Successful pharmacological intervention at different levels of the complement system in an in vitro complement fixation model for bullous pemphigoid

Bullous pemphigoid (BP) is characterized by deposition of immunoglobulins and complement along the epidermal basement membrane (BM). In humans, there is a lack of functional studies targeting the complement system (CS). This study investigates activation of all complement pathways in BP skin biopsies. Moreover, pharmacological inhibition at different levels of the CS was investigated using anti-complement compounds in a complement fixation BP assay. In this retrospective study, 21 frozen biopsies from BP patients were stained by direct immunofluorescence for C1q, MBL, ficolin-2, C4d, properdin, C3c and C5b-9. Sera from 10 patients were analysed in a complement fixation assay in the presence of C1 inhibitor, anti-factor B monoclonal antibody (mAb), anti-C3 mAb and anti-C5 mAb and compared with dexamethasone. The two readouts were the quantity of complement deposited along the BM and the release of sC5b-9 in the supernatant. Our results show classical and alternative complement pathway activation in BP skin biopsies, but could not demonstrate significant lectin pathway activation. In contrast to dexamethasone, complement deposition along the BM could be selectively inhibited by anti-C1 and anti- factor B. More downstream, selective intervention at the level of C3 and C5 could effectively reduce complement deposition along the BM and the release of sC5b-9 in the supernatant. This study shows that selective intervention in either the classical, alternative or terminal pathway prevented deposition of complement along the BM in an in vitro BP model. The results of our study greatly encourage the clinical development of complement inhibitors for the treatment of BP.

Hedgehog pathway mutations are involved in the pathogenesis of plaque-type "trichoblastoma": A report of two cases

We present two cases of plaque-type trichoblastoma with atypical foci. A rare variant of trichoblastoma is the plaque variant, which is characterized by poor circumscription and locally infiltrative growth pattern. These lesions mostly require multiple stages of Mohs micrographic surgery. Debate still exists whether this variant should be considered as a benign entity or as "low-grade" malignant counterpart of trichoblastoma. In this report we describe two cases of plaque-type trichoblastoma with atypical foci, which harbored somatic mutations in the Hedgehog pathway, thus should be acknowledged as intermediate malignancies. In addition, extensive molecular workup of both the trichoblastic and atypical component in sequential lesions in the same patient was performed.

Complement activation in Hidradenitis suppurativa: Covert low-grade inflammation or innocent bystander?

Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin disease with a complex and multifactorial pathogenesis involving both the innate and adaptive immune system. Despite limited evidence for local complement activation, conflicting results have been published on the role of systemic complement activation in HS. It was hypothesized that complement was consumed in highly inflamed HS skin, trapping complement from the circulation. Therefore, the aim of this study was to evaluate this local complement deposition in HS skin lesions using routine and commonly used complement antibodies.Direct immunofluorescence for C1q, C3c, C4d, C5b-9, and properdin was performed on frozen tissue sections of 19 HS patients and 6 controls. C5a receptor 1 (C5aR1) was visualized using immunohistochemistry.

Overall, we found no significant local complement deposition in HS patients versus controls regarding C1q, C3c, C4d, C5b-9, or properdin on either vessels or immune cells. C5aR1 expression was exclusively found on immune cells, predominantly neutrophilic granulocytes, but not significantly different relatively to the total infiltrate in HS lesions compared with controls. In conclusion, despite not being able to confirm local complement depositions of C1q, C3c, C4d, or properdin using highly sensitive and widely accepted techniques, the increased presence of C5aR1 positive immune cells in HS suggests the importance of complement in the pathogenesis of HS and supports emerging therapies targeting this pathway.

Trichoblastic carcinosarcoma with panfollicular differentiation (panfollicular carcinosarcoma) and CTNNB1 (beta-catenin) mutation

We present a case of trichoblastic carcinosarcoma with panfollicular differentiation. An 80-year-old man presented with a lesion on the left ear, which had been present for several months. Histopathology revealed a well-demarcated neoplasm in the dermis composed of intimately intermingled malignant epithelial and mesenchymal cells. The epithelial component showed multilineage follicular differentiation toward all of the elements of a normal hair follicle. Molecular analysis revealed identical molecular aberrations in both epithelial and mesenchymal components including CTNNB1 and SUFU mutations. To the best of our knowledge, this is the first report of panfollicular carcinosarcoma and of the presence of a CTNNB1 mutation in trichoblastic carcinosarcoma.

Complement Activation in Inflammatory Skin Diseases

The complement system is a fundamental part of the innate immune system, playing a crucial role in host defense against various pathogens, such as bacteria, viruses, and fungi. Activation of complement results in production of several molecules mediating chemotaxis, opsonization, and mast cell degranulation, which can contribute to the elimination of pathogenic organisms and inflammation. Furthermore, the complement system also has regulating properties in inflammatory and immune responses. Complement activity in diseases is rather complex and may involve both aberrant expression of complement and genetic deficiencies of complement components or regulators. The skin represents an active immune organ with complex interactions between cellular components and various mediators. Complement involvement has been associated with several skin diseases, such as psoriasis, lupus erythematosus, cutaneous vasculitis, urticaria, and bullous dermatoses. Several triggers including auto-antibodies and micro-organisms can activate complement, while on the other hand complement deficiencies can contribute to impaired immune complex clearance, leading to disease. This review provides an overview of the role of complement in inflammatory skin diseases and discusses complement factors as potential new targets for therapeutic intervention.

Editor's Choice - Five Year Results of Great Saphenous Vein Treatment: A Meta-analysis

OBJECTIVES

The most frequently used treatment options for great saphenous vein incompetence are high ligation with stripping (HL+S), endovenous thermal ablation (EVTA), mainly consisting of endovenous laser ablation (EVLA) or radiofrequency ablation, and ultrasound guided foam sclerotherapy (UGFS). The objective of this systematic review and meta-analysis was to compare the long-term efficacy of these different treatment modalities.

METHODS

A systematic literature search was performed. Randomised controlled trials (RCTs) with follow-up ≥ 5 years were included. Pooled proportions of anatomical success, which was the primary outcome, rate of recurrent reflux at the saphenofemoral junction (SFJ), and mean difference in venous clinical severity score (VCSS) were compared using a z test or Student t test. Quality of life data were assessed and described.

RESULTS

Three RCTs and 10 follow-up studies of RCTs were included of which 12 were pooled in the meta-analysis. In total, 611 legs were treated with EVLA, 549 with HL+S, 121 with UGFS, and 114 with HL+EVLA. UGFS had significantly lower pooled anatomical success rates than HL+S, EVLA, and EVLA with high ligation: 34% (95% CI 26-44) versus 83% (95% CI 72-90), 88% (95% CI 82-92), and 88% (95% CI 17-100) respectively; p ≤ .001. The pooled recurrent reflux rate at the SFJ was significantly lower for HL+S than UGFS (12%, 95% CI 7-20, vs. 29%, 95% CI 21-38; p ≤ .001) and EVLA (12%, 95% CI 7-20, vs. 22%, 95% CI 14-32; p = .038). VCSS scores were pooled for EVLA and HL+S, which showed similar improvements.

CONCLUSION

EVLA and HL+S show higher success rates than UGFS 5 years after GSV treatment. Recurrent reflux rates at the SFJ were significantly lower in HL+S than UGFS and EVLA. VCSS scores were similar between EVLA and HL+S.

Randomized clinical trial of 940- versus 1470-nm endovenous laser ablation for great saphenous vein incompetence

Background

The independent effect of wavelength used for endovenous laser ablation (EVLA) on patient-reported outcomes, health-related quality of life (HRQoL), treatment success and complications has not yet been established in a randomized clinical trial. The aim was to compare two different wavelengths, with identical energy level and laser fibres, in patients undergoing EVLA.

Methods

Patients with great saphenous vein incompetence were randomized to receive 940- or 1470-nm EVLA. The primary outcome was pain at 1 week. Secondary outcomes were: patient satisfaction, duration of analgesia use and time without normal activities assessed at 1 week; HRQoL after 12 weeks; treatment success after 12 and 52 weeks; change in Venous Clinical Severity Score (VCSS) after 12 weeks; and adverse events at 1 and 12 weeks.

Results

A total of 142 legs were randomized (940-nm EVLA, 70; 1470-nm EVLA, 72). Patients in the 1470-nm laser group reported significantly less pain on a visual analogue scale than those in the 940-nm laser group: median (i.q.r.) score 3 (2–7) versus 6 (3–8) (P = 0·004). Duration of analgesia use was significantly shorter after 1470-nm EVLA: median (i.q.r.) 1 (0–3) versus 2 (0–5) days (P = 0·037). HRQoL and VCSS improved equally in both groups. There was no difference in treatment success rates. Complications were comparable in both groups, except for more superficial vein thrombosis 1 week after 1470-nm EVLA.

Conclusion

EVLA using a 1470-nm wavelength fibre was associated with improved postoperative pain and a reduction in analgesia use in the first week after surgery compared with use of a 940-nm fibre. Treatment success and adverse event rates were similar. Registration number: NCT01637181 (http://www.clinicaltrials.gov).