Autoantibodies against Desmoglein 1 and 3 in South Tunisian pemphigus.

BACKGROUND: Desmoglein (Dsg) 1 and 3 are the 2 major autoantigens in pemphigus foliaceus (PF) and pemphigus vulgaris (PV). AIM: We aimed to determine anti-Dsg1 and 3 Abs'usefulness in the diagnosis of pemphigus and to assess the correlation of these antibodies (Abs) with clinical phenotype and disease activity in south Tunisian patients. METHODS: We retrospectively analyzed 131 samples from 82 patients (52 with PF and 30 with PV) during follow-up. Anti-Dsg1 and 3 Abs were measured by ELISA. Consecutive anti-Dsg1 and 3 Abs were correlated with disease activity. Receiver operating characteristics (ROC) curve were calculated to determine anti-Dsg1 and 3 Abs'cut-offs with optimal sensitivity and specificity for disease activity. RESULTS: Anti-Dsg1 and 3 levels were associated to in PF and PV patients respectively (p<0,001). Anti-Dsg1 and 3 Ab were associated with skin (95%) and mucosal (60%) lesions, respectively. A significant decrease of anti-Dsg1 Abs was observed in patients with PF in clinical remission (36 ± 62 U/mL; (p=0,04). No correlation was found between anti-Dsg3 Abs and the course of mucosal lesions in PV (p=0,3). During follow-up, anti-Dsg1 Abs correlated with relapses (177 ±60 U/mL ; p=0,04). The 161,5 U/mL cut-off for anti-Dsg1 Abs provided 100% specificity and 86,4% sensitivity in PF disease activity. The 30,7U/mL cut-off for anti-Dsg3 provided 89,5% sensitivity and 100% specificity in PV. CONCLUSIONS: High anti-Dsg3 Abs values are not always associated with PV disease activity. Anti-Dsg1 Abs showed a closer relationship with skin activity in PS and should be therefore taken into account in management of pemphigus patients.

Pemphigus herpetiformis in South Tunisia: a clinical expression of pemphigus foliaceus?

BACKGROUND: Pemphigus herpetiformis (PH) is a rare subtype of pemphigus combining clinical features of dermatitis herpetiformis and the immunopathologic characteristics of pemphigus. We aimed to analyze the epidemiological, clinical, and immunological presentation and management of the disease in a cohort of south Tunisian patients with a long-term follow-up. METHODS: We included all patients with confirmed PH followed from January 1987 to December 2015 in the dermatology department. RESULTS: We included 24 south Tunisian female patients with a mean age of 36 years (20-63), mainly from rural origin (84%). All patients had exclusive skin lesions. Clinical features combined erythematous, vesicular, or bullous lesions, with circinate borders mainly on the trunk and limbs associated with severe pruritus (91%). Peripheral hypereosinophilia was noted in 31% of cases. Histological examination demonstrated no intraepithelial (50%), suprabasal (35%), or subcorneal cleavage (15%). Eosinophilic spongiosis was seen in 42% of cases. On direct immunofluorescence, there was an intercellular staining in 96% of cases composed mainly of IgG and C3 (79%). Indirect immunofluorescence was positive in 71% of cases. Reactivity was mainly directed against Dsg1. Dapsone alone was inefficient. All patients received systemic corticosteroids. Most patients (64%) relapsed. Iatrogenic complications and cutaneous infections were noted in 40% and 16% of cases, respectively. CONCLUSION: PH is characterized by the occurrence of exclusive skin lesions in young women with a good response to corticosteroids but not to Dapsone. Reactivity mainly against Dsg1 suggests that PH in south Tunisia is a particular variant of nonendemic pemphigus foliaceus.