Drugs that interfere with SPEP

Question 1

IV Immunoglobulin (IVIG)

Answer 1

Can cause a broad polyclonal gamma region increase or even a pseudomonoclonal band.

Question 2

Monoclonal Antibody Therapies (e.g., Rituximab, Daratumumab)

Answer 2

May create an extra band in the gamma region that mimics an M-spike.

Question 3

Erythropoietin (EPO)

Answer 3

Can induce an increase in gamma globulins.

Question 4

Corticosteroids

Answer 4

Increase albumin synthesis, leading to higher albumin levels.

Question 5

NSAIDs, Phenytoin, and Valproic Acid

Answer 5

Can bind albumin and cause an apparent decrease in free albumin levels.

Question 6

Estrogen (Oral Contraceptives, Hormone Replacement Therapy)

Answer 6

Increases alpha-2 globulins (haptoglobin, ceruloplasmin).

Question 7

Steroids & Androgens

Answer 7

Can reduce transferrin (beta globulin), affecting the beta region.

Question 8

Beta-blockers, ACE Inhibitors

Answer 8

Can mildly increase alpha-1 and alpha-2 globulins.

Question 9

Chronic Opioid Use

Answer 9

May increase alpha-2 globulin levels

Question 10

Contrast Media (IV Contrast for CT/MRI)

Answer 10

Can produce an artificial band in the beta or gamma region.

Question 11

Heparin

Answer 11

Can cause protein precipitation, leading to irregular bands.