Serodiagnosis of Lyme borreliosis—is IgM in serum more harmful than helpful?

Table 3 Criteria for estimating the likelihood and accuracy of the potential diagnosis of Lyme borreliosis (LB) made by the clinician [1, 2, 4]

LB diagnosis	Objective clinical signs consistent with LB (Table 1)	Serology supporting the suspected manifestation (Table 1)	Seroconversion or significant elevation of antibodies^a
Confident	Yes	Yes	Yes
Doubtful	Yes	No	No
Doubtful	No	Yes	No
Unlikely	No	No	No

^aThese parameters were assessed when available. Seroconversion, from negative to positive (IgM or IgG). Significant elevation of antibodies, a 2-fold increase or more of the antibody level (optical density)