NxStage Medical Inc. amended its supply agreement with B. Braun Medical Inc. to provide Braun with its Streamline blood tubing sets.

The agreement calls for NxStage to supply newly-designed tubing sets for Bethlehem, Pa.-based B. Braun Medical’s Dialog and Dialog Plus hemodialysis systems in the U.S. Braun will handle sales, marketing and clinical support.

It’s an amendment of a contract originally signed by the two companies in October 2004, running through October 2011, with an option to renew, according to company officials.

Terms of the deal were not announced, but Kristen Sheppard, vice president of investor relations, told MassDevice that revenues derived from the contact have already been factored into NxStage’s guidance.

The company expects second-quarter revenues to be in the $33 million to $35 million range and $135 million to $145 million for the full year.