Friday, February 16, 2007

Diagnosing Behcet's -- Part 2 (HLA testing)

I'm taking a look at the different types of information that doctors use in diagnosing a case of Behcet's disease. As a reminder, there are no specific blood test results, lab results or biopsy results that will definitely tell a doctor that you have Behcet's. Each of the posts that I make over the next few days will only provide a small piece of the puzzle. You need a doctor who's experienced in Behcet's diagnosis and treatment to pull all of the pieces together. The American Behcet's Disease Association maintains a Doctors' Registry on their website that lists patient-recommended doctors across the U.S. You can access the list here.

The following information is adapted from Essential Guide to Behcet's Disease, c.2003 J Zeis. References (appearing in parentheses) can be provided on request.

\\ HLA blood testing can help in diagnosis of Behcet's disease, although patients need to understand that the results are not specific to Behçet's (they also appear in people with other illnesses, and in people who are perfectly healthy), the test is expensive, it may not be covered by health insurance, and the final report can take weeks to arrive.

HLA stands for human leukocyte antigen. HLA types are inherited from both parents. The HLA types that appear on your test results will never change during your lifetime-just as your blood type (A, B, AB or O) always stays the same. HLA testing is used most often to see if organ donors and organ recipients are compatible, and it is also used for genetic counseling. Research over several decades has shown that HLA-B5 is found more often in the blood of Behçet's patients in Japan, Italy, Korea and Turkey, than in healthy people.(11) Zouboulis (1999) states that HLA-B51 presents a high risk for Behçet's disease in "a small geographic area of the Mediterranean Sea countries and Southern Asia."(146) HLA-B51, HLA-B52, HLA-B5101, and HLA-DR3 have also been implicated in Behçet's studies from various countries(11,14,40).

There is apparently no relationship between HLA results and Behçet's disease for patients in the US(12) and the UK(13). It should be noted, however, that a patient's ethnic background is more important in HLA typing than whether s/he is a resident of a Western country like the US.

While blood for an HLA test is drawn in the same way as standard blood tests, the HLA blood sample is usually forwarded to a specialized lab for processing. Your doctor may request that the lab produce results for HLA-A, HLA-B, HLA-C and/or HLA-D types. Your test results will arrive showing all of the HLA types that appear in your blood. Contrary to popular belief, your results won't show up stating that you "tested positive (or negative) for Behcet's", or "tested positive (or negative) for HLA-B5 or B51". For example, my doctor asked for HLA-A and HLA-B tests to be performed, and my report showed the following:

HLA AB Type: A2, A23; B7, B50

HLA-C and HLA-D testing was not performed (although I wish it had been, because new HLA links to various diseases are being found every year).

You can tell from my test results that I don't carry either of the typical HLA types that are common to Behçet's disease (B5 or B51). However, several research studies mention the possible involvement of HLA-A2 in situations where BD has shown up in more than one family member(189,191) - which may apply in my case. It's important to ask your doctor what the full results are from your HLA test, so that you can have a copy in your own records at home for future reference. Even if you don't carry any of the typical BD-type results, researchers have found links between some HLA results and other autoimmune and/or rheumatic diseases. For example, the following HLA types have been linked to cases of multiple sclerosis -- A3, DR15, DRB1, DRB5, DQB1; and lupus -- B8, DR3. If doctors are on the borderline between diagnosing you with Behcet's, MS, or lupus (or a combination of 2 of them, which is also possible), your total HLA "picture" will give them more information to work with.

"What does all of this HLA lingo mean to me, as a Behçet's patient?"
It means that there's much more to a Behçet's diagnosis than a simple test. If you have an HLA blood test that shows HLA-B5, B51, B5101, or DR3, there is a higher probability that Behçet's will be your diagnosis, than if those results hadn't shown up. However, Lee (2001), gives a general idea of the odds with the following statement: "In humans, Behçet's disease occurs in only 1 of 1000 individuals who have the HLA-B51 phenotype."(188)

It's important to know that you don't have to show ANY of the typical Behcet's-related HLA types in order to be diagnosed with Behçet's: physicians base a diagnosis on a combination of observed physical signs and symptoms, their personal experience in treating Behçet's patients, the patient's medical history, and the patient's test results.

Wednesday, February 14, 2007

Diagnosing Behcet's -- Part 1 (Lab tests)

Over the next few days, I'm going to take a look at the different types of information that doctors use in diagnosing a case of Behcet's disease. As a reminder, there are no specific blood test results, lab results or biopsy results that will tell a doctor that you have Behcet's. Each of the posts that I make this week will only provide a small piece of the puzzle. You need a doctor who's experienced in Behcet's diagnosis and treatment to pull all the pieces together. The American Behcet's Disease Association maintains a Doctors' Registry on their website that lists patient-recommended doctors across the U.S. You can access the list here.

The following information is from Essential Guide to Behcet's Disease (c 2003 J Zeis). References appear in parentheses and can be supplied separately.

\\ Even though there are no tests that will definitely diagnose
a case of Behçet's, certain test results can appear more
frequently in BD patients. However, NONE of the results
listed below are specifically required for diagnosis.
For example :

1) neutrophil and platelet counts may be increased(80)
2) C-reactive protein (CRP) and ESR may be elevated, and
may correlate w/disease activity(81) [O'Duffy (1997) states
that it is possible to have active disease (i.e.uveitis) when
serum and ESR levels are normal(117)]
3) ANCA, ANA, and antiphospholipid antibodies are usually
absent(80)
4) lesions may show a mixed leukocytic infiltration of
neutrophils and mononuclear cells into tissues(80), evidence
of cutaneous leukocytoclastic vasculitis(98) or frank
necrotizing vasculitis(117)
5) serum immunoglobulins, especially IgA, may be elevated
(82). IgA, IgG and IgM levels may show nonspecific elevations
in active neuro-Behçet's.(117)
6) circulating immune complexes (CIC) may be elevated,
and may be related to disease activity(85)
7) C3 levels in the cerebrospinal fluid tend to be elevated(83)
8) C9 serum levels may also be elevated(83)
9) clotting time, bleeding time, prothrombin time, and partial
thromboplastin time tend to be normal(84)
10) fibrinogen levels may be elevated, and may parallel
disease activity(84)
11) IL-8 serum levels may be increased in patients with
active oral and neurological symptoms(86)
12) serum amyloid A, and beta-2 microglobulin levels may
be elevated, and may closely parallel disease activity
(Aygunduz et al, 2000, found these tests to be even more
sensitive than ESR and CRP levels) (108)
13) rheumatoid factor (RF) may be present, regardless
of disease activity(88,89) \\


MEDICAL JOURNAL ARTICLES & RESEARCH
Immunoglobulin E: a new diagnostic clue
for Behcet's disease? IgE and Behcet's disease.

The FULL-TEXT PDF of this article is
available online.

Clin Rheumatol. 2007 Jan;26(1):81-3.
Onat AM, Buyukhatipoglu H, Yilmaz M, Geyik R,
Celik A, Ozturk MA.
Department of Rheumatology, School of Medicine,
Gaziantep University, Gaziantep, Turkey.
mesutonat@yahoo.com

Tuesday, February 13, 2007

American Behcet's Disease Association 2007 Conference

Get your information from doctors who actually understand
Behcet's (and know how to spell it, too!)
This will be the fifth time I've attended an ABDA conference,
and the first time that I'll be giving a presentation. The topic?
Behcet's and Pregnancy, which was the subject of the
research study that I conducted in late 2005-spring 2006.

If you've never attended an ABDA conference before, try
to to make it a priority for this year. It's been 4 years since
the last conference took place, and it may be another 2-4 years
before the next one is scheduled. You owe it to yourself to
collect as much information as possible for you, your family,
and your doctors.

ABDA 2007 Medical Conference
Friday April 27 - Sunday April 29, 2007
Clarion Hotels & Suites Emerald Springs
Las Vegas, NV

Conference Fee: $395
They accept checks, money orders, MasterCard/VISA. There's an
additional $40 off the registration fee if you're an ABDA member.

Hotel Cost: the ABDA has arranged a special $99-per-nite rate
with the hotel, and you have to let them know that you're with the
American Behcet's Disease Association conference to get the
special rate (or even to get a room at all -- if you're not with the
conference, they're telling people that there are no rooms available
that weekend). You can get a room by calling 1-800-732-7889 in
the US and Canada.

The first session of the conference starts at 9 AM on the 27th, so
anyone planning on attending should expect to arrive in Vegas
the day/night before. The last presentation ends at noon on
Sunday the 29th. I was able to get a round-trip airline ticket
from Boston to Vegas for $282 total, altho I have to arrive late
at night before the conference, and take the red-eye flight back
home to get that particular fare.

Sessions run from 9 AM until 5 PM each day, with evening
support groups for BD patients, and for the caregivers/family
members of BD patients. (Don't worry, there are scheduled
breaks during the day, and a 2-hour lunch/rest break each
day too).

If you want to pay by check or money order,
the address to send your payment is:
ABDA 2007 Conference
PO Box 19952
Amarillo, TX 79114

The conference moves around the country each time it's offered.
Locations for the last few conferences have been:
Las Vegas (this year)
Chicago (2003)
Boston
Nashville
Phoenix

MEDICAL JOURNAL ARTICLES & RESEARCH

What Does It Take to Diagnose Behcet Disease?
Date Published: February 5, 2007
Description: This patient had many typical features but no oral or genital ulcers. His ocular disease responded to treatment with azathioprine and infliximab.
Source: JCR: Journal of Clinical Rheumatology