Calciphylaxis and nephrogenic fibrosing dermopathy with pseudoxanthoma elasticum‐like changes: Successful treatment with sodium thiosulfate

The Clinical Manifestations and Efficacy of Different Treatments Used for Nephrogenic Systemic Fibrosis: A Systematic Review

Aim

Nephrogenic systemic fibrosis (NSF) is a rare disorder that occurs in association majorly with chronic kidney disease (CKD). The lack of collective quantitative data on its clinical manifestations and the different treatment options' efficacy, call the need for our investigation.

Methods

A systematic review was conducted covering a timeline from inception up to July 2022 without any restrictions. Article screening and data extraction were performed independently on PubMed, Google Scholar, ScienceDirect, and Cochrane Library. The keywords that we used were CKD, NSF, Gadolinium enduced fibrosis, etc; shortlisted articles were assessed for risk of bias. Data were presented as frequencies and percentages, with a confidence interval of 95%. A chi-square test was also done to find significant relationships, with a p-value <0.05 considered significant.

Results

We had 83 patients in this review consisting of 44 (55.7%) females with a mean age of 51.4±14.6 years. Sixty-nine (83.1%) patients had chronic kidney disease predisposition to NSF. Previous exposure to gadolinium-based contrast dyes was seen in 66 (79.5%) patients). The most common symptom in patients was cutaneous lesions in 69 (83.1%) patients. The most used treatments were ultraviolet therapy, renal transplant, and extracorporeal photopheresis; in 13.3% of the patients each. Condition in most patients either improved (67.1%) or remained stable (11.8%). Chi-square testing found that the treatments offered were also seen to be significantly related to outcome (p=0.015).

Conclusion

The findings in this study provide a quantitative measurement of NSF's presentations and treatment efficacies. This serves to make way for researchers to form comprehensive guidelines on the presentation-based treatment of NSF.

Therapy of Pseudoxanthoma Elasticum: Current Knowledge and Future Perspectives

Pseudoxanthoma elasticum (PXE) is a rare, genetic, metabolic disease with an estimated prevalence of between 1 per 25,000 and 56,000. Its main hallmarks are characteristic skin lesions, development of choroidal neovascularization, and early-onset arterial calcification accompanied by a severe reduction in quality-of-life. Underlying the pathology are recessively transmitted pathogenic variants of the ABCC6 gene, which results in a deficiency of ABCC6 protein. This results in reduced levels of peripheral pyrophosphate, a strong inhibitor of peripheral calcification, but also dysregulation of blood lipids. Although various treatment options have emerged during the last 20 years, many are either already outdated or not yet ready to be applied generally. Clinical physicians often are left stranded while patients suffer from the consequences of outdated therapies, or feel unrecognized by their attending doctors who may feel uncertain about using new therapeutic approaches or not even know about them. In this review, we summarize the broad spectrum of treatment options for PXE, focusing on currently available clinical options, the latest research and development, and future perspectives.

Clinicopathologic Features and Calcium Deposition Patterns in Calciphylaxis: Comparison With Gangrene, Peripheral Artery Disease, Chronic Stasis, and Thrombotic Vasculopathy

Diagnosis of calciphylaxis is crucial, yet its distinction from other vascular diseases can be challenging. Although vascular calcification and thrombosis are hallmarks of calciphylaxis, the incidence and patterns of these features in other vascular diseases have not been well characterized. The specificity of fine calcium deposits in vessel walls (identifiable on von Kossa [VK] stain only) and other extravascular calcifications is not entirely clear. We retrospectively examined the clinicopathologic features in calciphylaxis (n=27), gangrene and viable skin at amputation margin (n=20 each), chronic stasis (n=22), and thrombotic vasculopathy (n=19) to identify useful discriminators. Calcification of subcutaneous small vessels appreciable on hematoxylin and eosin stain was relatively specific for calciphylaxis, although sensitivity was low (56%). VK detected fine calcium deposits in vessel walls not appreciable on hematoxylin and eosin, however, specificity was limited by frequent finding of similar deposits in peripheral artery disease. Combining calcium deposits detected by VK and thrombosis of subcutaneous small vessels resulted in optimal sensitivity (85%) and specificity (88%) for calciphylaxis. Similar observations applied to medium-sized vessel calcification. Calcification of eccrine gland basement membranes, elastic fibers, and perineurium did not effectively distinguish calciphylaxis from other groups. Diffuse dermal angiomatosis was exclusively found in calciphylaxis in this study. In conclusion, VK is useful in enhancing the detection of vascular calcification and avoiding the false-negative diagnosis, but this finding requires concomitant subcutaneous small vessel thrombosis to support a diagnosis of calciphylaxis. Diffuse dermal angiomatosis should increase suspicion for underlying calciphylaxis and prompt deeper sampling in the appropriate clinical setting.