Each 'disorder' would have it's own ELISA - they don't all get tested for with just one test.
Also remember that the ELISA and WB are both antibody tests - and since you have had steroids, the immune system will respond even less, since Lyme alone can reduce the immune response. The likelihood of you getting a positive WB at this point is pretty slim when you consider these two factors.
I would encourage you to go for the PCR tests - they look for the DNA of the bacteria in your blood, & urine. The spinal fluid and synovial fluid (like from a knee) can also be tested in this manner.
While not all diseases/infections have been studied to see if they too produce a low CD57, this is what has been found by some very good Lyme researchers:
"In a cross-sectional study, patients with
acute Lyme disease (defined as disease occurring within
one month of infection) were found to have normal levels
of CD57 cells, while untreated patients with chronic
Lyme disease (defined as disease occurring more than 3
months after infection) were found to have decreased
CD57 lymphocyte levels. We have now documented a
decrease in this lymphocyte subset over 10 years in
conjunction with relapsing and remitting symptoms of the
disease. This finding reinforces the concept that chronic
Lyme disease is associated with a persistent immunologic
defect that prevents the infection from being cleared by
the immune system. Our observation also provides further
evidence that a decrease in the CD57 subset may be a
valuable marker of chronic infection with the Lyme
disease spirochete.
www.anapsid.org/cnd/files/strickercd57.pdf Also, you should know that you have alternatives to long term antibiotics for the tick-borne infections. Many here use herbs to help with treatment or as a stand alone treatment and are healing.