I had a blood test called "candida albicans ag response". the result was zero and it was flagged as "low". what does that mean?

No antigen: A titer of less than 2 indicates that circulating Candida antigen is not present or that Candida species are present as a commensal only. A negative reaction does not exclude the possibility of systemic Candida infection, because in immunocompetent patients the antigen may be present as part of an immuno-complex which does not react in this test system.