Common Variable Accuracy Deficiency

Lord Imp has recently gotten into watching House, and a couple of days ago he was chatting with me excitedly about watching an episode where a character was diagnosed with CVID. He was all giddy, telling me that he had it figured out 10 minutes in cause that’s what it sounded like. Bless his little heart, he tries so hard to understand the biology behind everything I go through. So I decided to watch it for myself to see what was up and to look at it from a different perspective now that I actually have the rare condition that was talked about.

From the get-go, I found myself wanting to beat my head on the keyboard. Who the hell calls toxoplasmosis a fungus? Idiot show writers who got their information off of Wikipedia, that’s who. Toxoplasmosis is caused by the protozoan Toxoplasma gondii. It’s a parasite. And P.S. I got that from Wikipedia, my microbiology textbook has been packed, didn’t think I was gonna need it until I moved…HA!

The slight fact that they’ve put toxoplasmosis in the wrong kingdom aside, let’s take a minute to talk about presentation. CVID will typically present as recurrent sinus, pulmonary and/or ear infections. Even House said that he wasn’t having the usual pulmonary infections. We’ll leave that point for a minute and allow the writers the benefit of the assumption that someone with CVID has issues fighting any sort of infection, no matter what kind. Where is the recurrence? Where is the pattern of frequent infections? He comes down with one fungal pneumonia and OMG, he’s got CVID! No, sorry folks, that’s not quite how it works.

He also has an extremely low T-cell count. Low T-cells and low B-cells. Sounds more like SCID to me. Which he wouldn’t have made it to kindergarten if had it. There are many reasons to have a low T-cell count, and it can spontaneously develop. According to Medscape, a T-cell deficit can cause a lack of communication between T- and B-cells, causing those B-cells to not reach maturity and leading to the Ig deficiency that is the hallmark of CVID. So that is entirely possible, although I call bullshit on their analysis that this miscommunication is the sole cause and reason behind CVID, seeing as I am a person with perfectly normal (and rather robust, as a matter of fact) T-cells at healthy levels.

And then there’s the testing. I’m going to leave the fact that they told the patient that he had AIDS before even drawing blood and doing a test, and focus instead on the testing itself. For starters, from what I’ve read on several sources, the AIDS test is going to be automatically a double-test when the ELISA comes back positive and it is followed up by a Western blot. House ordered a second test after the first positive, and that one came back negative. If what I am reading is correct, that Western blot should have caught the error, making another blood draw unnecessary. And why not run an Ig assay anyway since toxoplasmosis only progresses in immunocompromised patients? It’s a very inexpensive test, and since you were looking at someone with immune issues, ALL parts of the immune system should have been checked, not just one class. The hairy cell leukemia could have been ruled out with a simple complete blood count and flow cytometry of, funny story, cells in the immune system. AKA killing two birds with one stone. Half a dozen vials of blood in one draw (yeah, a bit of an exaggeration, but you get the point) and a lot of the bullshit could have been avoided.

Now, back to the AIDS bit. Who in the HELL tells a patient they have AIDS before even doing a blood test?? I mean, that just BLEW my mind. That’s like, medical epic fail #1, telling a patient they have a socially stigmatizing and awful illness WITHOUT RUNNING A TEST. OMG I just can’t even wrap my tiny brain around it. That’s just….AAAAAAHHH!!!

Putting the ethics aside and back to the hair-pulling…

The Epstein-Barr virus as well as the epilepsy medication the patient was on as a child are both associated with CVID – on their own. I was unable to find anything saying that the combination was what was associated with it. And the phenytoin he was on seems to only cause temporary CVID, Pub Med had an article where they looked at a guy who developed CVID-like symptoms while on phenytoin – which reversed after coming off the drug. Many drugs can cause low Ig levels, this is not  uncommon at all. However everything I read said that phenytoin-induced Ig deficiency is extremely rare. And it looks to me like it’s impossible to have 30 years later since it appears to only be a temporary side effect of the epilepsy medication.

So then they put the patient on IVIG and BAM! All of a sudden he’s magically cured immediately. Oh, I wish it were that easy. It can take anywhere up to 6 months of continual infusions to get yourself to a point when you are feeling amazing – although after a lifetime of illness, a couple days after your first infusion you do see a noticeable difference. I’m also really confused how IVIG got his T-cells back to normal, too…yeah, if you’re deficient in it, that IVIG isn’t going to do you a damn bit of good, all it’s going to boost up is your IgG levels. Your T-cells are produced by your bone marrow and refined in the thymus, and if you don’t have any you either have some serious production issues going on, you’re on some kind of immunosuppressant, or you have one of a small handful of other illnesses. Either way, one round of IVIG is not going to get your T-cells up. Sorry, Charlie.

And the final, big question…Cameron is a FUCKING IMMUNOLOGIST. WHYYYYYY did she not open her mouth? Sure, Chase mentioned immunoglobulin deficiency and House shot him down, but COME ON. There are a rather large number of immunodeficiencies out there, you have a patient presenting an illness that a healthy person shouldn’t, hello this is your field! Does House own the hospital? No. You’re a doctor, you can order tests just as well as any other guy. I mean sure,  you would have to deal with House’s attitude problem, but he has a short memory, he’ll forget about it in the next episode.

So yes. This is my somewhat-educated, I-am-no-expert rendition of what I found wrong in the episode that I really can think of. I would just like to take this moment to say that all I had to do was use Google. How hard is it for a show’s writers to do? They had to have had a medical expert on the writing staff, you can’t begin to convince me that a medical expert would repeatedly refer to toxoplasmosis as a fungus. Unless there’s just some other organism that causes it. I’m too tired to do that much research. But I digress, everything I found was publicly and freely available, and not that hard to find. Come on, make it a little more accurate, folks.

But then again, it wouldn’t have been that dramatic had they done it the way it should have been done, and had they made it present the way that it should have. Would have made for an awfully boring episode…


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