It is very well known that the use of glucocorticoids can provoke a dose dependent bone loss, and therefore an increased risk of fracture. It is also very well known that currently glucocorticoids continue to be the mainstay of therapy when managing immunobullous skin diseases. Moreover, immunobullous skin diseases are frequently treated with high doses and long-term courses of glucocorticoids. Currently, bisphosphonates are considered as the first-line therapy in the prophylaxis of glucocorticoid-induced osteoporosis.

In a very interesting paper just published in the Archives of Dermatology, Dr. Shang-Ian Tee and collaborators present a placebo-controlled, 12-month randomized, double-blind trial,  focusing on the efficacy and safety of alendronate sodium (10 mg) with calcium plus vitamin D vs calcium plus vitamin D alone, administered orally to patients suffering from a newly diagnosed immunobullous disease.

29 patients were enrolled in the study: 15 in the alendronate group and 14 in the placebo group. The authors documented a statistically significant increase in bone mineral density compared with the placebo group at the lumbar spine (P=.01) and the femoral neck (P=.01). Adverse events occurred in both groups and were generally minor: headaches, rashes, dyspepsia and musculoskeletal pain.

Dr. Shang-Ian Tee and co-workers remind us that guidelines usually recommend treatment with bisphosphonates for patients who receive at least 7.5 mg of prednisone per day during 3 months, but they underline that these guidelines are based on patients suffering from non dermatological disorders. According to the authors this is the first controlled randomized study assessing the benefits of early bisphosphonate treatment in patients suffering from immunobullous skin diseases, a therapeutic strategy that they recommend in the everyday clinical practice.

Patients with dermatitis herpetiformis (DH) have always an associated gluten-sensitive enteropathy (GSE) that is frequently subclinical. The diagnosis of DH is based on the finding of granular deposits of IgA along the dermoepidermal junction and/or the dermal papillae by direct immunofluorescence, that can be found in all patients. However, these patients have circulating IgA antibodies directed against tissue transglutaminase (tTG), that correlate with the severity of GSE, and also indicate the adherence of this group of patients to a gluten-free diet. It has been recently shown that epidermal transglutaminase (eTG), an epidermal enzyme homologous to tTG, can be the autoantigen in patients with DH. In a recent study from Germany published in the July issue of the Journal of the American Academy of Dermatology the authors compared the levels of IgA autoantibodies against eTG and tTG tested by ELISA in a group of 52 patientswith DH. They found that when the patients were on a normal diet, 95% had autoantibodies against eTG, and 79% against tTG. In addition, they found that when the patients were on a gluten free diet and did not present any DH lesion, these autoantibodies were negative. The authors conclude that, in contrast to other previous studies, the eTG ELISA is currently the most sensitive serologic test for the diagnosis of DH. (more…)

Patients with pemphigus vulgaris (PV) and pemphigus foliaceus (PF) have circulating autoantibodies in their serum against the cell surface of keratinocytes. These antibodies are directed against two glycoproteins, members of the cadherin family that have been called desmogleins (Dsg). In PF the antigen is a 160-kD protein called Dsg1. In PV the main antigen is a 130-kD protein called Dsg3, although around 50% of the patients also have antibodies against Dsg1. These last group of patients corresponds to the ones with mucocutaneous lesions. In the last 10 years an ELISA test using the extracellular domain of Dsg1 and Dsg3 has been developed and used in clinical practice. This test was initially used as a tool for diagnosis, but it has also been employed as a tool for the follow up and monitoring of these patients.

In a recent study of Abasq and coworkers from France published in the May issue of the Archives of Dermatology, the authors investigated the real value of Dsg1 and Dsg3 ELISA test in the monitoring of patients with pemphigus. In a retrospective study of 26 pemphigus patients (19 with PV and 7 with PF) the authors show that there is dissociation between the ELISA values of antibodies against Dsg1 and Dsg3. They show that both in patients with PV and PF, there was a close correlation of antibodies against Dsg1 and disease activity, and that a high level of antibodies can have a good predictive value for the occurrence of a skin relapse in these patients. On the other side, antibodies against Dsg3 in PV did not have a good correlation with disease activity (most patients had high levels of antibodies independently of disease activity). This dissociation has to be known by the physicians taking care of these patients in order to take the optimal decisions when the ELISA titers are rising or are persistently high. (more…)