Table 4. LTT/ELISpot assay.

Advantages	Disadvantages
The ELISpot in particular can help to identify the trigger of severe bullous drug reactions in which other test procedures are either not helpful or obsolete	Lack of standardization
This test method yields positive results even years after the event	Technically complex, expensive, and time-consuming
	Requires a large volume of fresh blood
A test method that poses no hazard to the patient	The evidence is insufficient
ELISpot enzyme linked immunosorbent spot assay, LTT lymphocyte transformation test