Dermatologic Conditions Seen in End-Stage Renal Disease

Bradykinin's carbamylation as a mechanistic link to impaired wound healing in patients with kidney dysfunction

BACKGROUND

Uremic impairment of wound healing is a well-established phenomenon, however the etiology of this condition continues to be a medical enigma. Carbamylation, posttranslational modification (PTM) occurring with high frequency in uremic milieu, is known to have impact on structural and functional properties of proteins and peptides. Herein we show that carbamylation of the members of kinin-kallikrein system, that play an essential role in wound healing process, results in its aberrant functionality and impedes the complex process of tissue regeneration in uremic patients.

RESULTS

Through enzymatic assays we demonstrate that carbamylation of kininogen results in aberrant bradykinin generation. We confirmed that bradykinin is efficiently carbamylated in uremic conditions and, alternatively, by activated neutrophiles. Moreover, this modification affects proteolytic cleavage of the peptide, potentially leading to the accumulation of the carbamylated form. Modified peptide demonstrated lower affinity toward its receptors. Carbamylation diminished bradykinin's ability to stimulate expression of the B1 receptor and cytokines essential in wound healing process. Carbamylated bradykinin was significantly less potent in promoting angiogenesis and keratinocyte motility as compared to the native form. In the in vivo murine model of wound healing, we observed impaired collagen fiber production and delayed re-epithelialisation in the presence of carbamylated form.

CONCLUSIONS

Carbamylation-driven impairment of wound healing is a mechanistic link to wound persistence in uremia. Importantly, production of carbamylated bradykinin in localized inflammatory milieus could be a significant contributor to delayed wound healing and formation of chronic wounds in diabetes or psoriasis.

Renal Transplantation Could Reverse Dialysis-Associated Porphyria

Pseudoporphyria (PP) is a relatively infrequent, photodistributed bullous dermatosis that clinically, histopathologically, and immunologically resembles porphyria cutanea tarda (PCT), but is not accompanied by porphyrin abnormalities in the serum, urine, or stool. It was initially described in patients with renal failure on dialysis as 'bullous dermatosis of hemodialysis.' Pseudoporphyria has been seen in patients with end-stage renal disease on hemodialysis. No treatment has proved efficacious in the management of pseudoporphyria. However, N-acetylcysteine has been anecdotally reported to be effective in the management of hemodialysis-related pseudoporphyria and other porphyric diseases. Our patient had developed multiple skin lesions all over the body when hemodialysis started. The lesions were erythematous with fluid-filled vesicles, and bullae with cutaneous fragility that were evaluated and diagnosed as pseudoporphyria. The patient was treated with available all medication in the literature but was not relieved. However, all skin lesions completely healed within 22 days post renal transplantation. Renal transplantation proved to be the cure for dialysis-induced pseudoporphyria resistant to conventional drug therapy.

IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus

Uremic pruritus with elevated levels of calcium phosphate (CaP) in skin is a common symptom in patients with chronic kidney disease (CKD). In this study, we demonstrate that intradermal injection of CaP into mice triggered scratching by up-regulating the IL-6 in skin and phosphorylation of ERKs in dorsal root ganglion (DRG) in a dose-dependent manner. IL-6 is essential because the CaP-induced up-regulation of phosphorylated (p)-ERK in DRG was considerably reduced in the IL-6 knockout mice. Microarray analysis in conjunction with real-time PCR revealed a higher mRNA expression of Bruton's tyrosine kinase (BTK) gene in DRG after CaP injection. The inhibition of BTK by ibrutinib noticeably diminish the CaP-induced up-regulation of IL-6 and p-ERK in mice. A high amount of IL-6 was detected in itchy skin and blood of patients with CKD. The expressions of p-BTK and p-ERK in DRG primary cells reached maximum levels at 1 and 10 min, respectively, after treatment of recombinant IL-6 and were significantly reduced by treatment of IL-6 along with ibrutinib. The mechanism by which the CaP-induced pruritus mediated by the IL-6/p-BTK/p-ERK signaling was revealed.-Keshari, S., Sipayung, A. D., Hsieh, C.-C., Su, L.-J., Chiang, Y.-R., Chang, H.-C., Yang, W.-C., Chuang, T.-H., Chen, C.-L., Huang, C.-M. IL-6/p-BTK/p-ERK signaling mediates calcium phosphate-induced pruritus.

Dermatological manifestations in hemodialysis patients in Iran: A systematic review and meta-analysis

BACKGROUND

Dermatologic complications are common in patients with end-stage renal disease and also have a high diversity.

OBJECTIVES

This meta-analysis reviews prevalence of dermatological manifestations among hemodialysis patients in Iran.

MATERIALS AND METHODS

Using PubMed and NLM Gateway (for MEDLINE), Institute of Scientific Information (ISI), and SCOPUS as the main international electronic data sources, and Iran-Medex, Irandoc, and Scientific Information Database, as the main domestic databases with systematic search capability, we systematically searched surveys, papers, and reports on the prevalence of dermatological manifestations (until February 2016). Heterogeneity of reported prevalence's between studies was assessed using the Q test; overall prevalence of dermatological manifestations was estimated using random-effect meta-analysis model.

RESULTS

We found 1229 records; from them, a total of eight studies comprising 917 hemodialysis patients were included. In all of studies, skin discoloration, pruritus and xerosis have the highest prevalence. According to random-effect meta-analysis model, the pooled prevalence of skin discoloration, pruritus, ecchymosis, xerosis, and half-and-half nail in hemodialysis patients were 48.03% (95% CI: 45.09-51.01), 52.85% (95%CI: 49.23-56.47), 19.88 (95% CI: 17.57-22.19), 51.14% (95% CI: 48.25-54.02), and 18.50% (95% CI: 16.0-21.0), respectively.

CONCLUSIONS

his study shows that the prevalence of dermatological manifestations seems high among the hemodialysis patients in Iran, and skin discoloration, pruritus, and xerosis are more common.

Inflammatory Cutaneous Diseases in Renal Transplant Recipients

Kidney transplant recipients frequently suffer from skin infections and malignancies, possibly due to the effects of long-term immunosuppressive therapy. While the relationships between immunosuppression and these pathological conditions have been widely investigated, little is known about the relative incidence and characteristics of inflammatory skin diseases in this type of patient. In this study, we analyze the incidence of a number of inflammatory cutaneous diseases in a cohort of patients who underwent kidney transplantation. Although our study shows a relatively low incidence of these pathologies in transplanted patients-in agreement with the general action of immunosuppressant therapies in reducing inflammation-we scored a different efficacy of the various immunosuppressive regimens on inflammatory and autoimmune skin diseases. This information can be key for designing immunosuppressive regimens and devising accurate follow-up protocols.

[Porphyrias and haem related disorders]

The hereditary porphyrias comprise a group of eight metabolic disorders of the haem biosynthesis pathway characterised by acute neurovisceral symptoms, skin lesions or both. Each porphyria is caused by abnormal function of a separate enzymatic step resulting in a specific accumulation of haem precursors. Seven porphyrias are the consequence of a partial enzyme deficiency while a gain of function mechanism has been recently characterised in a novel porphyria. Acute porphyrias present with severe abdominal pain, nausea, constipation, confusion and seizure, which may be life threatening. Cutaneous porphyrias can be present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe chronic neurological symptoms or chronic haemolysis and severe cutaneous photosensitivity. Porphyrias are still underdiagnosed, but once they are suspected, and depending on the clinical presentation, a specific and simple front line test allows the diagnosis in all symptomatic patients. Diagnosis is essential to institute as soon as possible a specific treatment. Screening families to identify presymptomatic carriers is crucial to prevent chronic complications and overt disease by counselling on avoiding potential precipitants.

Cutaneous manifestations in patients with chronic renal failure on hemodialysis

Patients with chronic renal failure (CRF) may exhibit various cutaneous abnormalities, including changes in skin colour, pruritus, xerosis, hair, nail and oral changes, metastatic calcinosis, and bullous dermatosis. These changes have a considerable negative effect on the patient's quality of life. Early recognition of cutaneous signs and prompt initiation of treatment can dramatically alter their course and decrease morbidity.

Diagnosis of common dermopathies in dialysis patients: a review and update

Cutaneous abnormalities in patients with end-stage renal disease (ESRD) receiving hemodialysis or peritoneal dialysis may demonstrate signs of their underlying condition or reveal associated disease entities. While a thorough examination of the scalp, skin, mucosa, and nails is integral to establishing a diagnosis, certain conditions will resolve only with dialysis or improvement of their renal disease and others may not require or respond to treatment. Half and half nails, pruritus, xerosis, and cutaneous hyperpigmentation are common manifestations in ESRD. With hemodialysis, uremic frost is no longer prevalent in ESRD patients and ecchymoses have decreased in incidence. Acquired perforating dermatoses are seen in over one-tenth of hemodialysis patients. Metastatic calcinosis cutis and calciphylaxis are both rarely reported, although the latter is seen almost exclusively in the setting of hemodialysis. Diagnosis of nephrogenic systemic fibrosis has historically been challenging; as such, new diagnostic criteria have been proposed. Blood porphyrin profiles are needed to differentiate between porphyria cutanea tarda and pseudoporphyria. We will review and provide an update on the aforementioned common cutaneous manifestations of ESRD in patients receiving dialysis.

Nephrogenic systemic fibrosis: concepts and perspectives

Nephrogenic systemic fibrosis is a chronic, progressive condition that develops in some patients with renal impairment after exposure to gadolinium-based contrast agents used in magnetic resonance imaging. Thickening of the skin is typical, usually affecting the extremities. Visceral organs can also be affected. The diagnosis of the disease requires careful clinicopathological correlation. Treatment aims at restoring renal function, which is associated with delayed progression and, eventually, remission of skin changes. Reduction and prevention of nephrogenic systemic fibrosis cases are based on limiting the use of gadolinium-based contrast agents in patients with kidney disorders (especially in patients with advanced renal failure at stages 4 and 5), and restricting their use to situations in which they are essential to diagnosis/follow-up. Other than limiting exposure to gadolinium based contrast agents, no effective preventive methods have been reported. Due to increased awareness about the disease among radiologists and nephrologists, the incidence of nephrogenic systemic fibrosis is declining.

Iatrogenic hyperadrenocorticism, calcinosis cutis, and myocardial infarction in a dog treated for IMT

An 8 yr old male English bulldog receiving treatment for immune-mediated thrombocytopenia was diagnosed with calcinosis cutis 90 days after initiation of corticosteroid therapy. Twenty-four days later, the patient presented in a comatose state after collapsing and was euthanized. Postmortem examination revealed coronary arteriosclerosis and myocardial infarction leading to congestive heart failure. Calcinosis cutis and myocardial necrosis were most likely complications associated with administration of corticosteroids in this dog. Important implications regarding the classification of calcinosis cutis and the use of immunosuppressive doses of corticosteroids are discussed.

Secondary hyperparathyroidism: Uncommon cause of a leg ulcer

INTRODUCTION

Most leg ulcers are vascular based. Only if vascular therapy fails other causes are considered. We report the case of a female with incapacitating leg ulcers caused by a rare condition which was only diagnosed after failing treatment.

PRESENTATION OF CASE

The female had an extensive previous history including diabetes, renal insufficiency and cardiovascular disease and presented with three large and painful ulcers on her left lower leg. Standard treatment with antibiotics, wound excision and additional treatment with hyperbaric oxygen were ineffective. One month post hospital-admission calciphylaxis cutis caused by renal failure induced secondary hyperparathyroidism was diagnosed. Surgical treatment by a parathyroidectomy induced rapid regeneration of the ulcers.

DISCUSSION

Our patient's vast comorbidity and previous history had expanded differential considerations causing a delay in diagnosis. Our patient's previous history led us to believe her ulcers were vascular based, however her chronic renal failure appeared responsible for her condition.

CONCLUSION

Although less probable than venous insufficiency and concomittant leg ulcers or other differential considerations, calciphylaxis cutis should be part of the differential diagnosis in any end stage renal disease-patient with unexplained ulcers as an effective therapy is readily available.

Cutaneous manifestations in end-stage renal disease

The prevalence of chronic kidney disease has increased over the last years. The effects of this disease are complex and may lead to dysfunction of multiple organs, including the skin, with most patients presenting with at least one dermatologic alteration. Sometimes these symptoms can be the first clear sign of kidney disease. This article discusses the skin manifestations related to severe renal impairment or end-stage renal disease (ESRD), which are divided into nonspecific and specific, and reviews the clinical features, etiopathogenesis and therapeutic options for these dermatoses. Early recognition and treatment reduce morbidity and improve these patients' quality of life.

Case for diagnosis

Acquired perforating dermatosis is a rare condition often associated with some systemic diseases, especially diabetic patients with chronic renal failure undergoing dialysis. The main symptom is pruritus and it is clinically characterized by the presence of redish-brown papular lesions in the trunk, head and neck. Biopsy of the lesion reveals epidermal invagination with keratotic plug. The etiology is poorly understood and several therapeutic measures have been disappointing.

Bullous skin lesions in a patient undergoing chronic hemodialysis

Porphyria cutanea tarda (PCT) is a vesiculobullous skin disorder characterized by a defect in heme biosynthesis. Reduced activity of the hepatic enzyme uroporphyrinogen decarboxylase (URO-D) results in accumulation of photosensitive porphyrins; this ultimately leads to the skin fragility and blistering that is characteristic of this disease. The majority of cases of PCT are associated with acquired deficiencies of the enzyme URO-D, secondary to hepatic injury precipitated by medications or infections. Less commonly, PCT has been documented in patients with end-stage renal disease. The pathogenesis of PCT in long-term hemodialysis (HD) has been attributed to many factors, but the following mechanisms have been implicated: (i) decreased hepatic URO-D activity due to suppressive effects of iron and other hepatotoxins and (ii) poor porphyrin clearance by renal replacement therapies. We report a case of PCT that developed in a patient on maintenance HD for 4 years. He had a history of hepatitis C and evidence of iron overload. However, as the patient was anemic, therapeutic phlebotomy was problematic and therefore erythrocyte-stimulating agents were maximized to mobilize iron stores and allow phlebotomy. With this treatment, the patient's skin lesions improved in conjunction with decreasing ferritin levels.

Porphyrias

Hereditary porphyrias are a group of eight metabolic disorders of the haem biosynthesis pathway that are characterised by acute neurovisceral symptoms, skin lesions, or both. Every porphyria is caused by abnormal function of a separate enzymatic step, resulting in a specific accumulation of haem precursors. Seven porphyrias are the result of a partial enzyme deficiency, and a gain of function mechanism has been characterised in a new porphyria. Acute porphyrias present with acute attacks, typically consisting of severe abdominal pain, nausea, constipation, confusion, and seizure, and can be life-threatening. Cutaneous porphyrias present with either acute painful photosensitivity or skin fragility and blisters. Rare recessive porphyrias usually manifest in early childhood with either severe cutaneous photosensitivity and chronic haemolysis or chronic neurological symptoms with or without photosensitivity. Porphyrias are still underdiagnosed, but when they are suspected, and dependent on clinical presentation, simple first-line tests can be used to establish the diagnosis in all symptomatic patients. Diagnosis is essential to enable specific treatments to be started as soon as possible. Screening of families to identify presymptomatic carriers is crucial to decrease risk of overt disease of acute porphyrias through counselling about avoidance of potential precipitants.