Thread by @DrChadJohr

My #Sjögren's patients often wonder about their lab results:

“What is SPEP & hypergammaglobulinemia?”

Let’s discuss…

1/14 (sorry, this one is a bit long!)

The other day I mentioned that low C4 complement levels are associated w/ lymphoma development & poor prognosis in Sjogren’s:

twitter.com/hashtag/Sj%C3%…

2/14

We also learned that having low C4 complement levels in someone being evaluated for possible #Sjögren's could be predictive for the diagnosis (“classification”, technically speaking) 2-3 years later even w/ a negative initial evaluation:

doi.org/10.1002/acr.23…

3/14

If you took a look at that article, you might have noticed that the other predictive factor for the classification of #Sjögren's in those w/ objective dryness but negative initial evaluation is the presence of HYPERGAMMAGLOBULINEMIA. That’s a mouthful! Let’s dig in…

4/14

Blood is composed of cells & fluid. The fluid (w/out the cells) is called serum. Proteins in the blood reside mainly in the serum.

Serum proteins can sometimes be abnormal. How can we tell?

5/14

One way of looking into serum protein abnormalities is to put a drop of serum onto one end of a specialized flat stick and then apply an electric current to it.

The electric current makes the serum proteins move from one end of the stick towards the other.

6/14

The smaller the size of the protein, the farther along the stick it will move.

So the smallest proteins move all the way to the far end of the stick, the medium sized ones move to the middle, and the largest ones don’t travel very far.

Make sense so far?

7/14

This separates all the different protein types in our serum. Now that they are separated, they can be analyzed.

Each group of proteins (separated by size) can be measured on a graph. The greater the amount of protein in each group, the higher the level on the graph.

8/14

Visually this looks like waves. Each group of proteins makes a wave. The greater the amount of proteins in the group, the greater the size of the wave. Each wave is given a name using the Greek alphabet: alpha, beta, *gamma*, etc.

9/14

Antibodies (which are proteins) are all similar in size & tend to reside in the GAMMA wave of this graph. When our immune system is hyperactive, we sometimes develop more antibodies than usual. This leads to a larger gamma wave.

So now let’s put this together…

10/14

Hyper = larger/bigger
gamma = the wave w/ antibodies
globulin = Protein (antibodies are “immunoglobulins”)
emia = blood (like, “anemia”)

So that, in a nutshell, is hypergammammaglobulinemia.

11/14

By the way, the technical name for this "electric current test" is *electrophoresis*.

So now you understand what “SPEP” stands for:

Serum
Protein
Electro
Phoresis

We order an SPEP when looking for protein abnormalities in the blood such as hypergammaglobulinemia.

12/14

So in patients who have objective evidence of dryness but negative SSA & lip biopsy, I consider ordering an SPEP & C4 level.

If C4 is low or SPEP reveals hypergammaglobulinemia, the patient is more likely to be classified as Sjogrens on repeat testing in 2-3 yrs.

13/14

I especially find this helpful if the lip biopsy is negative but not completely normal (focus score less than 1 but greater than zero).

That’s all for now. Please consider retweeting the first tweet & thanks for reading!

14/14

That was the wrong link. Sorry about that. I hope this one works:

https://twitter.com/DrChadJohr/status/1532924520071188480?ref_src=twsrc%5Etfw