Background:  Solid organ transplant patients are at an increased risk of developing lip malignancies. The role of HLA mismatch as a risk factor for such changes has only been described in skin.

Methods:  Lip lesions were evaluated in 403 solid organ transplant patients (immunosuppressed for at least 3 months) and findings compared to age and sex matched, otherwise healthy patients who acted as controls. HLA typing was provided for the transplant patients. All patients provided details of smoking history, alcohol consumption, skin type, as assessed by ease of burning to sunlight, and exposure to sunlight or other forms of ultraviolet radiation.

Results:  Lip lesions were identified in 36 transplant patients and 29 were biopsied. Fourteen of the biopsies confirmed dysplastic or malignant changes. For the control patients, one lesion was identified as dysplastic. The prevalence of dysplastic and malignant lip lesions was significantly higher (P = 0.006) in the transplant patients when compared to controls. Risk factors for dysplastic/malignant changes in the transplant group included age (P = 0.01), smoking (P = 0.033) and HLA-B mismatch (P = 0.001). Lip covering provided a significant reduction (P = 0.045) in the development of lip changes.

Conclusion:  All transplant patients should be regularly screened for lip malignancies and consulted on smoking and sunlight exposure. HLA-B mismatch does appear to make these patients more susceptible to dysplastic/malignant changes