Methods for optimizing clinical responsiveness to methotrexate therapy using metabolite profiling and pharmacogenetics

A method for determining clinical responsiveness to methotrexate (MTX) therapy in an individual receiving MTX, wherein said individual has an autoimmune disease, said method comprising:

• determining the concentration level of MTXPG3 in a red blood cell sample from said individual, wherein a concentration level of said MTXPG3 greater than about 60 nmol/L is indicative of superior clinical responsiveness to said MTX therapy.

A method for determining clinical responsiveness to methotrexate (MTX) therapy in an individual receiving MTX, wherein said individual has an autoimmune disease, said method comprising:

• determining the concentration level of MTXPG3 in a red blood cell sample from said individual, wherein a concentration level of said MTXPG3 less than about 40 nmol/L is indicative of inferior clinical responsiveness to said MTX therapy.

A method for optimizing therapeutic efficacy of methotrexate (MTX) therapy in an individual receiving MTX, wherein said individual has an autoimmune disease, said method comprising:

• determining the concentration level of MTXPG3-5 in a red blood cell sample from said individual, wherein a concentration level of said MTXPG3-5 less than about 90 nmol/L is indicative of a need to optimize said MTX therapy.

A method for determining clinical responsiveness to methotrexate (MTX) therapy in an individual receiving MTX, wherein said individual has an autoimmune disease, said method comprising:

• determining the concentration level of MTXPG3-5 in a red blood cell sample from said individual, wherein a concentration level of said MTXPG3-5 greater than about 90 nmol/L is indicative of clinical responsiveness to said MTX therapy.

A method for determining clinical responsiveness to methotrexate (MTX) therapy in an individual receiving MTX, wherein said individual has an autoimmune disease, said method comprising:

• determining the concentration level of MTXPG3-5 in a red blood cell sample from said individual, wherein a concentration level of said MTXPG3-5 less than about 55 nmol/L is indicative of inferior clinical responsiveness to said MTX therapy.