Unintentional weight loss, obesity, and use of vitamin K antagonists (VKA) are among the risk factors for calciphylaxis in patients on hemodialysis (HD), according to new study findings from a case-control study published in BMC Nephrology.
Raphaël Gaisne, MD, of Nantes University Hospital Center in France, and colleagues studied the records of 89 patients with calciphylaxis—also called calcific uremic arteriolopathy (CUA). The group included 19 patients with chronic kidney disease not on dialysis and 70 patients on HD. “We were surprised to identify so many non-dialyzed patients with calciphylaxis,” the investigators related.
Dr Gaisne’s team matched each HD patient to 2 HD controls by age, sex, time period, and region of treatment. Two-thirds of patients had a triggering event such as local trauma or hypovolemia. Each patient displayed a median 5 lesions mostly on the lower limbs or trunk.
More than half of patients were obese and 71.9% were taking VKAs. Inflammation and bone mineral disease abnormalities (especially hyperphosphatemia and hyperparathyroidism), and malnutrition (eg, weight loss and serum albumin decrease) preceded calciphylaxis onset by 6 months.
In the HD patients with calciphylaxis, each 5 kg/m2 increase in body mass index was significantly associated with 56% increased odds of calciphylaxis compared with the HD control group. Each 1 kg of weight loss within 6 months of calciphylaxis diagnosis was significantly associated with 66% increased odds of calciphylaxis. HD patients with calciphylaxis were 5 times more likely than the control group to be using VKAs.
Multimodal treatment commonly involved wound care (98.9%), antibiotherapy (77.5%), discontinuation of VKA (70.8%), discontinuation of active vitamin D (70.0%), and intravenous sodium thiosulfate (STS, 65.2%).
Forty percent of patients died within a year of developing lesions, typically while receiving palliative care. Surgical debridement, distal CUA, localization to the lower limbs, and noncalcium-based phosphate binders were associated with better survival.
“Our study confirms the data reported by others on CUA but showed for the first time the contribution of significant unintentional weight loss,” Dr Gaisne’s team wrote. “Few therapeutic measures seem efficient. Among them, STS is commonly used, but its benefit has still to be proved.”
Calciphylaxis mainly involved obese patients on VKA therapy, the authors concluded. “Malnutrition and inflammation preceded the onset of skin lesions and could be warning signs among dialysis patients at risk.”
Gaisne R, Péré M, Menoyo V, et al. Calciphylaxis epidemiology, risk factors, treatment and survival among French chronic kidney disease patients: a case-control study [published online February 26]. BMC Nephrol. doi: 10.1186/s12882-020-01722-y