Blood test: Alternate explanations for high iron serum?

Factual Questions
1

First of all, let me say that I am seeing a medical professional about this. In fact, I wouldn’t even know about it otherwise. I know that the opinions of random people on the Internet are no substitute for a doctor, and I don’t intend to act otherwise.

On some blood tests I had recently, I had unusually high levels of serum iron and iron saturation (74% saturation on Feb. 13, and 79% on April 11-- More details available, if they’re relevant). My primary care provider suspects heriditary hemochromatosis, and has ordered a gene test to definitively confirm or deny it. I will, of course, take the test, on her recommendation (it can’t hurt, and my health plan will completely cover it), but I suspect that that’s not it.

First of all, from what I’m reading, carriers of the gene typically have blood iron levels a bit higher than normal (though not enough to cause problems), but both of my parents are on the low end. Second, I have a large enough extended family that I would expect that there would already be some family history of the disease, which (so far as I know) there is not. Also, I don’t have any of the other symptoms, though that may not be significant (most symptoms don’t typically show up until after my age).

So, again, I will take the gene test, but in the event that it comes up negative, what are some other possible explanations for my high iron? Could it be dietary? Am I just an outlier on the normal variation? Is there some other rare disease which causes high iron saturation? Am I slowly turning into a superhero with a body of living steel?

2

Have you had your liver enzymes checked? I can’t speak to your iron levels, but I think that some liver problem can cause pseudo-hemochromatosis.

Edited to add:

3

Yes, in fact, those were part of the same battery of tests which found the high iron. All of them (total and direct bilirubin, alkaline phosphatase, GGTP, serum LD, AST (SGOT), and ALT (SGPT) ) were within the normal ranges, on both tests. It’s my understanding, though, that the causation there actually goes the other way: High iron levels can impact liver function, not the reverse.

4

My understanding is that it goes both ways–iron impacts liver, liver trouble can increase iron. Sorry not to be more helpful.

5

I’m sure you’ve read that hemochromatosis can be associated with hypothyroidism, but T3 and T4 levels are commonly checked in blood tests so I’m assuming those were done and found within range. I’d be curious about testosterone and estradiol levels as well as they play off each other and can cause a rise in hematocrit and so you’d have to speculate that hormones as well as enzymes could be at work here. I know that hematocrit is not related to hemochromatosis, I’m just spitballing the idea that hormones could be playing a role.

There are just so many possible factors and beling a little high here and a little low there, all within range, and who knows what you’re going to get. The problem with blood test reference ranges is that they don’t tell you what is normal for you.

I’d certainly want to read as much as I could find and keep an eye out for symptoms and then make sure I had mathcing red thigh-high boots and gauntlet gloves handy for when those super powers kick in.

Those raw liver milk shakes six times a day could be doing it…

6

In veterinary medicine, hemochromatosis is very rare, other than in the Mynah Bird and Toucans.

http://www.mynahbird.com/articles/ironstorage/ironstorage.html

7

Can’t help with the diagnosis, but “Chronos Colossus” is an excellent name for a disease. :slight_smile: Let us know when you switch-over so we can throw mangetic darts at you.

8

I don’t see T3 or T4 (nor thyroxine nor triiodothyronine) listed on these test results, unless they’re also known by some other name. And there’s nothing I recognize as a hormone listed, certainly not testosterone.

9

Do you take iron supplements? Eat red meat every day?
What were your haemoglobin and haematocrit (not the same thing)?

Anyhow, there’s always a chance of a de novo mutation.

10

[QUOTE=Chronos]
On some blood tests I had recently, I had unusually high levels of serum iron and iron saturation (74% saturation on Feb. 13, and 79% on April 11-- More details available, if they’re relevant). My primary care provider suspects heriditary hemochromatosis, and has ordered a gene test to definitively confirm or deny it. So, again, I will take the gene test, but in the event that it comes up negative
[/QUOTE]
Indeed, iron saturation levels in the mid 70 percent range are high, although not what you sometimes see in homozygous hemochromatosis, where you can get results like 99 or even 100%.

BTW, before I go any further, the gene that’s tested for in hemochromatosis is very common (and, IIRC, has been termed the most prevalent single gene disorder in Man). Its frequency is about 1 in 8. So, the likelihood that both of two randomly chosen people carry it is 1/8 X 1/8 = 1/64. In their offspring, the likelihood of any one child getting the “bad” gene from both mom and dad is, of course, 1/4. Hence, you get 1/64 X 1/4 = 1/256 chance of any randomly chosen individual having the disease. (Note that there are other genes involved as well, but these have not yet been characterized. So, if a person has a negative test for the “bad gene” it does not completely rule out the disease.)

Now getting back to saturation, this table may be of interest (it’s from the Annals of Internal Medicine 2002). Bottom line is, that for men, a saturation of over 50% is about 98% specific for hemochroamtosis. In other words, if a man has an iron saturation of over 50% there is only a 2 percent chance that he doesn’t have the disease. Generally, “specificity” is, of all the people with a positive test result, the percentage who actually have the disease. 98% specificity is excellent. It means that there’s only a 2% false-positive rate.

(btw, “sensitivity” is, that of all those people with the disease, what percentage will have a positive test result. So, a sensitivity of 75% means that of all the people with hemochromatosis, only 75% will be picked up by the test. In this instance, then there is a 25% rate of false-negative tests.)

11

A few other things:

In this unreadable, lengthy article, figure 2 will be of some interest. It gives an algorithm of how to proceed to check for hemochromatosis in someone with a negative family and a high iron saturation.

Now, I neglected to answer what I think is your primary question - other than hemochromatosis, what else can raise a person’s iron saturation so high?

Well, a list of causes might include:

  • chronic liver disease (e.g. hepB or hep C)
  • repeated transfusions (i.e. scores of transfusions or more)
  • porphyria cutanea tarda (a disease affecting both the liver and the skin. In the latter, one gets skin blistering on sun exposed areas. Here’s a picture. In PCT, excessive hair growth can also be prominent - some people think the “Werewolf” myth had it’s origins in someone who had porphyria cutanea tarda))

There you go.

12

On NPR a couple weeks ago I caught a bit of an interview with somebody who had very high blood iron. I think maybe he was himself a doctor, or in any case was active somehow in treatment or research of his condition. I don’t remember what he called the condition. But central to the whole thing was that men more often have a problem with two much iron, while women more often have too little. He said giving very frequent blood donations were a sufficient treatment in his case.

13

Right-- If this is hemochromatosis, we’ll know soon enough, but if it turns out it isn’t, I want to know what else to look for. I hadn’t realized that the specificity of high iron by itself was so high, though… That’s very interesting. And I don’t have any reason to suspect hepatitis or other liver disease, and I definitely haven’t had repeated transfusions or porphyria.

The primary treatment for hemochromatosis is phlebotomy, which is basically the same procedure as blood donation. But for treatment of the disease, it can be as often as multiple times per week, while the Red Cross won’t take donations more frequent than once every 8 weeks. Ironically (pun retroactively intended), I usually do donate blood, but since this came up, I’ve been holding off until we find out what it is (both to not throw off any test results, and in case it turns out to be something which contraindicates blood donation).

14

[QUOTE=Chronos]
The primary treatment for hemochromatosis is phlebotomy, which is basically the same procedure as blood donation. But for treatment of the disease, it can be as often as multiple times per week, while the Red Cross won’t take donations more frequent than once every 8 weeks.
[/QUOTE]
Well, most people with the disease wind up getting phlebotomy less than that, maybe once a week or even less. OTOH, the Red Cross assumes that a person is starting with a normal amount of iron and that frequent donations would make them iron deficient. That’s less of a problem, of course, with hemochromatosis.

15

Hmm, you say phlebotomy, I say venesection! Phlebotomy to me means taking the usual small blood samples for routine tests.

The hospital I work in has 3 days a week when we do 2 sessions of venesection for haemochromatosis patients, usually 6 patients at each session. That’s 36 people every week, and most come every month. We take 500mls at each session, it’s just like a blood donation, but the blood gets chucked out (our blood tranfusion service declines haemochromatosis blood).

Mostly they turn up, roll up their sleeve and point to the vein they want me to use, I stick the needle in, go away, come back when the bag is full, take the needle out and they go home. They get tea and a biscuit and a newspaper while they wait, it is quite civilised.

16

[QUOTE=irishgirl]
(our blood tranfusion service declines haemochromatosis blood).

[/QUOTE]

Any idea why? It seems like a hemoncentrated sample would be ideal. Practically packed rbcs!

17

Not much to add here except that I used to perform the genetic test you’re getting, and there’s a small but significant chance that it will be performed in our lab. I also know far more than anyone here wants to know about the molecular biology of hereditary hemochromatosis. I do think it’s kind of amusing that it can be treated with theraputic phlebotomy, or as they used to call it in the old days, bloodletting.

18

Oh, I’ve been getting a laugh out of that, too. And I intend to ask, next opportunity I can get, whether the blood taken can be donated. It seems like such a waste to just throw it out, for a non-communicable disease.

19

[QUOTE=vetbridge]
Any idea why? It seems like a hemoncentrated sample would be ideal. Practically packed rbcs!
[/QUOTE]
There used to be a concern that the disease might be transmissible. Now that it is known to be a strictly heritable, the major impediment toward using the blood is bureaucratic; the blood must be taken regardless, but if it can’t be used for donation due to other reasons (illness, risk factors) it has to be seperated out and destroyed. In the past, all haemochromated blood was automatically disposed of or had to be handled specially; to put it into the general supply of blood the center/bank has to obtain a variance from the FDA and follow additional guidelines and procedures. Otherwise, other than the high iron concentration, blood from haemochromatosis is no different from any other blood.

Stranger

20

Our transfusion service dclines the blood for the reason that we take 6 lots of blood at every venesection clinic, and only 1 or 2 of those 6 patients would be suitable blood donors (our HH patients tend to be on medications for complications, or to have other risk factors which make them unsuitable donors).

By the time that the suitable blood had been separated from the others, double checked as safe for transfusionand transported to the blood bank, it would almost certainly be unusable.