Angiokeratoma: decision-making aid for the diagnosis of Fabry disease.

Isolated angiokeratomas are common benign cutaneous lesions, generally deemed unworthy of further investigation. In contrast, diffuse angiokeratomas should alert the physician to a possible diagnosis of Fabry disease, a rare X-linked lysosomal storage disorder, characterized by α-galactosidase deficiency. Glycosphingolipids accumulate in cells throughout the body resulting in progressive multi-organ failure. Difficulties are encountered when trying to interpret the significance of angiokeratomas because they may also occur in other lysosomal storage disorders and rarely in an isolated manner in Fabry disease. We present an algorithm for the classification of angiokeratomas which might prove useful for the diagnosis and management of Fabry disease. Assessment of the clinical features and location of the lesions, personal and family history, skin biopsy, dermoscopy and electron microscopy imaging are sequential steps in the diagnostic process. Assessing the deficiency of α-galactosidase enzyme activity is essential to confirm the diagnosis in males, while mutation analysis is always needed in females. Potentially this algorithm can change the current approach to patients when Fabry disease is suspected, thus improving the diagnostic strategy and management of this disorder. It remains to be decided whether the use of an algorithm might reduce the number of genetic consultations. As evidence has shown the efficacy of enzyme replacement therapy in halting progression of the disease before the onset of irreversible organ damage, it is advisable to aim at an early diagnosis in order to achieve timely initiation of effective treatment with benefits for patients and appropriate use of medical resources.

Role of fibroblast-derived growth factors in regulating hyperpigmentation of solar lentigo.

BACKGROUND: Cutaneous pigmentation is regulated by a complex melanogenic network in which both keratinocytes and fibroblasts synthesize growth factors and cytokines. Solar lentigo (SL) is characterized by hyperpigmented lesions occurring on photodamaged skin areas. Despite the association of SL to ultraviolet (UV) exposure, the mechanisms underlying the development of these spots are not completely defined. OBJECTIVES: To analyse the involvement of the fibroblast-derived growth factors, hepatocyte growth factor (HGF), keratinocyte growth factor (KGF) and stem cell factor (SCF) in SL hyperpigmentation; to evaluate whether the photoageing process occurring in fibroblasts could be responsible for the altered expression of these cytokines; and to investigate a new possible role of KGF in regulating pigmentation through the specific induction of melanogenic cytokines by keratinocytes. METHODS: We performed immunohistochemical analysis of HGF, KGF and SCF on SL biopsies. We analysed the mRNA expression of these cytokines using an in vitro model of photoageing induced on fibroblasts. Finally, we evaluated the effects of KGF on the expression of melanogenic cytokines at the mRNA and protein levels on keratinocytes. RESULTS: We found positive staining for HGF, KGF and SCF in the upper dermis of SL lesions and a significant induction of the three cytokines in photoaged fibroblasts. We also demonstrated the contribution of KGF to pigmentation, showing its ability specifically to modulate the expression of SCF in keratinocytes. CONCLUSIONS: Fibroblasts may be persistently activated by UV exposure to release melanogenic growth factors; this inducible cytokine network acts both directly and indirectly through keratinocytes and may contribute to the hyperpigmentation of SL.

Co-localization of IgA and TG3 on healthy skin of coeliac patients.

BACKGROUND: Dermatitis herpetiformis (DH), the skin's expression of coeliac disease (CD), is induced by the presence of IgA antibodies and epidermal transglutaminase (TG3) as the main autoantigen, stored in the papillary dermis and on the vessel walls. AIMS: To evaluate the presence of IgA and TG3 deposits, considered to be the first step in inducing DH, in healthy skin of coeliac patients without cutaneous manifestations. METHODS: Punch biopsies were taken from 11 consecutive coeliac patients, two with DH and nine without cutaneous manifestations, three of whom were adhering to a gluten-free diet (GFD), and evaluated for the presence of deposits in the upper dermis and vessel walls by immunofluorescence and confocal microscopy. RESULTS: In coeliac patients affected by DH we found the presence of IgA and TG3 deposits mainly on the upper dermis, but also in vessel walls. In all coeliac patients without DH and also in those patients who were following a strict GFD, we found widely variable deposits of IgA and TG3 in both the papillary dermis and the vessel walls, although a lower intensity of the fluorescence signal was detected than with coeliac patients affected by DH. Double immunostaining with anti-IgA and anti-TG3 antibodies showed a strong co-localization in the upper dermis in patients with DH and a weaker co-localization in those without DH. CONCLUSIONS: We have demonstrated the presence of IgA and TG3 deposits in the healthy skin of coeliac patients, which are considered to play a central role in the pathogenesis of DH.