Mucous membrane pemphigoid: recent advances

Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is a clinically and immunopathologically heterogenous disease with an incidence of about 2/million inhabitants/year in central Europe. Pemphigoid diseases are characterized by autoantibodies against structural proteins of the epidermis and/or surface-close epithelia. MMP has been defined as pemphigoid disease with predominant mucosal lesions. Most frequently, the oral cavity and the conjunctivae are affected. Lesions outside the mouth tend to heal with scarring leading to visual impairment and finally blindness, as well as, more rarely, impairment of breathing and food intake. Autoantibodies target BP180 (collagen type XVII), laminin 332, BP230 (nearly always in conjunction with other antigens), and type VII collagen in about 75%, 10-20%, 10-30%, and <5% of MMP patients, respectively. While the main autoantibody isotype is IgG, additional, and less frequently, exclusive IgA autoantibodies can be detected in the majority of patients. Assaying for anti-laminin 332 reactivity is pivotal, since in about a quarter of patients with anti-laminin 332 MMP, a malignancy, mainly solid cancers, is associated. The pathophysiology of MMP is yet incompletely understood. A recent mouse model of anti-laminin 332 MMP replicating characteristic clinical and immunopathological findings of the human disease may be helpful to close this knowledge gap. Diagnosis is established by the clinical picture with predominant mucosal lesions and visualization of tissue-bound anti-basement membrane zone antibodies by direct immunofluorescence microscopy. In recent S3 guidelines initiated by the European Academy of Dermatology and Venereology, the clinical spectrum and diagnostic strategies are detailed. In addition, treatment regimens for different clinical situations including patients with exclusive oral or ocular involvement are outlined. Future studies are needed to better understand the clinal complexity and associations as well as to establish widely available diagnostic assays and evidence-based therapeutic strategies.

Characterization of Progressive Cicatrizing Conjunctivitis With Negative Immunofluorescence Staining

PURPOSE

To characterize the clinical features of patients with direct immunofluorescence (DIF)-negative mucous membrane pemphigoid (MMP).

DESIGN

Retrospective case series.

METHODS

Thirty-six patients who underwent a conjunctival biopsy for suspected MMP were included. Demographic and clinical information was collected. Main outcome measures included visual acuity, Foster stages, presence of extraocular involvement, history of autoimmune disease, and durations of follow-up.

RESULTS

Thirty-two patients had a negative DIF. Of those, 2 had a positive DIF on repeat biopsy. Eleven showed progression of conjunctival scarring during a median follow-up of 42 months (range, 8-100 months) and were diagnosed with biopsy-negative MMP. Another 11 patients with a median follow-up of 54 months (range, 15-138 months) were diagnosed with cicatrizing conjunctivitis of other causes. The median visual acuity of patients with biopsy-negative MMP at presentation was significantly lower compared to patients with cicatrizing conjunctivitis of other causes (20/400 vs 20/40, P = .02). Conjunctival scarring score at presentation in both biopsy-positive and biopsy-negative MMP groups was significantly higher compared to patients with cicatrizing conjunctivitis of other causes (median Foster stage, 3 vs 1, P = .009; and 3 vs 1, P = .01, respectively).

CONCLUSIONS

Patients with progressive cicatrizing conjunctivitis likely have MMP in the absence of alternate diagnoses. Our findings emphasize that suspicion for MMP must remain high for patients who have Foster stage 3 conjunctival scarring on presentation or worsening of scarring during follow-up, even in the setting of negative DIF.

Methotrexate as a treatment in ocular cicatricial moderate pemphigoid

CLINICAL CASE

A 73 year-old woman presented with a history of non-specific symptoms and photophobia in both eyes of 1 year progression. The examination revealed a bilateral symblepharon and fornix shortening. Immunohistochemical analysis confirmed the presence of linear deposits of IgG, IgM and C3 along the conjunctival basement membrane. With the diagnosis of Ocular Cicatricial Pemphigoid, systemic treatment with subcutaneous methotrexate was prescribed.

DISCUSSION

We consider such treatment a very effective initial immunosuppressive alternative in patients with moderate conjunctival inflammation and in cases of rapid progression.

Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is chronic and frequently associated with exacerbations and remissions of clinical signs and symptoms. Clinicians should use pathologic and immunonologic techniques to help diagnose patients. Multidisciplinary collaboration is often necessary for the diagnosis and proper treatment of MMP. Systemic adjuvant immunosuppressive therapy is necessary for patients with progressive disease. In spite of the advances in available immunosuppressive medications and biologics, scarring is a significant complication in many cases. Surgical intervention is not curable; however, it may be necessary for restoring function and improving quality of life.