ANCA in dialysis patients: a role for bioincompatibility?
BACKGROUND. Anti-neutrophil cytoplasmic autoantibodies (ANCA) have been described in patients suffering from systemic vasculitis such as Wegener granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome and other pathological conditions. In this paper we report a greater incidence of ANCA in hemodialysis patients as compared to peritoneal dialysis patients, pre-dialytic uremic patients and non-renal patients; a possible role for dialysis bioincompatibility in ANCA generation was also investigated.


METHODS
A total of 335 uremics in substitutive treatment (176 in hemodialytic treatment and 159 in peritoneal dialysis) were examined for ANCA positivity. A total of 189 patients with advanced renal failure in conservative treatment and 100 healthy subjects were used as control. The dialysis techniques were standard hemodialysis (n = 119), low volume hemodiafiltration (n = 26) and hemofiltration (n = 31). ANCA positivity was examined by immunofluorescence (IF): diffuse finely granular staining was considered as classical positive reaction (C-ANCA) and P-ANCA was diagnosed if a perinuclear staining was observed. EIA for proteinase-3 (anti PR-3) and myeloperoxidase-antibodies (anti-MPO) were also performed.


RESULTS
In non-renal patients and in patients with pre-dialytic renal insufficiency none were found ANCA positive. In peritoneal dialysis patients all but one were ANCA negative with IF, with all EIA test resulting negative. In hemodialytic patients, a positive IF test was found in 26 (14.7%) for P-ANCA and in 5 (2.8%) for C-ANCA; using the EIA test 23 (13%) patients were positive for MPO and 12 (6.8%) for PR-3.


CONCLUSIONS
No correlation with age, primary renal diseases, dialytic age, dialysis membrane materials was found; regarding the different extracorporeal dialytic techniques a higher incidence (p < 0.02) was detected in patients undergoing HDF Backfiltration of contaminated dialysate may induce ANCA via an increased cytokine generation.
Andreini
B
B
Internal Medicine Department, University of Pisa, Italy.
Panichi
V
V
Cirami
C
C
Migliori
M
M
De Pietro
S
S
Taccola
D
D
Aloisi
M
M
Antonelli
A
A
Giusti
R
R
Rindi
P
P
Buoncristiani
U
U
Giovannini
L
L
Palla
R
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D007676:Kidney Failure, Chronic / Q000276:immunology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D012372:ROC Curve; D006435:Renal Dialysis; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014511:Uremia / Q000276:immunology / Q000628:therapy
D019268:Antibodies, Antineutrophil Cytoplasmic