Monday, August 28, 2006

Alpha-1 AT

So, I saw a patient last week for Alpha-1 AT deficiency. Phenotypically, she has the disease--lower lobe emphysema, severe obstructive disease (FEV1 of 1.0 L which improved to 1.35 while on augmentation therapy with Prolastin). She has a family history of the disease and is a non-smoker (with substantial second-hand exposure). Her measured enzyme level, prior to the start of weekly Prolastin, was 31 mg/dl (lab range for normal is 100-190 mg/dl).

So, the interesting thing is that she (and her family members with the disease) has an M-Z genotype, which should be a "normal" phenotype without disease. The genotype was confirmed with separate studies, as was her son's genotype.

Anyone seen this before? Any comments?

4 comments - CLICK HERE to read & add your own!:

Baleeiro said...

I have one patient with M-Z phenotype with a level~70 who has severe COPD but she is a heavy smoker (still) and when she came to me her FEV1 was already ~30% with no reversibility...

SSandhaus said...

As a pulmonologist who follows over 2,500 patients with Alpha-1, I have NEVER seen a true PiMZ with a level of 31 mg/dl. First are you certain the level result wasn't reported in micromoles (where a level of 31 would be normal). Second, although I know you've already confirmed the genotype, if this was done in a commercial lab, they rarely if ever test for unusual genotypes (they don't have the probes to do this). If you only sent samples for genotyping, rather than phenotyping, this can be the problem, since genotyping usually only uses probes for the Z and S genes, and none of the 30 or so rarer deficient genotypes. If you haven't done this already, I would suggest contacting the Alpha-1 Testing lab at University of Florida, run by Dr. Mark Brantly. He can do more extensive testing.

Jeff H said...

Thanks for the comment. As noted, the level of 31 is mg/dl (and not micromoles) - that was the first thing I checked, as prior to two weeks ago she was seeing another pulmonologist. I mistakenly reported an MZ-genotype, it is, in fact, reported as an M-Z phenotype by Mayo Medical laboratories.

Brian said...

I am a 56 year old COPD patient.
When Dx seven years ago I was tested for Alpha 1 and told it was not a factor in my case.
This has long raised a question in my mind as I was informed that Alpha 1 is the only congenital variant of COPD,yet virtually all the males of two generations before me have died of it,I have it and my son was recently told by his doctor he has "pre emphysema"(?)
Should we be tested using the lesser known markers a previous writer has mentioned?