discussion 37

[Anonymous]

Ro and La positive pt, how about his HCO3- and K+?

[Anonymous]

hi mimi, what are "Ro and La "?

[Anonymous]

Chronic renal failure leading to metabolic acidosis (low HCO3 ) and Hyperkalemia

[Anonymous]

Ro--- anti-SS-A
La--- anti-SS-B

try again......

[Anonymous]

Excellent correlation with yesterdays AG discussion Mimi!
This question tests your knowledge of a couple of different areas and your ability to correlate them to get your answer.

First you need to realize that "Ro" and "La" are discriptions of anti-SS-A and B respectively, which are both markers for Sjogren's syndrome. Then you need to remember that this syndrome causes distal renal tubualr acidosis. And finally, you need to know that distal type I renal tubular necrosis is one of the main causes of normal AG metabolic acidosis.

From yesterdays discussions, you'll remember that the AG is normal because the lost HCO3- is replaced by Cl-. So as guest said, the HCO3 will be low and the Cl- will be high. This will give a normal hyperchloremic AG met acidosis.

AG = Na - (Cl + HCO3)


ref: kaplan notes by goljan sec 1 pgs 82-84, sec 2 pg 221

[Anonymous]

Great step 1, you are on the right track to the answer:

HCO3- is low, as you said, which is correct. (metabolic acidosis from type I RTA in sjogren syndrome.)

As it is type I RTA in SS, please read RTA in renal chapter, you will find serum K+......

[Anonymous]

Rushing through questions and missing important information is my downfall I overlooked K+ in your question

In renal tubular acidosis, all will have dec K+ except type 4. Since this is type 1, it will have dec K+. Dysfunctional aldosterone mediated H+/K+ ATPase pump in the collecting ducts.

[Anonymous]

yeal, you got it !!!