Cryoglobulin, Serum

Specimen requirement Adult patient:

Special clotted blood tube for cryoglobulin (in thermos flask)

Minimum blood volume: 10 mL
Paediatric patient:

Special clotted blood tube for cryoglobulin (in thermos flask)

Minimum blood volume: 3 mL
Authorisation code required No
24 Hr available service No
Precaution

Protocol for Cryoglobulin Test

  1. Please arrange with Chemical Pathology staff (Ext. 2363, Office hours: 09:00-17:00, Monday - Friday) for a cryoglobulin kit which is kept inside a thermo flask.

  2. There are one pre-warmed syringe and one plain bottle inside the thermos flask with warm sand.  Label the pre-warmed plain bottle with patient's gum label.

Content of Tin Foil Bag

Pocket 1:

1. Instruction (open pocket of zipbloc bag)

2. Syringe (inside zipbloc bag)

 

 Pocket 2:

1. 10 mL clotted blood tube

 
  1. Perform venipuncture with the pre-warmed syringe and put at least 10 mL blood into the labelled plain bottle without any spillage. Adequate blood volume is required to maximise the sensitivity of cryoglobulin detection.
     
  2. Close the thermos flask tight immediately.
     
  3. Send the flask to Chemical Pathology Laboratory at once.
     
  4. Any delay in specimen transport with sand bath temperature of  less than 36 °C will be rejected.

Hints: Keep the plastic bag inside the thermos flask allowing easy replacement of specimen bottle back into the sand bath.

* Strict temperature control is a prerequisite for the investigation of cryoglobulins because of their temperature-dependent nature. Overheating of specimens leads to protein denaturation while cooling of specimens to below body temperature risks cryoprecipitation before laboratory processing.
Method Serum is stored at 4 °C for 72 hours and inspected for precipitate during this period. For all positive cases, quantitation of cryoglobulin will be performed and results reported in g/L, while typing of the cryoglobulin by immunofixation will be performed for new positive cases only.
Reference interval Normal: negative
Clinical indication

Investigation of cold related symptoms, suspected immune complex mediated disease. The disorder should be considered in the presence of one or more of renal impairment, rash and peripheral neuropathy.
Result interpretation

Cryoglobulins precipitate at 4 °C and re-dissolve at 37 °C.

The presence of cryoglobulin may be secondary to an underlying infection (especially hepatitis C), lymphoma, myeloma or immune complex disorder (e.g. SLE).

Once cryoglobulinaemia has been diagnosed, all the blood specimens sent for protein testing, including Ig patterns, serum protein electrophoreisis, cryoglobulins, and rheumatoid factor must be sent using temperature precautions to avoid falsely low results due to cryoprecipitations.
Measurement of uncertainty See table.
Frequency of measurement Daily