Modulation of peritoneal macrophage antimicrobial activity by peritoneal dialysis fluid, Ca++, and 1,25(OH)2D3 in CAPD patients.
Previous in vitro studies showed that Ca++ and 1,25(OH)2D3 modulate peritoneal macrophage (PM0) antimicrobial activity in CAPD patients. Twenty-four CAPD patients were evaluated in vivo (12 who had never had peritonitis, and 12 with an overall peritonitis incidence of more than one episode per 8 patient/months), for the effects of different peritoneal dialysis fluids (PDF) and Ca++ concentrations (1.25, 1.75, and 2.25 mmol/L) on PM0: cytoplasmic Ca++ concentration; superoxide generation; leukotriene B4 (LTB4) release; and bacterial killing for Staphylococcus epidermidis. The same parameters were also evaluated after adding 1,25(OH)2D3 (0.25 microgram/L) to the PDF. Results showed a direct correlation between the PDF Ca++ concentration and PM0 Ca++ levels, superoxide and LTB4 generation, and bacterial killing such that, with 2.25 mmol/L of Ca++, these values were significantly higher than those seen with 1.75 mmol/L. The addition of 1,25(OH)2D3 potentiated the Ca(++)-induced effects. On the other hand, with PDF Ca++ levels of 1,25 mmol/L, an inhibition of the aforementioned parameters was seen. However, this effect was reversed by the addition of 1,25(OH)2D3. These in vivo results confirm the importance of Ca++ and 1,25(OH)2D3 in PM0 antibacterial function in CAPD patients, and may be useful in determining the prophylaxis and therapy of peritonitis.
Carozzi
S
S
Nephrology and Dialysis Unit, St. Paul's Hospital, Savona, Italy.
Nasini
M G
MG
Schelotto
C
C
Caviglia
P M
PM
Barocci
S
S
Cantaluppi
A
A
Salit
M
M
D002117:Calcitriol / Q000008:administration & dosage*; D002118:Calcium / Q000008:administration & dosage* / Q000378:metabolism; D015314:Dialysis Solutions; D006801:Humans; D007676:Kidney Failure, Chronic / Q000276:immunology*; D007975:Leukotriene B4 / Q000378:metabolism; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D013212:Staphylococcus epidermidis / Q000276:immunology; D013481:Superoxides / Q000378:metabolism
D015314:Dialysis Solutions; D013481:Superoxides; D007975:Leukotriene B4; D002117:Calcitriol; D002118:Calcium