EXHIBIT 23.1

            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

      We consent to the incorporation by reference in this Registration
Statement (Form S-8), pertaining to the La Jolla Pharmaceutical Company 2004
Equity Incentive Plan and the La Jolla Pharmaceutical Company 1995 Employee
Stock Purchase Plan, of our reports dated February 28, 2005, with respect to:
(1) the consolidated financial statements of La Jolla Pharmaceutical Company,
and (2) management's assessment of the effectiveness of internal control over
financial reporting, and the effectiveness of internal control over financial
reporting of La Jolla Pharmaceutical Company, included in the Annual Report
(Form 10-K), for the year ended December 31, 2004, filed with the Securities and
Exchange Commission.

                                      /s/ Ernst & Young LLP

San Diego, California
May 31, 2005