Cryoglobulins

Question 1

What are cryoglobulins

Answer 1

Immunoglobulins that form precipitates, gels or crystals in cold temperature <37 degrees

Question 2

How are cryos reversed

Answer 2

By raising the temperature to 37 degrees

Question 3

What are the three types of cryos

Answer 3

Type 1
Type II
Type III

Question 4

What are type I cryos
(3)

Answer 4

Cryos that consist of a single monoclonal Ig usually IgG or IgM

Seen in diseases which cause monoclones such as lympho-proliferative malignancies

Cryo-property of the Ig is due to the abnormal structure of the monoclone

Question 5

What are type II cryos

Answer 5

The most clinically significant as they fix complement

A monoclonal and polyclonal component (IgG and IgM mix -> IgM is usually the monoclone while IgG is polyclonal)

Associated with collagen vascular diseasesm lymphoproliferative disorders, chronic infections, infectious mononucleosis and liver diseases

Question 6

What are type III cryos

Answer 6

Mixed polyclonal cryos
No monoclonal component
Associated with various inflammatory and infectious diseases

Question 7

What are the manifestations of cryos in situ

Answer 7

Raynaud’s phenomenon
Vascular purpura
Bleeding tendencies
Cold-induced urticaria
Distal arterial thrombosis with gangrene - rare and severe

Question 8

What manifestations are associated with type II and type III and why

Answer 8

Since they are both circulating immune complexes they may cause:
- serum sickness-like syndrome characterised by polyarthritis, vasculitis, glomerulonephritis or neurologic symptoms

Question 9

How are cryoglobulin samples taken?

Answer 9

Must be kept at 37 degrees at all times
Equipment used in phlebotomy must be at 37 degrees
Transported to lab in flask
Temperature checked immediately upon arrival in lab -> NA if below 37 degrees
Centrifuge sample at 37 degrees

Question 10

How are cryoglobulin samples analysed in lab
(3)

Answer 10

After centrifugation -> samples are separated into 3 pre-warmed gradient capillary tubes using a pre-warmed transfer pipette

Two samples are left for a week at 4 degrees while a third control is left at 37 degrees to compare to

After a week samples are checked for cryos

Question 11

What is considered a true positive cryoglobulin

Answer 11

If it re-solubilises at 37 degrees

Question 12

How are cryos typed?

Answer 12

Cryos typed using temperature treated immunofixation gels to determine the class of the cryoglobulin antibody