Itch in dermatomyositis: the role of increased skin interleukin-31

[Juvenile dermatomyositis: A series of 22 cases]

PURPOSE

To report on the characteristics of juvenile dermatomyositis (JDM).

PATIENTS AND METHODS

This was a retrospective, descriptive, cross-sectional, non-interventional, multicenter study conducted in Alsace between 2000 and 2015. The patients, aged 0 to 16years, had JDM according to both the Bohan and Peter and the EULAR/ACR criteria.

RESULTS

A total of 17 girls and 5 boys were included with a median age at disease onset of 7,8years (Q1-Q3: 4.4-12.9). Median duration of JDM and median patient follow-up were 2.8years and 6.2years, respectively. The most common skin symptoms were papules or Gottron's sign (86 %), nail lesions (82 %), erythema of the face (77 %) and eyelids (59 %), photosensitivity (59 %), and calcinosis (27 %). One patient presented papules with a depressed and porcelain-white center ("Degos-like" lesions). One patient had algodystrophy. Two patients were clinically amyopathic. One girl had intestinal vasculitis. Respiratory function tests were abnormal in 27 % of cases. Median treatment duration was 42 months (Q1-Q3: 19-63). Three patients had a monocyclic form, 12 had a polycyclic form, and 7 had chronic disease.

CONCLUSION

The frequency of cutaneous and musculoskeletal signs is comparable to that of other large cohorts of JDM. "Degos-like" lesions and algodystrophy have not yet been described in JDM. This study highlights the type and extent of the dermatological manifestations that frequently constitute the presenting complaint in this disease.

Dermatomyositis: An Update on Diagnosis and Treatment

Dermatomyositis is a rare inflammatory disease with characteristic cutaneous findings and varying amounts of systemic involvement. Patients may present with skin disease alone, have concomitant muscle disease, or have extracutaneous manifestations such as pulmonary disease or an associated malignancy. Given such diverse presentations, dermatomyositis is both a diagnostic and therapeutic challenge. However, a prompt diagnosis is of utmost importance to institute adequate therapy and screen patients for an associated malignancy. Dermatologists should play a crucial role in the diagnosis and management of patients with dermatomyositis as cutaneous disease tends to be chronic, negatively impact quality of life, and be more recalcitrant to therapy. In this review, we discuss diagnosis, with a focus on myositis-specific antibodies and their associated phenotypes. We also review therapies available for this often refractory skin disease.

Trial of Nemolizumab in Moderate-to-Severe Prurigo Nodularis

BACKGROUND

Prurigo nodularis is a chronic pruritic skin disease with multiple nodular skin lesions. Nemolizumab is a monoclonal antibody targeting the interleukin-31 receptor, which is involved in the pathogenesis of prurigo nodularis.

METHODS

We conducted a 12-week, randomized, double-blind, phase 2 trial of nemolizumab (at a dose of 0.5 mg per kilogram of body weight) administered subcutaneously at baseline, week 4, and week 8, as compared with placebo, in patients with moderate-to-severe prurigo nodularis and severe pruritus. Moderate-to-severe prurigo nodularis was defined as 20 or more nodules, and severe pruritus was defined as a mean score of at least 7 for the worst daily intensity of pruritus on the numerical rating scale (scores range from 0 [no itch] to 10 [worst itch imaginable]). The primary outcome was the percent change from baseline in the mean peak score for pruritus on the numerical rating scale at week 4. Secondary outcomes included additional measures of itching and disease severity. Safety assessments were performed through week 18.

RESULTS

A total of 70 patients were randomly assigned in a 1:1 ratio to receive nemolizumab (34 patients) or placebo (36). The initial pruritus score on the numerical rating scale was 8.4 in each group. At week 4, the peak pruritus score on the numerical rating scale was reduced from baseline by 4.5 points (change, -53.0%) in the nemolizumab group, as compared with a reduction of 1.7 points (change, -20.2%) in the placebo group (difference, -32.8 percentage points; 95% confidence interval, -46.8 to -18.8; P<0.001). Results for secondary outcomes were in the same direction as for the primary outcome. Nemolizumab was associated with gastrointestinal symptoms (abdominal pain and diarrhea) and musculoskeletal symptoms.

CONCLUSIONS

Nemolizumab resulted in a greater reduction in pruritus and severity of skin lesions than placebo in patients with prurigo nodularis but was associated with adverse events. Larger and longer trials are needed to determine the durability and safety of nemolizumab for the treatment of prurigo nodularis. (Funded by Galderma; ClinicalTrials.gov number, NCT03181503.).

Introducing nitrogen atoms to amidoalkylindoles: potent and selective cannabinoid type 2 receptor agonists with improved aqueous solubility

Previously we identified a series of amidoalkylindoles as potent and selective CB2 partial agonists. In the present study, we report our continuous effort to improve the aqueous solubility by introducing N atoms to the amidoalkylindole framework. Synthesis, characterization, and pharmacology evaluations were described. Bioisosteric replacements of the indole nucleus with an indazole, azaindole and benzimidazole were explored. Benzimidazole 43 (EC50,CB1 = NA, EC50,CB2 = 0.067 μM) and azaindole 24 (EC50,CB1 = NA, EC50,CB2 = 0.048 μM) were found to be potent and selective CB2 receptor partial agonists, both with improved aqueous solubility.

Role of the Pruritic Cytokine IL-31 in Autoimmune Skin Diseases

Many autoimmune skin diseases, such as bullous pemphigoid (BP), psoriasis and certain types of chronic urticaria, are associated with intensive pruritus. While histamine and neuropeptides have previously been ascribed to play a role in itch that accompanies these diseases, recent evidence suggests that the pruritogenic cytokine interleukin (IL)-31 is a major driver of pruritic responses. IL-31 was originally shown to be produced by activated helper T cells, particularly Th2 cells, mast cells, macrophages and dendritic cells. However, more recent evidence demonstrated that eosinophils are a major source of this cytokine too, particularly in bullous pemphigoid. Basophils have also been shown to express the cytokine which, through autocrine action, strongly supports the production of other Th2-type cytokines from these cells. These investigations suggest that the dynamic recruitment of eosinophils and basophils in some autoimmune skin diseases could play an important role in the severity of IL-31-mediated itch. Furthermore, these studies suggest that IL-31, in addition to its pruritic actions, also has potential immunomodulatory roles in terms of supporting Th2-type immunity, which often underpins IgE-associated autoimmune diseases (such as bullous pemphigoid and urticaria) as well as allergies. While the role of IL-31 in psoriasis remains to be clarified, current evidence shows that this cytokine plays a major role in BP, chronic spontaneous urticaria and dermatomyositis. This suggests potential use of IL-31 receptor-blocking therapeutic approaches (e.g., Nemolizumab) for the treatment of IL-31-associated disorders.

[What's new in internal medicine?]

What's new in internal medicine will be dedicated to three topics: i) inflammatory myopathies constituting a heterogenous group of diseases whose clinical manifestations, immunological abnormalities, treatment response and outcomes vary widely; ii) alterations of gut microbiota contributing to the occurrence or development of a range of conditions, including autoimmune diseases for which further work is necessary to understand the correlation of dysbiosis with these diseases; iii) the reciprocal relationship between obesity, metabolic syndrome, atherosclerosis and autoimmune diseases. New data concerning systemic sclerosis, cutaneous vasculitis, adult Still's disease, autoantibodies anti DFS70, Epstein Barr virus and autoimmune diseases were also highlighted.