Two Cases of Dermatitis Herpetiformis Successfully Treated with Tetracycline and Niacinamide.

Dear Editor, Dermatitis herpetiformis (DH) is a chronic, polymorphic, pruritic autoimmune blistering skin disease characterized by subepidermal blisters, neutrophilic microabscesses, and granular IgA deposition within the dermal papillae. DH is classified as a cutaneous manifestation of coeliac disease, a type of gluten-sensitive enteropathy (1). The treatment of DH includes dapsone and a gluten-free diet (GFD). Other therapies should be considered in patients who are unable to tolerate dapsone, including sulfapyridine and glucocorticoids. Herein we present two cases of DH with good responses to tetracycline and niacinamide combination therapy. Case 1 was a 42-year-old man who was admitted to our hospital with a 3-year history of recurrent pruritic papules and bullous lesions involving the trunk and upper limbs. On examination, the patient showed disseminated erythematous papules on the upper limbs and back as well as vesicles. Nikolsky's sign for vesicles was negative (Figure 1, a-c). The results of routine blood examinations were within normal ranges. He did not have a history of chronic diarrhea. The histologic examination showed subepidermal blisters and accumulation of neutrophils at the papillary dermis of the involved ski. Direct immunofluorescence revealed fibrillar deposition of IgA on the dermal papillae (Figure 1. g, h). Case 2 was a 34-year-old woman who had a history of skin rash and pruritic lesions predominantly involving the arms and legs, which had been present for 10 months. She had been treated with prednisone (30 mg daily) with improvement; however, the lesions reappeared when the prednisone was discontinued. She had a history of constipation. On physical examination, the skin lesions manifested as erythematous papules, vesicles, and scabs on the limbs (Figure 2. a-c). She felt apparently pruritic. The histologic examination of the biopsy identified subepidermal blisters with a neutrophil infiltrate in the upper dermis. Direct immunofluorescence revealed granular deposition of IgA on the dermal papillae (Figure 2. e, f). The results of routine blood examinations were within normal ranges, with the exception of elevated IgE concentration (222.5 ku/L (normal range, 0-100 ku/L)). The clinical manifestations and histologic and immunofluorescence examinations of the two cases confirmed the diagnosis of DH. The two patients were subsequently started on a strict GFD. At that time, dapsone was not available in the hospital. The patients were treated with oral tetracycline (500 mg four times daily) and nicotinamide (500 mg three times daily). The rash affecting case 1 resolved entirely in 2 weeks. The patient discontinued the medications after 6 months, and occasionally presented with a few pruritic papules and vesicles, but the lesions resolved within 1 week. The lesions affecting case 2 completely healed within 1 month. The patient continued taking those medications and no recurrence of the skin lesions occurred during 2 years of follow-up. Dapsone is considered first-line therapy for patients with DH (2). Recent findings have shown dapsone and lower dosages of sulfasalazine combination therapy in DH are effective and well-tolerated (3). Alternative monotherapeutic agents in mild autoimmune bullous diseases such as DH include a tetracycline group of antibiotics with niacinamide or its derivatives as well as sulfasalazine. Because dapsone is difficult to obtain in China except for patients with leprosy, we treated the patients with tetracycline and nicotinamide. To our knowledge, only a few cases of DH have been successfully treated with oral tetracycline and niacinamide (2,4). One of the patients was also prescribed heparin (4). Tetracycline has anti-inflammatory properties due to the inhibition of metalloproteinase activity and mast cell activation (5). Nicotinamide is a potent modulator of several pro-inflammatory cytokines. Nicotinamide can inhibit cytokine release (IL-1, IL-6, IL-8, and TNF-α) from immune cells, inhibit chemotaxis and degranulation of immune cells, inhibit lymphocyte blast transformation, and suppress T-cell activity (6). The non-antibiotic properties of tetracycline in combination with nicotinamide may participate in inhibition of antibody formation, modulation of pro-inflammatory cytokines, inflammatory cell accumulation, lymphocyte transformation, and T-cell activation. In summary, we reported two typical cases of DH that were successfully treated with oral tetracycline and niacinamide, which completely healed the rash and relieved the symptoms within 1 month. The combination of tetracycline and nicotinamide can be recommended as a useful therapy for patients where dapsone is not available or for patients who do not tolerate dapsone.

Discovery of six new susceptibility loci and analysis of pleiotropic effects in leprosy.

Genome-wide association studies (GWAS) have led to the discovery of several susceptibility loci for leprosy with robust evidence, providing biological insight into the role of host genetic factors in mycobacterial infection. However, the identified loci only partially explain disease heritability, and additional genetic risk factors remain to be discovered. We performed a 3-stage GWAS of leprosy in the Chinese population using 8,313 cases and 16,017 controls. Besides confirming all previously published loci, we discovered six new susceptibility loci, and further gene prioritization analysis of these loci implicated BATF3, CCDC88B and CIITA-SOCS1 as new susceptibility genes for leprosy. A systematic evaluation of pleiotropic effects demonstrated a high tendency for leprosy susceptibility loci to show association with autoimmunity and inflammatory diseases. Further analysis suggests that molecular sensing of infection might have a similar pathogenic role across these diseases, whereas immune responses have discordant roles in infectious and inflammatory diseases.

Evaluation of the combination of BP180-NC16a enzyme-linked immunosorbent assay and BP230 enzyme-linked immunosorbent assay in the diagnosis of bullous pemphigoid.

BACKGROUND: Bullous pemphigoid (BP) is an acquired autoimmune subepidermal blistering disease characterized by circulating IgG autoantibodies directed against BP180 and BP230 hemidesmosomal proteins. Previous studies have demonstrated that antibodies against the NC16a domain of BP180 mediate BP pathogenesis, while antibodies against BP230 enhance the inflammatory response. Recently, commercial BP180-NC16a enzyme-linked immunosorbent assay (ELISA) and BP230 ELISA kits were developed to detect anti-BP180 and anti-BP230 autoantibodies in human BP sera. AIMS: To evaluate the efficacy of BP180-NC16a ELISA and BP230 ELISA in the initial diagnosis of BP. METHODS: Sera from 62 BP patients and 62 control subjects were tested by BP180-NC16a ELISA and BP230 ELISA and compared with findings from indirect immunofluorescence (IIF) and immunoblotting (IB) to determine the sensitivity and specificity of these assays. RESULTS: The sensitivities of BP180-NC16a ELISA and BP230 ELISA were 87.1% (54/62) and 56.5% (35/62), respectively, and the specificities of both were 100% (62/62). Using both ELISAs for diagnosis increased the sensitivity to 95.2% (59/62) and was statistically comparable with IB sensitivity. CONCLUSIONS: ELISA is a convenient, effective, and reliable method for serodiagnosis of BP, and combined use of BP180-NC16a ELISA and BP230 ELISA can increase the sensitivity of this diagnostic approach.

Accuracy of indirect immunofluorescence on sodium chloride-split skin in the differential diagnosis of bullous pemphigoid and epidermolysis bullosa acquisita.

BACKGROUND: Previous reports have shown that indirect immunofluorescence (IIF) performed on sodium chloride-split skin (SSS) is helpful to differentiate epidermolysis bullosa acquisita (EBA) from bullous pemphigoid (BP). Antibodies of BP may bind to the epidermal side of SSS, while antibodies of EBA bind to the dermal side. AIMS: To determine the accuracy of IIF-SSS in the differential diagnosis of EBA and BP utilizing immunoblotting (IB) analysis. METHODS: Sera from 78 patients, diagnosed with BP by clinical features, histopathology, and direct immunofluorescence (DIF), were assayed using IIF-SSS and IB. RESULTS: Of the 43 serum samples with an epidermal reaction to IIF-SSS assay, 42 were recognized with BP antigens (180 kDa or 230 kDa). Of the 11 serum samples with a dermal reaction pattern, 7 were recognized with the 290 kDa antigen of EBA and 3 with sera bound BP antigens. Seven serum samples with epidermal and dermal combined staining, of which 5 of them reacted with BP antigens, 1 reacted with both BP and EBA antigens. One serum sample from each group showed a negative result by IB. Approximately 9.0% (7/78) of patients diagnosed with BP using regular methods were actually EBA. CONCLUSIONS: Epidermal reaction using the IIF-SSS assay highly correlated with the diagnosis of BP. However, dermal reactions correlated poorly with EBA, with some serum samples from BP patients binding to dermal-side antigens. In both epidermal and dermal stained sera using IIF-SSS, there was a possibility of BP and EBA. Differential diagnosis should be confirmed using IB, especially in cases of dermal and double staining patterns assayed using IIF-SSS.

Gene expression analysis of leprosy by using a multiplex branched DNA assay.

Leprosy is caused by Mycobacterium leprae, and the global registered prevalence of leprosy at the beginning of 2009 stood at 213,036 cases. It has long been thought that leprosy has a strong genetic risk. Recently, we have identified significant associations (P < 1.00 × 10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR and RIPK2 and a trend towards an association (P = 5.10 × 10(-5)) with a SNP in LRRK2. Here, we investigated the expression of these seven genes in formalin-fixed, paraffin-embedded skin tissues of leprosy and matched normal tissues using branched DNA technology. This technology allows for direct measurement of targeted mRNA within cellular lysate using a 96-well plate format in a time frame compared to a reporter gene assay. The clear upregulation of all seven genes was found in leprosy tissues compared to normal tissues, which further supports our genome-wide association study results.