Serum antibodies against Saccharomyces cerevisiae: a new prognostic indicator in metastatic renal-cell carcinoma.
OBJECTIVE
A recent study reported that a diet rich in bread and refined cereals might have an unfavorable role in the development of renal cell carcinoma (RCC). To test whether an underlying intolerance of bread ingredients is responsible for the unfavorable influence of bread on RCC, we examined patient sera for the presence of food-specific IgG.


METHODS
A commercial test was used to detect food-specific IgG directed against a panel of 113 food antigens in sera of 54 patients with metastatic RCC. Kaplan-Meier estimates were used for univariate survival analysis, and differences in survival curves were assessed with the log-rank test. Multivariate survival analysis was done using a Cox regression model.


RESULTS
We found that RCC patients with elevated serum levels of IgG antibodies against S. cerevisiae, commonly known as baker's yeast and yet another bread component, have an unfavorable clinical course. Median survival of patients with high levels of S. cerevisiae IgG was only 17.8 months, whereas median survival of patients with low S. cerevisiae IgG was 43.8 months (P = 0.0022; log-rank). Multivariate survival analysis identified high levels of S. cerevisiae IgG as a strong and independent prognostic risk factor (risk ratio 4.6, P = 0.001; 95% CI 1.61-13.08).


CONCLUSIONS
Our findings indicate that serum levels of IgG against S. cerevisiae may predict survival in patients with metastatic RCC. The data suggest not cereals but baker's yeast being the critical component of bread that may cause immune deviation and impaired immunosurveillance in predisposed RCC patients.
Ramoner
Reinhold
R
Immunotherapy Unit, Department of Urology, Innsbruck Medical University, Innrain 66a, 6020, Innsbruck, Austria.
Rahm
Andrea
A
Gander
Hubert
H
Stollenwerk
Björn
B
Falkensammer
Claudia
C
Leonhartsberger
Nicolai
N
Thurnher
Martin
M
D000328:Adult; D002292:Carcinoma, Renal Cell / Q000097:blood* / Q000556:secondary / Q000628:therapy; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007167:Immunotherapy; D007680:Kidney Neoplasms / Q000097:blood* / Q000556:secondary / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012441:Saccharomyces cerevisiae / Q000276:immunology*; D016019:Survival Analysis; D016896:Treatment Outcome
D007074:Immunoglobulin G