Rapid diagnosis of major variants of congenital epidermolysis bullosa using a monoclonal antibody against collagen type IV.

A simple and rapid procedure to diagnose major variants of congenital epidermolysis bullosa (EB) by means of immunohistochemical staining of collagen IV (CIV) in formalin-fixed and paraffin-embedded samples is described. Sixteen cases were stained with a monoclonal antibody (clone CIV 22) against collagen IV present in the lamina densa layer of the basement membrane. Electron microscopy was performed simultaneously. Twelve cases showed one of two staining patterns: an EB simplex pattern (seven cases) consisting of linear and continuous staining on the "floor" of the blister and an EB dystrophica pattern (five cases) showing a linear and discontinuous staining on the "roof" of the blister. In four cases, collagen IV staining was not reactive because of irreversible antigen loss due to inadequate fixation and/or embedding. In those cases with positive staining, an excellent correlation with electron microscopic diagnosis was achieved. This procedure allows a rapid diagnosis of major EB variants, especially where electron microscopy is not available, and also facilitates diagnosis by optimally orienting specimens for ultrastructural examination when available.