Total Calcium and Albumin Are Decreased in the Deeper Epidermis of Patients with Chronic Kidney Disease-Associated Pruritus.
OBJECTIVE
In our earlier studies, we reported high concentrations of intra- and extracellular calcium ions (Ca2+) in the deeper epidermis of patients with chronic kidney disease (CKD) and associated pruritus. To determine the cause of this phenomenon, we measured total calcium (TCa) concentrations in the deeper epidermis and performed immunostaining of epidermal albumin, which binds to Ca2+.


METHODS
This study included 45 patients with CKD-stage 5, which was defined as severely reduced kidney function (i.e., estimated glomerular filtration rate less than 15 mL/min or on dialysis). Subjects were divided into the pruritus group, consisting of patients with mild, moderate, or severe uremic pruritus, and the non-pruritus group, consisting of patients with no or slight pruritus. The particle-induced X-ray emission method was used to measure elements including TCa. Furthermore, we have immunostained epidermal albumin using anti-albumin antibodies and compared the results in the pruritus and non-pruritus groups.


RESULTS
The TCa concentration in the spinous layer of patients with CKD with CKD-associated pruritus was lower than in patients with CKD without pruritus (median [range], 395 [235-1,063] vs. 476 [342-1,243] μg/g). The intensity of epidermal albumin expression in the spinous layer was weaker in patients with CKD with CKD-associated pruritus than in those without.


CONCLUSIONS
Patients with CKD with CKD-associated pruritus demonstrated higher Ca2+ concentrations but lower TCa concentrations than patients without CKD-associated pruritus. This could be in part due to low concentrations of epidermal albumin, which binds to Ca2+, in those with CKD-associated pruritus. These results clarify the pathophysiology of CKD-associated pruritus, providing a valuable foundation for the future development of treatments for this condition.
Department of Urology, Jusendo General Hospital, Koriyama, Japan.
Akishi
A
Momose
Yasuo
Y
Shiraiwa
Satoshi
S
Narita
Tomomi
T
Kusumi
Shoko
S
Goto
Koichiro
K
Sera
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004817:Epidermis / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007150:Immunohistochemistry; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000378:metabolism; D011537:Pruritus / Q000209:etiology* / Q000378:metabolism*; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000378:metabolism*; D014131:Trace Elements / Q000378:metabolism; D014511:Uremia / Q000150:complications / Q000378:metabolism
D000418:Albumins; D010281:Parathyroid Hormone; D014131:Trace Elements; D002118:Calcium
Albumin; Calcium; Chronic kidney disease-associated pruritus; Chronic renal failure