Nephritic vs. nephrotic syndrome

One of the things we talked about this week in our Renal Path lecture was nephritic and nephrotic syndromes. I thought it might help to review them a bit, since they can be maddeningly frustrating if you don’t understand the underlying principle in each one.

So here are the four main characteristics of each:

Nephrotic syndrome

  1. Massive proteinuria
  2. Hypoalbuminemia
  3. Edema
  4. Hyperlipidemia/hyperlipiduria

Nephritic syndrome:

  1. Hematuria
  2. Oliguria
  3. Azotemia
  4. Hypertension

How do you make these lists hang together in a way that you can remember?

First, let’s take nephrotic syndrome. The thing to remember for this one is massive proteinuria. You might do this by remembering that nephrotic and protein both have an “o” in them. The massive proteinuria in these patients leads to hypoalbuminemia (they are peeing out albumin!), which results in edema (the oncotic pressure in the blood goes down, and fluid leaks out of the vasculature into the surrounding tissue). So right there, you have three of the four features, just by remembering one. The cause of the last feature, hyperlipidemia/hyperlipiduria, is less well-understood, so you’re just going to have to memorize that one. As an aside, nephrotic syndrome is often more dangerous than nephritic syndrome, so you might want to think of this syndrome as the “oh sh*t” syndrome (again – nephrotic has an o in it, nephritic does not). Crude, but if it works, who cares?

In nephritic syndrome, there is some proteinuria and edema, but it’s not nearly as severe as in nephrotic syndrome. The thing with nephritic syndrome is that the lesions causing it all have increased cellularity within the glomeruli, accompanied by a leukocytic infiltrate (hence the suffix “-itic”). The inflammation injures capillary walls, permitting escape of red cells into urine. Hemodynamic changes cause a decreased glomerular filtration rate (manifested clinically as oliguria and azotemia). The hypertension seen in nephritic syndrome is probably a result of fluid retention and increased renin released from ischemic kidneys.

If you really want to pare it down – if you only have enough brain space to remember one feature for each disorder – remember that nephrotic syndrome is characterized by massive proteinuria (the “o” in nephrotic), and nephritic syndrome is characterized by inflammation (the “-itic” in nephritic). Then at least you’ll have a shot at remembering the other features.

If you want to read more, you might want to take a look at “What causes nephritic and nephrotic syndrome?” as a sort of review of the diseases we talked about in class.

Different quiz link

Hi everyone –

Kahoot seems to be glitchy today – it hasn’t registered any results, though it has worked flawlessly in the past.

So I transferred the questions to Polldaddy, and you can take the quiz here.

I apologize for the technology glitch. If you’ve already taken the quiz on Kahoot, please either retake it on Polldaddy, or just drop me an email with your score so I can enter it.

Ugh. I will make it up to you guys!

Flowers and today’s quiz online

Hi everyone –

THANK YOU so much for the flowers!!! I had not been in my office until after class yesterday – so I just saw them now. Thank you so much – I don’t know any better words for how to express how grateful I am for your kindness and patience. What a sweet gesture – and what lovely, cheerful flowers.

Today’s quiz, as Lucy has already emailed, will have to be an online quiz. I apologize for making this last minute change. I’m hoping that it might have at least a a small benefit to you in that you have another bit of time to study for radiology.

Here is quiz 4. It is a kahoot quiz, and if you simply enter your name I will have a record of your score. I don’t believe anyone else can see your results – but if you prefer, you can use your student ID number instead. Please try to take the quiz today so we can get it done and move on 🙂

Again, thank you so, so much for all your thoughtful emails, for your patience with me and with last-minute schedule changes, and for your genuine kindness. I wish I could hug each and every one of you.

Recordings of the remaining cardiac material

Here are last year’s lecture recordings covering the cardiac material we would have covered last Wednesday:

  • This recording covers the rest of the Cardiovascular II ppt (congenital heart defects, infective endocarditis, and hypertensive heart disease), and also covers the first topic in the Cardiovascular III ppt (valvular heart disease).
  • This recording covers the rest of the Cardiovascular III ppt (cardiomyopathies and heart tumors). The cardiac stuff ends at around minute 13 (the rest of the recording covers lung pathology).

Please listen to these when you get a chance – you can listen at 1.4 or even 1.6 and still hear the information clearly because apparently I talk very slowly. This material will be covered on our next exam. Please let me know if you have any questions.

Questions on cardiac material

I got some really good questions on our cardiac material and thought I’d share them with you.

Q. Previously I thought that “pre-HTN” was a systolic BP of 140, and HTN was considered 160. Would you consider someone with a systolic over 140 to be hypertensive and put them on a preventative statin?

A. The diagnosis of hypertension is made when the average of 2 or more systolic pressure readings (on 2 or more separate visits) is greater than or equal to 140, OR when the average of 2 or more diastolic readings (on 2 or more separate visits) is greater than or equal to 90. Some sources say 3 visits; the point is, it can’t be just one reading on one visit.

Prehypertension is when a patient’s average blood pressure is between 120/80 and 140/90.

Usually, the first step after diagnosis (unless the patient has a very high blood pressure) is to make some lifestyle changes, including:

  • Eat a diet rich in potassium and fiber, and drink lots of water
  • Exercise regularly (30 minutes/day)
  • Quit smoking
  • Limit alcohol (1 drink/day for women, 2 drinks/day for men)
  • Limit sodium (less than 1,500 mg/day…the less the better!)
  • Reduce stress (meditation and yoga have been proven beneficial)
  • Stay at a healthy body weight.

If lifestyle changes don’t bring the blood pressure down to normal, then drug therapy is used.

Q. How are atherosclerotic plaques located in the body, and are they only checked for after an atherosclerotic event occurs?
A. Did you mean where? If so, they can occur anywhere in the arterial system (they almost never occur in the venous system). The most common and problematic places are the coronary arteries and the arteries serving the brain (like the carotid) – but plaques can be found anywhere: aorta, renal arteries, etc.

Generally, you only check for them once you have some indication that the patient has atherosclerosis…like symptoms of angina, or a transient ischemic attack (which is like a mini-stroke that is reversible), or something worse (like a myocardial infarction or a stroke). You can do an angiogram to see how blocked the coronary or carotid (or other) arteries are.

Q. Dr. Katz told us in physiology that a “normal” kidney would excrete all excess sodium, therefore a high sodium diet with a normal kidney was OK. Therefore, is a low sodium diet only beneficial in people with reduced renal sodium excretion associated with HTN?

A. I know – that is confusing. I am sure that Dr. Katz is right (and I also remember that from medical school): the kidney normally secretes excess sodium in the urine to maintain a normal blood sodium level. However, it is also true that low sodium diets (even in people with normal renal function) are associated with a lower risk of myocardial infarction, and high-sodium diets (even in people with normal renal function) are associated with a higher risk of myocardial infarction. I’m not sure how to reconcile these two findings – it seems that the kidney should simply excrete any excess sodium you ingest, thereby regulating blood pressure – but apparently there is more to it than that.

Interesting: cultures in which people ingest less than 50 mg of sodium a day (yes, 50!! Our guidelines say to eat less than 1,500!) have a very, very low incidence of myocardial infarction.

Cardiac stuff

There are some posts on Pathology Student about cardiac stuff that you might find helpful:

Now that we’ve started systems path, you’ll probably find the self-quizzes more useful. There’s one on cardiac pathology to start you off.

All of this is optional reading – use it only if it seems useful to you.

Serum markers of myocardial infarction

I wrote a little post on some of the more important serum markers you can use to see if someone has had a myocardial infarction.

The two most commonly used markers these days are troponins and CK (creatine kinase). Each as their own special features that make it good for diagnosing certain kinds of MIs.

You don’t have to know these in detail (although I have seen questions in dental decks…so perhaps it is a good review for boards). We have enough to cover in class without getting into too much detail.

Basically, when your cells die, they release the stuff that was inside, and you can detect that stuff in the serum. Often you’re detecting enzymes of some sort. Depending on the amount of that particular marker, and the time elapsed between injury and testing, you can get some kind of idea of whether many cells have undergone irreversible cell damage.

Remaining cardiac path material

Hi everyone –

I’m sorry I had to cancel class Wednesday. My husband’s brother died, and the wake was that day. I thought I could do both, but my husband was having a particularly difficult morning and I needed to stay with him.

So my plan is to make a short recording of the remaining slides and post it here for you to go through at your leisure. The pertinent facts are on the slides, but there are some little memory aids and some additional information I’d like to share with you. I hope to get that done by tomorrow.

Thank you, again, for your patience and understanding. You’ve all been so supportive and kind, and I’m so grateful.

Choristoma definition, bigger Kahoot, and a few other things

Hi everyone – Just a quick note to let you know that I posted a few more questions in our Kahoot (we did 1-16 in class; questions 17-27 are new). Might be a nice little review as you wrap up your studying tonight.

Also, an old copy of the Neoplasia I lecture had a typo in slide 41.  The correct slide 41 looks like this:

The old (incorrect) slide said “angiosarcoma” instead of “choristoma.” I caught it and changed it before lecture, and we talked about it in class, but I think some of you had downloaded the old copy with the typo. So I just wanted to make sure everyone has the correct version of this slide, and knows what a choristoma is. “Choristoma” sounds like a tumor, but it isn’t; it’s just normal tissue that is found in a different place – like thyroid tissue in the thymus, for example.

Finally – I posted an update to the test question numbers. I had originally included Immunologic Tests in the Immunology Overview number. I corrected it online (there are 4 questions on Immunologic Tests) but just want to be sure everyone saw the corrected number.

I will be away from my desk until around 9 pm, but will check my email after that – so if you have last minute questions feel free to ask.