Markedly elevated alpha-fetoprotein and positive acetylcholinesterase in amniotic fluid from a pregnancy affected with dystrophic epidermolysis bullosa

Fetal and Placental Causes of Elevated Serum Alpha-Fetoprotein Levels in Pregnant Women

The most common association related to alpha-fetoprotein (AFP) is fetal neural tube defect (NTD), and indeed, this is where the international career of this protein began. In times when ultrasonography was not yet technically advanced, the detection of high levels of AFP in maternal serum (MS-AFP) and amniotic fluid was the basis for suspecting neural tube defects. In cases where there was no confirmation of NTD, other causes were sought. It has been established that high titers of MS-AFP could originate in other defects or diseases, such as (1) increased proteinuria in severe fetal kidney diseases; (2) pathological overproduction in liver diseases; (3) penetration through the membranes of gastrointestinal organs exposed to amniotic fluid; (4) passage through the walls of skin vessels; and as a side effect of (5) hepatic hematopoiesis and increased transfer through the edematous placenta in fetal anemia. This article provides a review of the current literature on congenital defects and genetic diseases in the fetus where an elevated level of MS-AFP may serve as the initial diagnostic clue for their detection.

Neuronal Control of Skin Function: The Skin as a Neuroimmunoendocrine Organ

This review focuses on the role of the peripheral nervous system in cutaneous biology and disease. During the last few years, a modern concept of an interactive network between cutaneous nerves, the neuroendocrine axis, and the immune system has been established. We learned that neurocutaneous interactions influence a variety of physiological and pathophysiological functions, including cell growth, immunity, inflammation, pruritus, and wound healing. This interaction is mediated by primary afferent as well as autonomic nerves, which release neuromediators and activate specific receptors on many target cells in the skin. A dense network of sensory nerves releases neuropeptides, thereby modulating inflammation, cell growth, and the immune responses in the skin. Neurotrophic factors, in addition to regulating nerve growth, participate in many properties of skin function. The skin expresses a variety of neurohormone receptors coupled to heterotrimeric G proteins that are tightly involved in skin homeostasis and inflammation. This neurohormone-receptor interaction is modulated by endopeptidases, which are able to terminate neuropeptide-induced inflammatory or immune responses. Neuronal proteinase-activated receptors or transient receptor potential ion channels are recently described receptors that may have been important in regulating neurogenic inflammation, pain, and pruritus. Together, a close multidirectional interaction between neuromediators, high-affinity receptors, and regulatory proteases is critically involved to maintain tissue integrity and regulate inflammatory responses in the skin. A deeper understanding of cutaneous neuroimmunoendocrinology may help to develop new strategies for the treatment of several skin diseases.

Cholinergic control of epidermal cohesion

The non-neuronal cholinergic system of human epidermis includes the keratinocyte (KC) acetylcholine (ACh) axis composed of the enzymes mediating ACh synthesis and degradation, and two classes of ACh receptors, the nicotinic and muscarinic ACh receptors, mediating biological effects of the cutaneous cytotransmitter ACh. Regulation of KC cell-cell and cell-matrix adhesion is one of the important biological functions of cutaneous ACh. The downstream targets of ACh effects mediated by distinct ACh receptor subtypes include both the intercellular adhesion molecules, such as classical and desmosomal cadherins, and integrins mediating KC adhesion to a substrate. The signaling pathways include activation or inhibition of kinase cascades resulting in either up- or down-regulation of the expression of cell adhesion molecules or changes in their phosphorylation status, or both. The components of the KC ACh axis are involved in cutaneous blistering in patients with autoimmune pemphigus, junctional and dystrophic forms of epidermolysis bullosa, thermal burns, and mustard-induced vesication. Recent progress with the development of antiacantholytic therapies of patients with pemphigus using cholinomimetics indicates that cholinergic drugs may be a promising approach for other cutaneous blistering disorders.