CD4 and toxic epidermal necrolysis: In 15 patients with SJS/TEN, the LPA alone had a sensitivity of only 27%, whilst a combined approach evaluating granulysin expression in CD4+ T-cells, together with a granzyme B enzyme-linked immunosorbent spot (ELIspot) and IFNγ production, provided a sensitivity of 80% and specificity of 95% [63].