Prenatal Risk Factors for PHACE Syndrome: A Study Using the PHACE Syndrome International Clinical Registry and Genetic Repository

The cause of PHACE syndrome is unknown. In a study of 218 patients, we examined potential prenatal risk factors for PHACE syndrome. Rates of pre-eclampsia and placenta previa in affected individuals were significantly greater than in the general population. No significant risk factor differences were detected between male and female subjects.

Congenital cardiac, aortic arch, and vascular bed anomalies in PHACE syndrome (from the International PHACE Syndrome Registry)

PHACE syndrome represents the association of large infantile hemangiomas of the head and neck with brain, cerebrovascular, cardiac, ocular, and ventral or midline defects. Cardiac and cerebrovascular anomalies are the most common extracutaneous features of PHACE, and they also constitute the greatest source of potential morbidity. Congenital heart disease in PHACE is incompletely described, and this study was conducted to better characterize its features. This study of the International PHACE Syndrome Registry represents the largest central review of clinical, radiologic, and histopathologic data for cardiovascular anomalies in patients with PHACE to date. Sixty-two (41%) of 150 subjects had intracardiac, aortic arch, or brachiocephalic vessel anomalies. Aberrant origin of a subclavian artery was the most common cardiovascular anomaly (present in 31 (21%) of 150 subjects). Coarctation was the second most common anomaly, identified in 28 (19%) of 150 subjects, and can be missed clinically in patients with PHACE because of the frequent association of arch obstruction with aberrant subclavian origin. Twenty-three (37%) of 62 subjects with cardiovascular anomalies required procedural intervention. A greater percentage of hemangiomas were located on the left side of the head and neck in patients with coarctation (46% vs 39%); however, hemangioma distribution did not predict the presence of cardiovascular anomalies overall. In conclusion, PHACE is associated with a high risk of congenital heart disease. Cardiac and aortic arch imaging with detailed assessment of arch patency and brachiocephalic origins is essential for any patient suspected of having PHACE. Longitudinal investigation is needed to determine the long-term outcomes of cardiovascular anomalies in PHACE.

Hypopituitarism in PHACES Association

The association consisting of posterior fossal malformations, cervicofacial, hemangiomas, arterial anomalies, cardiac defects, eye anomalies, and sternal clefting, or supraumbilical raphe, refers to the occurrence of congenital structural and vascular anomalies in the presence of a facial hemangioma. We report a patient with this association, growth retardation, and developmental delay who was found to have a partially empty sella turcica, central hypothyroidism, and growth hormone deficiency. Endocrinologic evaluation should be considered in any infant with this association.

Activation of neutrophils in cutaneous T-cell lymphoma

PURPOSE

Cutaneous T-cell lymphoma (CTCL) is a spectrum of disease of unknown etiology defined by infiltrates of activated and malignant T cells in the skin. In working with blood from CTCL patients, we noticed frequent activation of neutrophils; therefore, we tested the hypothesis that neutrophils are activated in CTCL subjects compared with normal healthy controls.

EXPERIMENTAL DESIGN

Using peripheral blood of 44 subjects with CTCL and 15 normal controls, we examined three measures of neutrophil activation. These are the presence of neutrophils of reduced buoyant density, the presence of primed neutrophils in a stimulated chemiluminescence assay, and changes in surface markers by flow cytometry. In addition, we tested plasma interleukin-8 (IL-8) and leukotriene B4 (LTB4) levels using ELISA.

RESULTS

A significantly larger fraction of hypodense neutrophils was observed in CTCL subjects compared with normals (10.6 +/- 1.7% versus 1.5 +/- 0.4%). Stimulated chemiluminescence was also significantly increased in CTCL, and analysis of neutrophil surface markers using flow cytometry showed significantly increased CD11b and CD66b and decreased CD62L, consistent with neutrophil activation. These changes were present even in early stages of CTCL. We further found that plasma IL-8 and LTB4 levels are elevated in CTCL, which could form a feedback loop contributing to disease pathophysiology.

CONCLUSIONS

CTCL is associated with systemic neutrophil activation, even in early disease, and a feedback loop between neutrophils and T cells mediated by IL-8 and LTB4 is a potential contribution to the pathophysiology of CTCL.

Skin-derived interleukin-7 contributes to the proliferation of lymphocytes in cutaneous T-cell lymphoma

Cutaneous T-cell lymphomas (CTCLs) are malignancies of T cells that have a special affinity for the skin. We have previously reported that much of the T-cell receptor repertoire is altered in CTCL, and both malignant and nonmalignant clones are numerically expanded, presumably in response to T-cell trophic cytokines. We therefore examined levels of the T-cell trophic cytokines IL-2, IL-4, IL-7, IL-12, IL-13, and IL-15 in plasma in 93 CTCL patients and healthy controls. Only IL-7 levels were elevated in CTCL. We next looked at lesional skin from patients with CTCL and found elevated levels of IL-7 mRNA. Explant cultures of normal and lesional CTCL skin biopsies revealed significantly more IL-7 protein production in CTCL skin. Additionally, cultures of CTCL skin released greater numbers of T cells than normal skin; this was blocked by the addition of an IL-7 neutralizing antibody. Finally, these cultures induced proliferation of normal peripheral skin-homing T cells that were added to the cultures. These observations led us to postulate that IL-7 produced by skin cells contributes to the survival and proliferation of T cells within skin lesions and is likely the source of elevated circulating IL-7 in CTCL.

beta-Arrestin2 regulates the differential response of cortical and trabecular bone to intermittent PTH in female mice

Cytoplasmic arrestins regulate PTH signaling in vitro. We show that female beta-arrestin2(-/-) mice have decreased bone mass and altered bone architecture. The effects of intermittent PTH administration on bone microarchitecture differed in beta-arrestin2(-/-) and wildtype mice. These data indicate that arrestin-mediated regulation of intracellular signaling contributes to the differential effects of PTH at endosteal and periosteal bone surfaces.

INTRODUCTION

The effects of PTH differ at endosteal and periosteal surfaces, suggesting that PTH activity in these compartments may depend on some yet unidentified mechanism(s) of regulation. The action of PTH in bone is mediated primarily by intracellular cAMP, and the cytoplasmic molecule beta-arrestin2 plays a central role in this signaling regulation. Thus, we hypothesized that arrestins would modulate the effects of PTH on bone in vivo.

MATERIALS AND METHODS

We used pDXA, muCT, histomorphometry, and serum markers of bone turnover to assess the skeletal response to intermittent PTH (0, 20, 40, or 80 mug/kg/day) in adult female mice null for beta-arrestin2 (beta-arr2(-/-)) and wildtype (WT) littermates (7-11/group).

RESULTS AND CONCLUSIONS

beta-arr2(-/-) mice had significantly lower total body BMD, trabecular bone volume fraction (BV/TV), and femoral cross-sectional area compared with WT. In WT females, PTH increased total body BMD, trabecular bone parameters, and cortical thickness, with a trend toward decreased midfemoral medullary area. In beta-arr2(-/-) mice, PTH not only improved total body BMD, trabecular bone architecture, and cortical thickness, but also dose-dependently increased femoral cross-sectional area and medullary area. Histomorphometry showed that PTH-stimulated periosteal bone formation was 2-fold higher in beta-arr2(-/-) compared with WT. Osteocalcin levels were significantly lower in beta-arr2(-/-) mice, but increased dose-dependently with PTH in both beta-arr2(-/-) and WT. In contrast, whereas the resorption marker TRACP5B increased dose-dependently in WT, 20-80 mug/kg/day of PTH was equipotent with regard to stimulation of TRACP5B in beta-arr2(-/-). In summary, beta-arrestin2 plays an important role in bone mass acquisition and remodeling. In estrogen-replete female mice, the ability of intermittent PTH to stimulate periosteal bone apposition and endosteal resorption is inhibited by arrestins. We therefore infer that arrestin-mediated regulation of intracellular signaling contributes to the differential effects of PTH on cancellous and cortical bone.

Bone response to intermittent parathyroid hormone is altered in mice null for {beta}-Arrestin2

Intermittent PTH administration increases bone turnover, resulting in net anabolic effects on bone. These effects are primarily mediated by intracellular cAMP signaling. However, the molecular mechanisms that regulate PTH activity in bone remain incompletely understood. beta-Arrestin2, a G protein-coupled receptor regulatory protein, inhibits PTH-stimulated cAMP accumulation in vitro. Using beta-arrestin2(-/-) (KO) and wild-type (WT) mice, we investigated the response to PTH in primary osteoblasts (POB) and the effects of intermittent PTH administration on bone mass and microarchitecture in vivo. Compared with that in WT mice, PTH-stimulated intracellular cAMP was increased and sustained in KO POB. Intermittent exposure of POB to PTH significantly decreased the ratio of osteoprotegerin (OPG) receptor activator of nuclear factor-kappaB ligand (RANKL) mRNA expression in KO POB, whereas it increased this ratio in WT POB. Total body bone mass and cortical and trabecular bone parameters were 5-10% lower in male KO mice compared with WT, and these differences were magnified upon in vivo administration of intermittent PTH (80 mug/kg.d) for 1 month. Thus, PTH significantly increased total body bone mineral content as well as vertebral trabecular bone volume and thickness in WT, but not KO mice. The anabolic response to PTH in cortical bone was also slightly more pronounced in WT than KO mice. Histomorphometry indicated that PTH prominently stimulated indexes of bone formation in both WT and KO mice, whereas it significantly increased indexes of bone resorption (i.e. osteoclast number and surface) in KO mice only. In conclusion, these results suggest that beta-arrestins may specify the activity of intermittent PTH on the skeleton by limiting PTH-induced osteoclastogenesis.