Cold agglutinin disease

Question 1

Treatment

Answer 1

• Cold avoidance
  *Rituximab or BR
  NOT IVIG, splenectomy, or steroids

Question 2

Direct antiglobulin test result in cold agglutinin disease

Answer 2

Positive for C3

Question 3

lab features on
Peripheral smear —
DAT features
CBC features

Answer 3

• agluttinated erythrocytes on peripheral smear
• positive direct coombs with C3 on erythrocytes
• positive hemolysis labs + can have very high MCV (
  agglutinated erythrocytes)

Question 4

antibody involved

Answer 4

IgM (think snowflake)

Question 5

Pathophys

Answer 5

• IgM antibodies directed against erythrocyte antigens, resulting in complement fixation and intravascular hemolysis

Question 6

common finding on smear in cold agluttinin disease

Answer 6

RBC agglutination

Question 7

RBC antigen associated with cold agglutinin disease

Answer 7

I

Question 8

Where RBC destruction takes place in cold agglutinin disease

Answer 8

Liver, not in the spleen (this is why splenectomy is not indicated)

Question 9

management of severe anemia in cold agglutinin disease

Answer 9

IVIG vs. plasmapheresis (rituximab has delay in effect)

Question 10

what are cold agglutinins

Answer 10

IgM antibodies that recognize RBC antigens at temperatures below the normal core body temperature. They cause RBC agglutination and extravascular hemolysis.

Question 11

other precipitants of cold agglutinin hemolysis

Answer 11

• infections (usually occurs a couple weeks after the onset of the primary infection, diminishes as infection resolves, and resolves afterward)

Question 12

management of cold aglutinan disease for lymphoma and infection related

Answer 12

IF non infection or lymphoma related, Rituximab (60% response rate) vs. bendamustine/rituximab (treat both lymphoma and cold agglutinin disease. there is a clonal source of cold agglutinin production)
IF infection related, observation (typically self limiting) and treat infection (eg azithromycin for mycoplasma)