Calcific uremic arteriolopathy (CUA), also called calciphylaxis, is a rare but severe condition predominantly affecting patients with advanced chronic kidney disease (CKD). The disorder is characterized by calcification of small arterioles, ischemia, and painful skin lesions. The etiology and pathomechanisms remain incompletely understood. This review aimed to identify clinical, biochemical, and pathologic factors associated with CUA by synthesizing comparative studies that evaluated CKD patients with and without CUA.
The authors searched EMBASE and PubMed through February 2026 for studies permitting direct comparisons between CKD patients who developed CUA and those who did not. From 2,374 screened records, 35 publications met the inclusion criteria and were analyzed. The review focused on reported associations between CUA and demographic factors, comorbidities, laboratory markers, dialysis modality and adequacy, medication exposures, and histopathologic findings.
Across the included studies, several factors emerged repeatedly as associated with CUA. Decreased serum albumin and elevated alkaline phosphatase were consistent laboratory correlates. Clinical factors that consistently appeared were diabetes mellitus, increased body mass index, and female sex. Medication exposure to vitamin K antagonists (VKA)—for example, warfarin—was also consistently linked to CUA in the reviewed literature. Higher calcium–phosphate product and the presence of vascular calcification and thrombosis in subcutaneous small arteries were pathologic or biochemical features commonly reported in association with CUA.
The review identified additional factors that appeared likely to be associated with CUA but were less consistently reported across studies. These included anemia, indicators of suboptimal dialysis efficiency, and peritoneal dialysis modality. Systemic inflammation, arterial hypertension, cigarette smoking, and hepatobiliary disease also featured as possible contributors in multiple reports. The authors emphasize that these associations were variable and may reflect differences in study design, sample size, and patient populations across the literature.
Histopathologic descriptions in the literature commonly document medial and intimal calcification of small subcutaneous arterioles with associated thrombosis and tissue ischemia. Biochemical abnormalities that were repeatedly associated with CUA include disturbances in mineral metabolism, notably elevated calcium–phosphate product and higher alkaline phosphatase. The review highlights that calcification combined with thrombosis in small subcutaneous vessels is a recurring finding in patients with CUA.
Several parameters showed inconsistent or ambiguous relationships with CUA in the analyzed studies. Alterations in matrix Gla protein, a vitamin K–dependent inhibitor of vascular calcification implicated in mediating VKA effects, yielded mixed findings across reports. Parathyroid hormone (PTH) levels and evidence for a hypercoagulable state were also reported inconsistently. These ambiguities limit firm conclusions about causal or mediating roles for these factors based on the current comparative literature.
The review identifies important methodological limitations in the published literature. One notable gap is the absence of a standardized system for CUA skin biopsy evaluation, which hampers cross-study comparison of histologic features. Variability in study designs, small sample sizes for a rare condition, and heterogeneous reporting of laboratory and clinical variables further restrict the ability to draw definitive causal inferences.
This systematic review delineates major risk factors and pathogenic parameters associated with calciphylaxis in CKD. Consistent associations include low albumin, higher alkaline phosphatase, diabetes, increased BMI, female sex, VKA use, elevated calcium–phosphate product, and subcutaneous small-artery calcification with thrombosis. Several additional factors—anemia, reduced dialysis adequacy, peritoneal dialysis, inflammation, hypertension, smoking, and hepatobiliary disease—appear likely but require more robust confirmation.
The authors underscore that robust mechanistic data are still lacking for several hypothesized pathways, including the role of matrix Gla protein, PTH regulation, and coagulation abnormalities. They highlight the need for standardized histopathologic criteria for skin biopsy assessment and for well-designed studies to clarify causal pathways. Improved understanding of these mechanisms could support earlier identification of at-risk patients and inform preventive or therapeutic strategies in CKD populations.