Desmoplakin is the target antigen in:
Pemphigus vulgaris
Drug induced pemphigus
Paraneoplastic pemphigus
Pemphigus foliaceous
Paraneoplastic pemphigus is a severe variant of pemphigus, associated with an underlying neoplasm - most frequently non hodgkin's lymphoma, chronic lymphocytic leukemia, thymoma, and castleman  disease. Tumor antigens are hypothesized to evoke an immune response that leads to the development of an autoimmune response to intercellular adhesins (plakins). This autoantibody response leads to blistering in mucosa and other epithelia.
Ref: Neville's oral and maxillofacial pathology 4th edition page 717-718