When we read the symptomology of SLE it generally reads like her everyday life, but they're saying scores <100au/ml indicate negative despite the reference being none preset?
This is the kind of thing that happens when a GP or PCP who is not trained or experienced with auto-immune diseases tries to diagnose rather than referring you to a rheumatologist... you really need a rheumatologist who is the expert in these types of diseases.
Typically, four or more of the following eleven criteria must be present to make a diagnosis of Systemic Lupus. Only a couple of these have anything to do with blood work, and it sounds like your current Dr is relying solely on blood work!! Your wife may very well have Lupus or another auto-immune disorder - it can and does appear sometimes without anything showing up in laboratory tests.
1. Malar rash: butterfly-shaped rash across cheeks and nose
2. Discoid (skin) rash: raised red patches
3. Photosensitivity: skin rash as result of unusual reaction to sunlight
4. Mouth or nose ulcers: usually painless
5. Arthritis (non-erosive) in two or more joints, along with tenderness, swelling, or effusion. With non-erosive arthritis, the bones around joints don’t get destroyed.
6. Cardio-pulmonary involvement: inflammation of the lining around the heart (pericarditis) and/or lungs (pleuritis)
7. Neurological disorder: seizures and/or psychosis
8. Renal (kidney) disorder: excessive protein in the urine, or cellular casts in the urine
9. Hematologic (blood) disorder: hemolytic anemia, low white blood cell count, or low platelet count
10. Immunologic disorder: antibodies to double stranded DNA, antibodies to Sm, or antibodies to cardiolipin
11. Antinuclear antibodies (ANA): a positive test in the absence of drugs known to induce it.
I suggest you have a workup done by a Lupus-aware rheumatologist! I suggest checking with the Lupus Org at www.lupus.org
to find your local chapter of the organization. Then check in with the local chapter to see which local Drs are active on the advisory board -- these are generally the Drs most interested in and most experienced with Lupus in your area.
Let us know how it goes,
Lynnwood, Lupus & Sjogren's Moderator, Dx: 2000DIAGNOSING LUPUS & HW's LUPUS 101
"Life is far too important to be taken seriously." - Oscar Wilde