response by activating macrophages (e.g. delayed type hypersensitivity reactions) |  
   
TH2 type 
| • | augment humoral response, and inhibit some cell mediated response |  
 | • | IL-4 --> hypergammaglobulinemia;  switch in the antibody isotype from IgM to IgE |  
 | • | IL-10 --> reduction in cell mediated immunity |  
   
  
diseases: 
  
Psoriasis --> (CLA+) CD8 T-cells with Th 1 cytokines Th2 in the early phases;  Th1 in the late and chronic phases 
Allergic contact dermatitis --> (CLA+) CD8 T-cells with variable cytokine profile (both Th1 and Th2 cytokines) 
Atopic dermatitis --> (CLA+) CD4 T-cells with Th2 cytokines  
Mycosis Fungoides --> a tumor of (CLA+) CD4 T-cells 
  
CTCL: 
| • | both resting and stimulated cells from the blood of patients with leukemic CTCL make cytokines of the Th2 type |  
 | • | the most commonly encountered malignant cutaneous T-cell is a Th2 CD45RO+ CLA+ T-cell |  
   
eosinophilic folliculitis: 
| • | preliminary evidence from both peripheral blood and skin of patients with eosinophilic folliculitis show the lymphocytes are making IL-4 and IL-5 but are not making gamma interferon or IL-2 |  
   
Leishmaniasis: 
| • | Th2 – disseminated infection  (therefore some treat with interferon gamma and antimony) |  
   
Leprosy: 
| • | tuberculoid leprosy - Th2 |  
 | • | lepromatous leprosy - Th1 |  
   
  
  
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