Peritoneal dialysis fluid (PDF) C++ and 1,25(OH)2D3 modulate peritoneal macrophage (PM0) antimicrobial activity in CAPD patients.
Our previous in vitro studies have shown that Ca++ and 1,25(OH)2D3 modulate peritoneal macrophage (PMO) antimicrobial activity in CAPD patients. We thus evaluated in vivo in 24 CAPD patients (12 who had never had peritonitis and 12 with an overall peritonitis incidence of more than one episode per 8 patient/month), the effects of different peritoneal dialysis fluid (PDF) Ca++ concentrations (1.25, 1.75 and 2.25 mmol/L) on PMO: 1. cytoplasmic Ca++ concentration; 2. superoxide generation; 3. Leukotriene B4 (LTB4) release; 4. 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 PMO 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 contrary, 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 PMO antibacterial functions in CAPD patients and may be useful in 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
D000328:Adult; D002117:Calcitriol / Q000494:pharmacology*; D002118:Calcium / Q000494:pharmacology*; D015314:Dialysis Solutions; D005260:Female; D006801:Humans; D007975:Leukotriene B4 / Q000378:metabolism; D008264:Macrophages / Q000276:immunology*; D008297:Male; D010529:Peritoneal Cavity / Q000166:cytology; D010531:Peritoneal Dialysis, Continuous Ambulatory; D010538:Peritonitis / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology*; D013212:Staphylococcus epidermidis / Q000276:immunology*; D013481:Superoxides / Q000378:metabolism
D015314:Dialysis Solutions; D013481:Superoxides; D007975:Leukotriene B4; D002117:Calcitriol; D002118:Calcium