CRYPTOCOCCUS LATEX AGGLUTINATION TEST

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The Cryptococcal Antigen Latex Agglutination System is a qualitative and semi-quantitative test system for the detection of capsular polysaccharide antigens of Cryptococcus neoformans. Latex agglutination test has both diagnostic and prognostic value since progressive disease is usually accompanied by increasing antigen titers. Declining titers are usually associated with clinical improvement, with or without therapy. Inadequate therapy is indicated by stationary or rising titers on subsequent, sequential specimens. Cryptococcal antigen in the body fluids of the untreated patient indicates active infection. However, in some treated patients, titers remain positive at low levels for extended periods during which the organism can no longer be demonstrated.

• Latex Agglutination
• Serum specimens are pre-treated with pronase and heat inactivated prior to testing.
• CSF specimens are heat inactivated prior to testing.

The result is not intended to be used as the sole means for clinical diagnosis or patient management decisions.

• CSF titers of 1:4 or less are presumptive evidence of central nervous system infection by C. neoformans; additional follow-up and culture are strongly recommended. CSF titers of 1:8 or greater from patients with meningitis strongly suggest infection by C. neoformans. However, diagnosis should be confirmed by identification of the organism from culture or by microscopic examination of the specimen.
• A negative test does not preclude diagnosis of cryptococcosis, particularly if only a single specimen has been tested and the patient shows symptoms consistent with cryptococcosis.
• A false positive reaction due to the antigen of Trichosporon beigelii, which cross reacts with the C. neoformans capsular polysaccharide has been reported.
• High protein levels can cause interference.

• Serum: Separated from the clot, in a leak-proof container.
• CSF: Submit CSF in a sterile leak-proof container.

Serum/CSF: 0.25 mL

Refrigerated/Frozen: 60 days

• Specimen types other than serum or CSF.
• Samples shipped at ambient temperature.

Refrigerated/Frozen

Ship on dry ice  for next day service. Frozen ice packs may be substituted if sample is shipped the day of collection. Monday-Friday delivery

• Serum/CSF: Same day

*Positive results will reflex to a titer.

**Test Set up: Samples for Antigen testing received by 10:30AM will have same day test set up. Positive samples may require confirmation which could extend turnaround time. Serum & CSF specimens are pretreated to improve sensitivity, which can add one day to turnaround time.

None detected