NEW YORK--(BUSINESS WIRE)--Fitch Ratings affirms SLM Student Loan Trust 2004-10 senior notes at 'AAAsf' and subordinate note at 'BBBsf'. The Rating Outlook remains Stable for both classes. KEY RATING DRIVERS High Collateral Quality: The trust collateral consists of 100% of Federal Family Education Loan Program (FFELP) loans. The credit quality of the trust collateral is high, in Fitch's opinion, based on the guarantees provided by the transaction's eligible guarantors and reinsurance provided b