Infantile haemangioma: new aspects on the pathogenesis of the most common skin tumour in children

Overexpression of VEGFα as a biomarker of endothelial dysfunction in aortic tissue of α-GAL-Tg/KO mice and its upregulation in the serum of patients with Fabry's disease

Introduction

Fabry's disease is an X-linked lysosomal storage disorder caused by reduced activity of α-galactosidase A (GAL), leading to premature death on account of renal, cardiac, and vascular organ failure. Accumulation of the GAL substrate globotriaosylceramide (Gb3) in endothelial and smooth muscle cells is associated with early vascular cell damage, suggesting endothelial dysfunction as a driver of cardiorenal organ failure. Here, we studied the vascular expression of the key angiogenic factors, VEGFα and its antagonist angiostatin, in Fabry α-GAL-Tg/KO mice and determined circulating VEGFα and angiostatin serum levels in patients with Fabry's disease and healthy controls.

Methods

Cryopreserved aortic vessels from six α-GAL-Tg/KO and six wild-type (WT) mice were obtained and VEGFα and angiostatin levels were determined by performing Western blot analysis. VEGFα expression was visualized by an immunohistochemical staining of paraffin aortic rings. In addition, VEGFα and angiostatin serum levels were measured by using an enzyme-linked immunosorbent assay in 48 patients with genetically verified Fabry's disease (50% male) and 22 healthy controls and correlated with disease severity markers such as lyso-Gb3, albuminuria, NTproBNP, high-sensitive troponin T (hsTNT), and myocardial wall thickness.

Results

It was found that there was a significant increase in VEGFα protein expression (1.66 ± 0.35 vs. 0.62 ± 0.16, p = 0.0009) and a decrease in angiostatin expression (0.024 ± 0.007 vs. 0.053 ± 0.02, p = 0.038) in aortic lysates from α-GAL-Tg/KO compared with that from WT mice. Immunohistochemical staining revealed an adventitial VEGFα signal in α-GAL-Tg/KO mice, whereas no VEGFα signal could be detected in WT mice aortas. No differences in aortic angiostatin expression between α-GAL-Tg/KO- and WT mice could be visualized. The serum levels of VEGFα were significantly upregulated in patients with Fabry's disease compared with that in healthy controls (708.5 ± 426.3 vs. 458.5 ± 181.5 pg/ml, p = 0.048) and positively associated with albuminuria (r = 0.82, p < 0.0001) and elevated NTproBNP (r = 0.87, p < 0.0001) and hsTNT values (r = 0.41, p = 0.048) in male patients with Fabry's disease. For angiostatin, no significant difference was found between patients with Fabry's disease and healthy controls (747.6 ± 390.3 vs. 858.8 ± 599.3 pg/ml).

Discussion

In conclusion, an overexpression of VEGFα and downregulation of its counter player angiostatin in aortic tissue of α-GAL-Tg/KO mice support the hypothesis of an underlying vasculopathy in Fabry's disease. Elevated VEGFα serum levels were also observed in patients with Fabry's disease and were positively associated with elevated markers of organ manifestation in males. These findings suggest that angiogenetic markers, such as VEGFα, may be potentially useful biomarkers for the detection of endothelial dysfunction in classical Fabry's disease.

The flavonoid luteolin suppresses infantile hemangioma by targeting FZD6 in the Wnt pathway

Infantile hemangioma is the most common vascular tumor of childhood. It is characterized by clinical expansion of endothelial cells and promoted by angiogenic factors. Luteolin is a flavonoid compound that carries anti-cancer and anti-angiogenesis properties. The study aimed to investigate the effect of luteolin in treating infantile hemangioma. We first tested the effect of luteolin on cell proliferative potential and VEGFA expression in hemangioma-derived stem cells (HemSCs). We then examined the efficacy of systemic application of luteolin in a murine hemangioma model. We then identified the downstream factor regulated by luteolin in HemSCs and validated its causative relationship with knock-down method in both in vitro and in vivo models. We also investigated the protein expression change of this targeting factor in proliferating hemangiomas. Luteolin inhibited HemSC growth and suppressed VEGF-A expression in a dose-dependent manner. Luteolin inhibited microvessel formation and de novo vasculogenesis in the murine model. FZD6 was induced by luteolin and exerted the anti-angiogenesis effect in our tumor models. Lastly, FZD6 level was repressed in the clinical tissues of human proliferating hemangiomas. Luteolin is a promising new agent to treat infantile hemangioma. Targeting the Wnt pathway may represent a potential therapeutic strategic to inhibit angiogenesis in proliferating hemangiomas.

Vascular Birthmarks as a Clue for Complex and Syndromic Vascular Anomalies

Vascular birthmarks are common in neonates (prevalence: 20-30%) and mostly incidental findings sometimes with spontaneous regression (salmon patch and nevus simplex). Capillary malformations are found in about 1% and infantile hemangiomas are found in 4% of mature newborns. Vascular malformations are classified according to their most prominent vessel type. The term "capillary malformation" (port wine stain) includes a wide range of vascular lesions with different characteristics; they may be isolated or part of specific syndromic conditions. Part of the infantile hemangiomas and of the vascular malformations may require treatment for functional or cosmetic reasons, and in rare cases, investigations are also necessary as they represent a clue for the diagnosis of complex vascular malformation or tumors associated with extracutaneous abnormalities. Complex vascular malformations are mostly mosaicism due to early somatic mutations. Genetic advances have led to identify the main pathogenic pathways involved in this disease group. Diffuse capillary malformation with overgrowth, Klippel-Trenaunay syndrome, CLAPO syndrome, CLOVES syndrome, and megalencephaly-capillary malformation belong to the PIK3CA-related overgrowth. Capillary malformation-arteriovenous malformation underlies a fast-flow vascular malformation, sometimes manifesting as Parkes-Weber syndrome. Recognition of these different types of capillary vascular stains is sometimes difficult; however, associated findings may orient the clinicians while genetic testing may confirm the diagnosis. Lymphatic malformation frequently manifests as large masses that compress and/or infiltrate the surrounding tissues, representing a neonatal emergency when airways are involved. Infantile hemangiomas may cause functional and/or permanent esthetical damage, depending on their localization (such as periorbital area, lip, nose); large (more than 5 cm) infantile hemangiomas with a segmental distribution can be associated with obstruction or malformations of the underneath organs with complications: PHACE syndrome, LUMBAR/SACRAL syndrome, and beard infantile hemangioma. In our review, we discuss controversies regarding the international classification and emerging concepts in the field of vascular anomalies. Finally, we discuss potential developments of new, non-invasive diagnostic techniques and repurposing of target therapies from oncology. Complex and/or life-threatening vascular tumors and malformations are extremely rare events and they represent a considerable therapeutic challenge. Early recognition of clinical signs suggestive for a specific disease may improve therapeutic outcomes and avoid severe complications.

Antiangiogenic potential of beta-blockers in the context of juvenile hemangioma treatment

Juvenile hemangiomas (JH) — the most common tumor of childhood, which is estimated by various investigators found in 3–10 % of newborns resulting from the local development of significant violations of neoangiogenesis regulation. Research objective: determination of comparative antiangiogenic effectiveness and influence of beta-blockers on the level of a vascular endothelial factor of growth in an experiment. Material and methods. For determination of antiangiogenic effect of beta blockers, comparative studying of their influence on the level of a vascular endothelial factor of growth in an experiment on 72 nonlinear laboratory rats, by average weight 180 ± 20 g which were conditionally divided into 6 groups is executed: 1 — control, 2 — negative control — experimental ischemia (EI, crossing of femoral vessels), 3 — positive control (EI with bevacizumab introduction), 4 — EI with introduction of a timolol, 5 — EI with introduction of a betaksolol, 6 — EI with introduction of interferon alpha 2b. Results. The VEGF levels were: in 1 group — 1.50 ± 0.3 pg/ml, in 2 — 20.3 ± 3.2 pg/ml, 3 — 5.8 ± 0.9 pg/ml, 4 — 13.8 ± 1.4 pg/ml, 5 — 19.2 ± 2.3 pg/ml and 6 — 11.1 ± 2.2 pg/ml. Results of microscopy and immunohistochemical research demonstrate lack of activation of processes of neoangiogenesis in 1 group of animals. At animals of 2nd and 5th groups along with the expressed inflammatory processes the neoangiogenesis phenomena are established. Conclusion. Beta-blockers show the direct or mediated negative impact on synthesis of VEGF and oppression of neoangiogenesis. The activity of selective beta-blocker concerning neoangiogenesis suppression — was lower in comparison by activity non-selective that allows to consider the Timolol effective antiangiogenic remedy.

Exploring the association between chorangioma and infantile haemangioma in singleton and multiple pregnancies: a case-control study in a Swedish tertiary centre

OBJECTIVES

Placenta or placental chorangioma could be the origin site of infantile haemangioma since they share various histochemical and genetic characteristics with placental vascular tissue. The aim of the current study was to investigate the association between chorangiomas and infantile haemangiomas in singleton and multiple pregnancies.

MATERIALS AND METHODS

An informative questionnaire enquiring about the presence or not of infantile haemangioma and including illustrative photos of haemangioma was sent to 469 (153 cases with chorangioma and 316 controls) mothers of 323 singleton (104 cases and 219 controls) and 146 multiple (49 cases and 97 controls) liveborn neonates registered in Sweden. Overall, 310 mothers (66.1%) from 216 singleton and 94 multiple pregnancies (96 cases and 214 controls) provided feedback and their consent to participate in the current case-control study.

RESULTS

The incidence of infantile haemangioma showed no statistically significant differences between cases and controls (18.8% vs 18.2%) or between singleton and multiple pregnancies (18.9% vs 17.0%). The frequency of pre-eclampsia was significantly higher in cases with chorangioma compared with controls (41.7% vs 24.3%, OR=2.22, 95% CI 1.33 to 3.71, p=0.0022) and in singleton compared with multiple pregnancies (33.3% vs 21.3%, OR=1.85, 95% CI 1.04 to 3.26, p=0.034), whereas there were no significant differences in the incidence of infantile haemangioma in neonates of mothers with or without pre-eclampsia or in neonates of mothers with multiple compared with singleton pregnancies.

CONCLUSION

There was no association between placental chorangiomas and infantile haemangiomas. Multiple pregnancies or pre-eclampsia were not significantly related to higher incidence of infantile haemangioma.

Interdisciplinary Management of Head and Neck Vascular Anomalies: Clinical Presentation, Diagnostic Findings and Minimalinvasive Therapies

OBJECTIVES

Vascular anomalies are included in the 30 000 rare diseases worldwide affecting less than 5/10 000 people. Depending on their morphology and biological properties, they can cause varied disorders with organ involvement. Almost 60% of vascular anomalies have a predilection for the head and neck region in children. Clinical and scientific effort to establish interdisciplinary management concepts for vascular anomalies is increasing worldwide.

METHODS

Especially in the head and neck region, clinical impairment and organ dysfunction is associated with cosmetic issues that may represent a physical and psychological issue for the patient. Correct diagnosis, based on clinical presentation and symptoms, is a prerequisite for appropriate therapy, ranging from conservative management to a spectrum of minimally invasive treatment options. We searched PubMed for German and English language published data until December 2016 with focus on clinical studies, review articles and case reports on vascular anomalies with a focus on the head and neck region.

RESULTS

The last ISSVA update in 2014 has contributed to a better understanding of vascular anomalies, classifying them in vascular tumors and vascular malformations. The predominant representatives of vascular tumors are congenital and infantile hemangiomas. Infantile hemangiomas have the ability of spontaneous regression in more than 80%. Patients with symptomatic growing hemangiomas with ulcerations, bleeding complications and restriction of hearing, swallowing disorder, impairment of vision, or cosmetic dysfigurement require treatment. Therapies include oral propanolol, transcatheter embolization and surgery. Vascular malformations tend to progress with patientś age and are subdivided in slow flow and fast flow lesions. Symptomatic slow flow lesions, e.g. venous and lymphatic malformations, benefit from percutaneous sclerotherapy. Fast flow lesions, as arteriovenous malformations, are rare but undoubtedly therapeutically the most challenging vascular anomaly. Depending on location and size, they may require multiple transcatheter embolization procedures for successful occlusion of the AVM.

CONCLUSIONS

This review provides knowledge on the current ISSVA classification of vascular anomalies, their clinical presentation, diagnostic evaluation and minimally invasive therapy options to encourage the establishment of a comprehensive interdisciplinary management for head and neck vascular anomalies.

Infantile Hemangiomas in Twins: A Prospective Cohort Study

BACKGROUND

Twins have a higher-than-expected risk of infantile hemangiomas (IHs), but the exact reasons for this association are not clear. Comparing concordant and discordant twin pairs might help elucidate these factors and yield more information about IH risk factors.

METHODS

A prospective cohort study of twin pairs from 12 pediatric dermatology centers in the United States, Canada, Argentina, and Spain was conducted. Information regarding maternal pregnancy history, family history of vascular birthmarks, zygosity (if known), and pregnancy-related information was collected. Information regarding twins (N = 202 sets) included birthweight, gestational age (GA), presence or absence of IHs, numbers and subtypes of IHs, presence of other birthmarks, and other medical morbidities.

RESULTS

Two hundred two sets of twins were enrolled. Concordance for IH was present in 37% of twin pairs. Concordance for IH was inversely related to gestational age (GA), present in 42% of GA of 32 weeks or less, 36% of GA of 33 to 36 weeks, and 32% of GA of 37 weeks or more. Twins of GA of 34 weeks or less were more than two and a half times as likely to be concordant as those of GA of 35 weeks or more (odds ratio (OR) = 2.66, 95% confidence interval (CI) = 1.42-4.99; p < 0.01). In discordant twins, lower birthweight conferred a high risk of IH; of the 64 sets of twins with 10% or greater difference in weight, the smaller twin had IH in 62.5% (n = 40) of cases, versus 37.5% (n = 24) of cases in which the higher-birthweight twin was affected. Zygosity was reported in 188 twin sets (93%). Of these, 78% were dizygotic and 22% monozygotic. There was no statistically significant difference in rates of concordance between monozygotic twins (43%, 18/42) and dizygotic twins (36%, 52/146) (p = 0.50). In multivariate analysis comparing monozygotic and dizygotic twins, adjusting for effects of birthweight and sex, the likelihood of concordance for monozygotic was not appreciably higher than that for dizygotic twins (OR = 1.14, 95% CI = 0.52-2.49). Female sex also influenced concordance, confirming the effects of female sex on IH risk. The female-to-male ratio was 1.7:1 in the entire cohort and 1.9:1 in those with IH. Of the 61 concordant twin sets with known sex of both twins, 41% were female/female, 43% were female/male, and 16% were male/male.

CONCLUSIONS

These findings suggest that the origin of IHs is multifactorial and that predisposing factors such as birthweight, sex, and GA may interact with one another such that a threshold is reached for clinical expression.

Propranolol for infantile hemangioma: Current state of affairs

Infantile hemangioma (IH) is the most common benign tumor seen in infancy. This review provides up-to-date information on the pathophysiology, variations in clinical presentation, and natural history of IH, elaborating on associated anomalies, such as PHACE(S) syndrome and LUMBAR syndrome. Because of the benign and self-limiting characteristics seen in more than 90% of cases of IH, a conservative approach is usually chosen. However, some circumstances, such as ulceration, vision loss, breathing difficulties, or potential disfigurement, will require treatment during the proliferative phase. For decades, treatment of IH has primarily consisted of corticosteroids or surgery. Since 2008, propranolol has become the treatment of first choice. In this article, we bring to light the crucial changes in the treatment of IH over the past years. To date, there is still a lack of data on the possible long-term effects of propranolol treatment in young infants. A theoretical probability of the central nervous system being affected (that is, impairment of short- and long-term memory, psychomotor function, sleep quality, and mood) has recently been suggested. This review highlights research topics concerning these long-term adverse effects. Finally, information is provided on the potential instruments to measure IH severity and activity in clinical trials and/or in clinical practice and the recently developed and first-validated IH-specific quality-of-life questionnaire.

Educational paper: Pathogenesis of infantile haemangioma, an update 2014 (part I)

Infantile haemangioma (IH) is the most frequent childhood tumour. Although it is benign and self-limiting, severe complications can arise due to localisation and fast tumour growth. Management and therapy of IH has changed greatly after 2008 with propranolol. However, the pathogenesis remains elusive. This update provides an overview of all possible mechanisms currently considered. We discuss the possibility that several mechanisms act together, although local hypoxia seems to be important. Clinically, in about half of the cases, an IH is preceded by an anaemic macula (local ischaemia) or a so-called precursor lesion. Laboratory findings indicate stabilisation and an increased transcription activity of hypoxia-inducible factor 1 alpha (HIF1α), leading to up-regulation of its downstream target genes (such as vascular endothelial growth factor (VEGF)), which normally occurs in cases of hypoxia.

CONCLUSION

Three main hypotheses have been proposed, namely (1) the theory of tissue hypoxia, (2) the theory of embolization of placental endothelial cells and (3) the theory of increased angiogenic and vasculogenic activity.

Vascular endothelial growth factor (VEGF-a) in Fabry disease: association with cutaneous and systemic manifestations with vascular involvement

INTRODUCTION

Fabry disease is an X-linked inherited metabolic disorder characterized by the deficiency of lysosomal α-galactosidase A enzyme. This leads to the accumulation, into lysosomes through the body, of glycosphingolipids, mainly Gb3. Skin involvement and progressive multi-organ failure are usually observed. Endothelium is the preferential target of the Gb3 storage that determines endothelial dysfunction and vasculopathy leading to the clinical manifestations of the disease. The serum levels of Vascular Endothelial Growth Factor-A (VEGF-A), a specific endothelial cell mitogen, were analyzed in Fabry patients to explore a possible association to the clinical manifestations with vascular involvement.

METHODS

Thirty-five patients with a biochemical and genetic diagnosis of Fabry disease, along with an age-gender-matched healthy control group, were enrolled. Serum samples were collected and analyzed by ELISA. The genetic mutations, the specific organ dysfunction, and the cardiovascular risk factors such as dyslipidaemia, diabetes, smoking habits and hypertension were evaluated in Fabry patients.

RESULTS

The mean serum level of VEGF-A in Fabry patients group was significantly higher than in the control group (P=0.006). A statistical significant association, between VEGF-A levels and the skin manifestation including angiokeratomas, sweating abnormalities and Fabry Facies was found. An association was also found between high VEGF-A and specific GLA mutations, the male gender, the renal and neurological manifestations, the presence of eye vessels tortuosity, smoking habit and hypertension.

CONCLUSIONS

We detected increased VEGF-A levels in patients with Fabry disease compared to the controls, and we hypothesized that this could be a response to the vascular damage characterising this lysosomal disorder. However, further studies are necessary to clarify the role of VEGF-A in Fabry.