Kudos for knowing what HDL's are. To me they're High-Density Lipoprotein. :)

The problem presented by the OP only showed single alpha-character identifiers, so I went with \w. If there's a larger set of permissible identifiers, he might use an explicit character class, and if the identifiers may be longer than a single character, he might specify a quantifier. Greediness shouldn't be an issue since I'm explicitly anchoring to the start of the line, and to ='.