Patent ID: 7455980

Claim:
A method to determine the presence, absence or onset of an autoimmune disease within a patient, comprising: exposing a first sample of biological fluid from the patient to a pooled population of particles, wherein a first subset of particles of the pooled population are distinguishable from a second subset of particles of the pooled population based at least on fluorescence characteristics of the particles and at least two different reactants respectively bound thereto, wherein the first subset of particles is bound to a reactant that binds to an autoantibody, and wherein the second subset of particles is bound to a reactant that binds to a self-antigen; measuring an amount of the autoantibody in the first sample of biological fluid; measuring an amount of the self-antigen in the first sample of biological fluid; determining a ratio of the measured amount of autoantibody to the measured amount of self-antigen; and comparing the ratio to one or more standard ratios representing differing states of the autoimmune disease to determine the presence, absence, or onset of the autoimmune disease within the patient.