Calciphylaxis: the beginning of the end?
BACKGROUND
We previously reported a very high incidence of calciphylaxis, mainly in peritoneal dialysis (PD) patients. Although we identified several risk factors for the condition, including PD, we were unable to identify why our particular unit had such a high frequency of the condition and a reliable treatment.


OBJECTIVE
To assess the apparent changing frequency of the condition and the response to therapy, and to attempt to determine putative factors that might explain our uniquely high incidence of calciphylaxis.


METHODS
A prospective clinical record was kept on all patients that developed calciphylaxis in our center [both PD and hemodialysis (HD) units] between 1998 and 2006.


RESULTS
Of the 59 patients that developed calciphylaxis, 54 were on PD, 4 were on HD, and 1 was in predialysis. In the PD population, the mean yearly incidence from 1998 to 2003 was 4.5/100 patient-years, falling to 1.3/100 patient-years in 2004-2006. The percent of patients not taking calcium salts fell during this time period. Conversion to HD led to marked early improvement. A marked discrepancy between the levels of ionized calcium (routinely used in our center) and corrected serum calcium was found, with most cases of hypercalcemia (corrected) being missed by using ionized values.


CONCLUSIONS
The incidence of calciphylaxis is falling dramatically. This may be related partially to reduction in usage of calcium salts. Conversion to HD is beneficial. Our uniquely high incidence of calciphylaxis may be related to our use of ionized calcium levels to monitor these patients.
Fine
Adrian
A
Section of Nephrology, University of Manitoba, Winnipeg, Manitoba, Canada. dr_adrian_fine@yahoo.ca
Fontaine
Bunny
B
D002115:Calciphylaxis / Q000453:epidemiology / Q000209:etiology* / Q000628:therapy; D002118:Calcium / Q000008:administration & dosage / Q000009:adverse effects*; D002119:Calcium Carbonate / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000453:epidemiology / Q000628:therapy; D008350:Manitoba / Q000453:epidemiology; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010538:Peritonitis / Q000453:epidemiology / Q000209:etiology; D015995:Prevalence; D006435:Renal Dialysis; D012307:Risk Factors
D002119:Calcium Carbonate; D002118:Calcium