I've had a blood test called cold agglutinins. Doctor is querying raynauds. What else could the doctor be looking for when asking for this test?

Several. Glad you asked. Cold agglutinins damage red cells in the cold and may be elevated for unknown reasons in mycoplasma pneumonia, and also define the uncommon cold agglutinin hemolytic anemias. Cryoglobulins are antibodies that precipitate themselves in the cold; you may also be checked for these; the underlying disease associates are different. Be proactive and read up if the results are positive.