Can one have lupus if an ANA test is negative?
90-99% of lupus patients are ANA positive, but occasionally the ANA blood test will be negative even when lupus is present. Some possible explanations include ANA negative but anti-Ro or anti-SSA positive disease, complement deficiency state such as inheritied absence of C1q, C4 or C2, or measuring ANA during period of high dose steroid treatment that put the disease in remission.
