Patent ID: 7390631

Claim:
A method for diagnosing systemic lupus erythematosus in an individual, comprising: (a) detecting, in a blood sample from the individual containing red blood cells, quantities of complement component C4d and complement receptor CR1 both of which are on surfaces of red blood cells in the sample, (b) comparing said quantities with, respectively, the quantities of component C4d and receptor CR1 both on surfaces of red blood cells in samples from individuals not having systemic lupus erythematosus, and (c) diagnosing systemic lupus erythematosus in the individual by observing a significantly increased quantity in complement component C4d on surfaces of red blood cells and a significantly decreased quantity of receptor CR1 on surfaces of red blood cells in said sample from the individual compared to said samples from said individuals not having systemic lupus erythematosus.