Systemic lupus erythematosus

1 . A method for identifying a mammal having severe systemic lupus erythematosus, said method comprising (a) determining whether or not a mammal contains cells having an IFN signature 1, and (b) classifying said mammal as having severe systemic lupus erythematosus if said mammal contains said cells and classifying said mammal as not having severe systemic lupus erythematosus if said mammal does not contain said cells. 
     
     
         2 . The method of  claim 1 , wherein said mammal is a human. 
     
     
         3 . The method of  claim 1 , wherein said cells are peripheral blood mononuclear cells. 
     
     
         4 . A method for assessing systemic lupus erythematosus disease activity, said method comprising (a) determining whether or not a mammal contains cells having an activity signature 1, an activity signature 2, or an activity signature 3, and (b) classifying said mammal as having active systemic lupus erythematosus disease if said mammal contains said cells and classifying said mammal as not having active systemic lupus erythematosus disease if said mammal does not contain said cells. 
     
     
         5 . The method of  claim 4 , wherein said mammal is a human. 
     
     
         6 . The method of  claim 4 , wherein said cells are peripheral blood mononuclear cells. 
     
     
         7 . The method of  claim 4 , wherein said method comprises determining whether or not said mammal contains cells having said activity signature 1. 
     
     
         8 . The method of  claim 4 , wherein said method comprises determining whether or not said mammal contains cells having said activity signature 2. 
     
     
         9 . The method of  claim 4 , wherein said method comprises determining whether or not said mammal contains cells having said activity signature 3. 
     
     
         10 . A method for identifying a mammal likely to experience active systemic lupus erythematosus disease, said method comprising (a) determining whether or not a mammal having systemic lupus erythematosus disease contains cells having an activity signature 3, and (b) classifying said mammal as being likely to experience said active systemic lupus erythematosus disease if said mammal contains said cells and classifying said mammal as not being likely to experience said active systemic lupus erythematosus disease if said mammal does not contain said cells. 
     
     
         11 . The method of  claim 10 , wherein said mammal is a human. 
     
     
         12 . The method of  claim 10 , wherein said cells are peripheral blood mononuclear cells. 
     
     
         13 . A method for identifying a mammal likely to respond to an anti-IFN treatment for systemic lupus erythematosus, said method comprising (a) determining whether or not a mammal having systemic lupus erythematosus disease contains cells having an IFN signature 1, and (b) classifying said mammal as being likely to respond to said anti-IFN treatment if said mammal contains said cells and classifying said mammal as not being likely to respond to said anti-IFN treatment if said mammal does not contain said cells. 
     
     
         14 . The method of  claim 13 , wherein said mammal is a human. 
     
     
         15 . The method of  claim 13 , wherein said cells are peripheral blood mononuclear cells.