New Diagnostic Criteria

Change is in the wind.  Until now, the ACR’s diagnostic criteria for RA has been any four of the following:

  1. Morning stiffness, lasting for at least an hour, present daily for at least 6 weeks
  2. Arthritis of 3 or more joints, lasting for at least 6 weeks
  3. Arthritis of the hand joints, lasting for at least 6 weeks
  4. Symmetric arthritis, lasting for at least 6 weeks
  5. Rheumatoid nodules
  6. Positive rheumatoid factor (blood test)
  7. Joint changes on x-ray

Recently, the American College of Rheumatology collaborated with the European League Against Rheumatism to re-define diagnostic criteria.  Instead of needing to see evidence of long-term damage, the goal will be to treat RA aggressively enough that damage doesn’t occur. 

Now, instead of the aforementioned criteria, there is a scoresheet that looks at joint involvement, serology, duration of synovitis, and acute phase reactants:

Joint Involvement

  • 1 med-large joint (0 points)
  • 2-10 med-lg joints (1 point)
  • 1-3 small joints (2 points)
  • 4-10 small joints (3 points)
  • >10 joints (at least one small joint) (5 points)

Serology

  • Neither RF or ACPA positive (0 points)
  • At least one test low positive titer (2 points)
  • At least one test high positive titer (3 points)

Duration of Synovitis

  • <6 weeks (0 points)
  • >6 weeks (1 point)

Acute Phase Reactants

  • Neither ESR nor CRP abnormal (0 points)
  • Abnormal CRP or abnormal ESR (1 point)

Total score of six or more points means a definite RA diagnosis, even without x-ray evidence.  Doctors aren’t limited by normal sed rate, CRP, or RF.  A zillion joints involved for six or more weeks equates to a positive diagnosis without it mattering one bit what any lab results might say.

Patients can read more about it here.

__________
ACPA = anti-cyclic citrullinated peptide antibody (ie, anti-CCP test)

Bloodwork

How can it be that an analysis of that thick, red, sticky substance flowing through our veins can provide so much information?  It’s fascinating that so much can be learned about what’s going on in people’s bodies by taking a close look at their blood.  My doctors must feel the same way.  Sometimes I feel that they have me confused with a pincushion!

Every time my blood is drawn, the lab people send me a copy of the report they send to my doctor.  I highly recommend that everyone do this.  Get copies of all your labwork and store the reports where you can easily access them at a moment’s notice.  Knowing which tests have been previously run can save you money if you see a new doctor who doesn’t know that somebody else has already requested a specific test.  Sometimes it’s necessary to repeat a test, but not always.

I keep a spreadsheet tracking the fluctuations in those tests that are repeated frequently.  A spreadsheet isn’t required – it’s just another example of my controlling every detail I can.  Maybe I can’t control the actual lab values, but I can control what I know about them!

Initial Tests

ANA – Antinuclear Antibody  $82.58
Results are reported as a ratio and a pattern.  The ratio can be 1:40, 1:80, 1:160, 1:320, etc.  Patterns are speckled, nucleolar, peripheral/outline, or homogenous/diffuse.  Different patterns are associated with different autoimmune diseases.  My layman’s understanding of this test is that it doesn’t say exactly what the problem is, just that there’s some sort of autoimmune problem and hints at which direction to look.  Values can fluctuate.  My ANA results are what got me referred to a rheumatologist.  The rheumatologist then ranted about the uselessness of ever ordering an ANA since it didn’t give him any useful information.  My current rheumy must disagree since she ordered a repeat of the test (and the results were quite different, so it was worth repeating the test).

RF – Rheumatoid Factor  $25.92
This test has a higher than normal rate of false positives, and also a high rate of false negatives – so high that this test is not considered diagnostic.  RF is negative for 20% of RA patients (these people are said to be seronegative).  Which makes me wonder why the test is used at all now that the CCP is available.  The normal RF range at my lab is 0-15.

CCP – Cyclic Citrullinated Peptide Antibody $75.65
Also called anti-CCP, also called ACPA (anti-cyclic citrullinated peptide antibody).  This test is both more sensitive and specific than the RF test.  It’s a much more accurate test.  But then, I’m not a doctor. Maybe there’s a good reason to order the inaccurate RF instead of/in addition to the CCP.  The normal value for this test at my lab is <20.

Autoantibodies
Antibodies against measles, chicken pox, etc., are good things.  Antibodies to your own self are not good.  There are many different tests for different types of auto-antibodies that the doctor can order if symptoms indicate the need.

Inflammatory Markers

ESR – Erythrocyte Sedimentation Rate  $43.70
Also called sed rate.  Is considered a measurement of inflammation.  My lab’s normal range is 0-20.

CRP – C-Reactive Protein  $40.00
Tends to change quicker than ESR.  My lab’s normal range is 0.0-1.0

Routine Tests

This is where things get interesting.  Your doctor can check one or two little boxes on the order form and you receive a three-page report.  That’s because some tests are so commonly ordered as a group that the group has its own name.

I’m providing my lab’s normal value in parenthesis; different labs use different normal ranges.  The main thing to note is that these tests can fall outside of the normal range and still be okay.  If your doctor isn’t worried, then you shouldn’t be either.  There are links to the individual tests at Lab Tests Online, so I’ll just give the link to information about the group and let you track down the individual tests if you’re interested.  Medications can affect some of these, so it’s nice for your doctor to keep an eye on things and catch them early.

CBC - Complete Blood Count  $39.10
I loved deciphering the alphabet soup for these tests (my lab’s normal range in parenthesis):

  • WBC – White Blood Count (4.0-11.0)
  • RBC – Red Blood Count (3.8-5.2)
  • Hemoglobin (11.6-15.5)
  • Hematocrit (35-46)
  • MCV – Mean Corpuscular Volume (80-96)
  • MCH – Mean Corpuscular Hemoglobin (27-34)
  • MCHC – Mean Corpuscular Hemoglobin Concentrate (32-35.5)
  • RCDW – Red Cell Distribution Width (11.0-14.5)
  • Platelets (150-400)

Diff (Differential)
Sometimes my doctor orders a plain CBC (the above panel); sometimes CBC with diff is ordered.  The differential provides a breakdown of the different types of white cells:

  • Neutrophils (45-77)
  • Lymphocytes (12-44)
  • Monocytes (4.0-13.0)
  • Eosinophils (0.0-5.0)
  • Basophils (0.0-1.5)

BMP - Basic Metabolic Panel

Kidneys:

  • BUN – Blood Urea Nitrogen (8-24)
  • Creatinine (0.6-1.2)
  • GFR – Glomerular Filtration Rate (>59)

Electrolytes:

  • Sodium (135-145)
  • Potassium (3.6-5.3)
  • Chloride (98-109)
  • CO 2 (21-28)

Other:

  • Calcium (8.5-10.5)
  • Glucose (65-120)

CMP – Comprehensive Metabolic Panel  $42.26
This group of tests includes all of the BMP, plus a liver panel (which is why my doctors always order the CMP instead of the BMP).  For some reason, the liver function tests seem especially prone to going by two different names.  My PCP’s lab uses one name, and my rheumy’s lab uses the other name (so I get to learn both names).

  • AST/SGOT – Aspartate aminotransferase/Serum glutamic-oxaloacetic (5-40)
  • ALP/alk phos – Alkaline phosphatase (38-126)
  • SGPT/ALT – Serum glutamic-pyruvic transaminase/Alanine aminotransferase (5-50)
  • Bilirubin (total 0.2-1.4) or (direct 0.0-0.5)
  • Protein (6.3-8.0)
  • Albumin (3.2-5.0)

My labs also report:

  • Globulin (2.0-4.5)
  • A:G – Albumin to Globulin ratio (>1.0)

So… CBC, CMP, ESR, CRP comes to $165 every time!

Another time I’ll list costs on some of the extra tests my rheumy ordered.