A case of systemic pseudo-pseudoxanthoma elasticum with diverse symptomatology caused by long-term penicillamine use

ABCC6, Pyrophosphate and Ectopic Calcification: Therapeutic Solutions

Pathological (ectopic) mineralization of soft tissues occurs during aging, in several common conditions such as diabetes, hypercholesterolemia, and renal failure and in certain genetic disorders. Pseudoxanthoma elasticum (PXE), a multi-organ disease affecting dermal, ocular, and cardiovascular tissues, is a model for ectopic mineralization disorders. ABCC6 dysfunction is the primary cause of PXE, but also some cases of generalized arterial calcification of infancy (GACI). ABCC6 deficiency in mice underlies an inducible dystrophic cardiac calcification phenotype (DCC). These calcification diseases are part of a spectrum of mineralization disorders that also includes Calcification of Joints and Arteries (CALJA). Since the identification of ABCC6 as the “PXE gene” and the development of several animal models (mice, rat, and zebrafish), there has been significant progress in our understanding of the molecular genetics, the clinical phenotypes, and pathogenesis of these diseases, which share similarities with more common conditions with abnormal calcification. ABCC6 facilitates the cellular efflux of ATP, which is rapidly converted into inorganic pyrophosphate (PPi) and adenosine by the ectonucleotidases NPP1 and CD73 (NT5E). PPi is a potent endogenous inhibitor of calcification, whereas adenosine indirectly contributes to calcification inhibition by suppressing the synthesis of tissue non-specific alkaline phosphatase (TNAP). At present, therapies only exist to alleviate symptoms for both PXE and GACI; however, extensive studies have resulted in several novel approaches to treating PXE and GACI. This review seeks to summarize the role of ABCC6 in ectopic calcification in PXE and other calcification disorders, and discuss therapeutic strategies targeting various proteins in the pathway (ABCC6, NPP1, and TNAP) and direct inhibition of calcification via supplementation by various compounds.

Pediatric Pseudo-pseudoxanthoma Elasticum Resulting From D-Penicillamine Treatment for Wilson Disease

We describe a 14-year-old boy with Wilson disease (WD) who first developed pseudo-pseudoxanthoma elasticum (PPXE) after 4.5 years of treatment with D-penicillamine. Although previously reported cases have occurred in adults following at least a decade of high-dose D-penicillamine use, this case demonstrates that D-penicillamine-induced PPXE can present in children with shorter treatment courses. Upon this diagnosis, the patient was switched from D-penicillamine to trientine, with adequate cupriuresis and stabilization of the skin lesion. Prompt diagnosis and management of PPXE in children can limit systemic progression and prevent long-term complications.

Elastoderma: Case Report and Literature Review

Elastoderma is a rare cutaneous condition, which clinically presents as an acquired laxity and decreased recoil of skin. It is histologically characterized by an increase of pleomorphic and fragmented elastic fibers in the superficial dermis. A case of a 61-year-old woman with wrinkled lax skin on the anterior and lateral aspects of her neck was reported. Microscopic examination revealed an accumulation of fragmented curled elastic fibers in the dermis. This is the fifth reported case of elastoderma.

Detection of D-penicillamine in skin lesions in a case of dermal elastosis after a previous long-term treatment for Wilson's disease

BACKGROUND

Skin adverse events associated with D-Penicillamine (DPA) are common and multi-faceted, although the presence of DPA or its metabolites has never been documented in the skin, because of inherent difficulties in determining its tissue levels. Thus, the association between DPA and DPA-related dermatoses has been only hypothesized on the basis of careful history, clinical observation and typical histopathological findings.

OBJECTIVE

To detect DPA in biopsy specimens in a unique case of 25-year-late-onset elastosis perforans serpiginosa and pseudo-pseudoxanthoma elasticum associated with a history of long-term high dose DPA, by applying a recently described analytical method to assess the presence of DPA in skin.

METHODS

We used a reliable analytical method based on high-performance liquid chromatography coupled with amperometric detection to look for the presence of DPA in skin biopsy specimens.

RESULTS

A chromatographic peak corresponding to DPA was evidenced in some affected skin samples collected from the patient.

CONCLUSION

We documented the effective presence and the persistence after 25 years of DPA in the skin of a woman affected by elastotic cutaneous change due to a long-term therapy with DPA. This report provides further evidence of the relationship between DPA deposit in affected skin and clinical manifestation.

Elastosis perforans serpiginosa in association with scabies mite

Elastosis perforans serpiginosa is a form of perforating dermatoses, which has a characteristic clinical presentation of grouped keratotic papules coalescing into serpiginous or annular configurations. The majority of elastosis perforans serpiginosa cases are idiopathic; however, various etiologies have been postulated for the pathogenesis of this syndrome. The authors present a unique case of elastosis perforans serpiginosa that developed focally secondary to a scabies mite.

Cystic kidney disease in a patient with systemic toxicity from long-term D-penicillamine use

D-penicillamine, used to treat cystinuria, is known to cause impaired collagen deposition and dysfunction in elastic fibers. D-penicillamine also has been associated with glomerular abnormalities, typically membranous glomerulonephritis. We describe a patient with severe bilateral cystic kidney disease that developed after long-term D-penicillamine use for treatment of cystinuria. The cysts in the kidneys were noted during an evaluation for acute kidney injury. The patient had no evidence of cysts on prior renal imaging at a time when his kidney function was normal. Simultaneously, he presented with multiorgan manifestations of D-penicillamine toxicity, including the skin findings of cutix laxa and elastosis perforans serpiginosa. Consequently, D-penicillamine treatment was discontinued, after which the progression of cystic kidney disease gradually ceased, along with the other systemic manifestations of toxicity. To our knowledge, this is the first report of cystic kidney disease associated with and perhaps caused by long-term d-penicillamine therapy. The proposed mechanism of cyst formation is the malfunction of the extracellular matrix of the kidney by d-penicillamine that leads to an impaired repair process after kidney injury.

Penicillamine revisited: historic overview and review of the clinical uses and cutaneous adverse effects

Penicillamine is a well-known heavy metal chelator, classically used in the treatment of Wilson disease, rheumatoid arthritis, and cystinuria. From a dermatologic standpoint, penicillamine was found to be useful in the treatment of systemic sclerosis. The successful therapeutic uses of penicillamine have been hindered by its numerous adverse effects, both cutaneous and extra-cutaneous. It is a unique drug since it provokes a diversity of dermatologic manifestations that include (1) acute hypersensitivity reactions, (2) dermopathies characterized by elastic fiber abnormalities including elastosis perforans serpiginosa and pseudo-pseudoxanthoma elasticum, (3) autoimmune disorders such as pemphigus and penicillamine-induced lupus erythematosus-like syndrome, and (4) miscellaneous dermatoses that result from undefined mechanisms. These cutaneous adverse effects may correlate with the dosage and duration of penicillamine therapy as well as the disease being treated.

Acquired Pseudoxanthoma elasticum-like syndrome in beta-thalassaemia patients

A significant number of patients diagnosed with beta-thalassaemia develop clinical and histopathological manifestations similar to those of an inherited disorder called Pseudoxanthoma elasticum (PXE). The inherited PXE is caused by mutations in the ATP-binding cassette, subfamily C (CFTR/MRP), member 6 (ABCC6) gene and is characterized by mineralized elastic fibres in dermal, vascular and ocular tissues. As no disease-causing variant was found in the ABCC6 gene of 10 beta-thalassaemia patients with a PXE-like phenotype, the present study suggests that the PXE-like symptoms in these beta-thalassaemic patients are not related to ABCC6 mutations.

Clinical and histological spectrum of elastotic changes induced by penicillamine

A 79-year-old-man with cystinuria requiring long-term penicillamine therapy presented with a 6-month history of itchy annular lesions in both axillae. Clinical examination revealed lesions consisting of crusted keratotic papules coalescing in an annular distribution. Associated findings included generalized skin laxity accentuated on the upper trunk and arms, as well as small yellowish papules on the neck. Histological evaluation revealed short, thick, eosinophilic elastic fibres with nodular protrusions. Transepidermal elimination of abnormal elastic fibres was also evident. We discuss the histological and clinical spectrum of penicillamine-induced elastotic changes and compare these changes to those seen in primary elastotic disorders.

Pseudoxanthoma Elasticum Masquerading as Sjögren’s Syndrome

Pseudoxanthoma elasticum is an inherited disorder of abnormal calcification of elastic fibers in the skin, retina, and cardiovascular system. Herein, we report a patient who had dry eyes and mouth, keratoconjunctivitis sicca, and a low titer ANA at presentation. A lip biopsy was performed to confirm a clinical suspicion of Sjögren's syndrome; however, the histologic findings were diagnostic of pseudoxanthoma elasticum. Antibodies to Ro and La were negative. Subsequently, she was found to have skin and eye findings consistent with pseudoxanthoma elasticum. Although a causal relationship between keratoconjunctivitis sicca and pseudoxanthoma elasticum is not proven, salivary gland involvement with pseudoxanthoma elasticum may explain this patient's symptoms. Physicians should consider the diagnosis of pseudoxanthoma elasticum in patients who present with sicca symptoms without obvious cause, especially if cutaneous or ophthalmologic abnormalities, or both, are present. Careful monitoring for associated problems is needed as soon as pseudoxanthoma elasticum is diagnosed.