Pharmaceutical Science: Research Trends and Challenges Vol. 2

Pemphigus vulgaris is a rare autoantibody-mediated blistering disease in which the oral mucosa is usually the first and the most persistent site of involvement. Susceptibility is strongly influenced by inherited variation, most conspicuously within the human leucocyte antigen class II region, and a second tier of non-antigen-presenting loci that act on keratinocyte survival, immune checkpoint signalling and antibody production. The therapeutic landscape has been reshaped by anti-CD20 B-cell depletion, which now holds first-line status for moderate to severe disease, yet a substantial minority of patients relapse early, fail to achieve corticosteroid-free remission, or require repeated cycles. This review examines whether the accumulated genetic and immunogenetic evidence supports a move from population-level association towards individual-level prediction of oral disease expression and of response to rituximab. Literature was identified through structured searching of general and biomedical scholarly indexes, supplemented by citation tracking of trials, consensus documents and prior reviews, and appraised for design adequacy, sample size, ancestral representation, replication and outcome definition. The synthesis indicates that class II associations are robust and mechanistically coherent at the level of peptide-binding chemistry, but that allele frequencies, protective effects and haplotypic context vary sufficiently between populations to limit transportability of any single risk model. Non-antigen-presenting loci show smaller and less consistently replicated effects, with the strongest functional evidence attaching to a promoter variant that raises epidermal expression of a pro-apoptotic transcription factor. Prediction of rituximab outcome currently rests on immunological rather than germline markers, principally residual desmoglein-specific autoantibody, autoantibody subclass diversity, the depth and duration of B-cell depletion and lymphocyte subset dynamics; pharmacogenetic candidates, notably Fc gamma receptor polymorphism, remain unvalidated in this disease. Oral-specific outcome measurement is heterogeneous, which weakens the link between genotype and the phenotype that matters most to patients. Ancestrally diverse, prospectively phenotyped cohorts with harmonised oral scoring are the principal requirement for progress.