Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

MDCG
86880
MORP
83132
complement can be demonstrated by the direct antiglobulin (Coombs) test.
Useful For: Detecting complement bound to RBC Investigation of hemolytic anemia
Interpretation: The presence or absence of red cell-bound complement is used in conjunction with
other testing and clinical data to aid in the characterization of hemolysis as immune-mediated. Possible
causes include autoimmune hemolytic anemia, drug-induced hemolysis, hemolytic disease of the
newborn, and alloimmune reactions to recently transfused RBC.
Reference Values:
Negative
If positive, reaction is graded (positive 1+ to 4+).
Monospecific Direct Coombs IgG, Blood
Clinical Information: IgG antibody may be present on patient or donor (transfused) RBCs and may
cause hemolysis. The antibodies may be directed against self-antigens (autoimmune hemolysis), maternal
antigens (hemolytic disease of the newborn), donor antigens (eg, alloimmune transfusion reaction), or
drugs. The presence of in vivo coating of RBC with IgG can be demonstrated by the direct antiglobulin
(Coombs) test.
Useful For: Detecting antibodies bound to RBC Investigation of hemolytic anemia
Interpretation: The presence or absence of IgG is used in conjunction with other testing and clinical
data to aid in the characterization of Hemolysis as immune-mediated. Possible causes include
autoimmune hemolytic anemia, drug-induced hemolysis, hemolytic disease of the newborn, and
alloimmune reactions to recently transfused RBC.
Reference Values:
Negative
If positive, reaction is graded (positive 1+ to 4+).
Morphine, Unconjugated, Serum
Clinical Information: Morphine interacts primarily with mu-opioid receptor to mediate its effects,
but also shows some affinity for kappa-opioid receptor.(1) Its major metabolites are glucuronide
conjugates including: inactive morphine-3-glucuronide (M3G, approximately 60%), active
morphine-6-glucuronide (M6G, approximately 10%), and a small amount of
morphine-3,6-diglucuronide.(2, 3) The enzyme UDP-glucuronosyltransferase-2B7 (UGT2B7) is primarily
responsible for morphine glucuronidation.(2)
Useful For: Monitoring morphine therapy Routine drug monitoring is not indicated in all patients.
Compliance monitoring is indicated in patients who are being treated for acute pain requiring excessive
dose. Assessing toxicity
Interpretation: The minimal effective peak serum concentration of unconjugated morphine for
analgesia is 20 ng/mL. Peak therapeutic serum concentrations of 70 ng/mL to 450 ng/mL occur 30
minutes after intravenous dose, 1 hour after intramuscular or subcutaneous dose, or 2 hours after oral
dose. Patients continuously administered morphine develop tolerance; they can tolerate serum
concentrations up to 1,500 ng/mL. Death may be associated with serum total morphine >700 ng/mL in the
nontolerant subject.(4)
Reference Values:
Therapeutic: 70-450 ng/mL
Tolerant patients: 700 ng/mL
Clinical References: 1. Gutstein HB, Akil H: Opioid analgesics. In Goodman & Gilman's The
Pharmacological Basis of Therapeutics, 11th edition. Edited by LL Brunton, JS Lazo, KL Parker. New
Current as of January 3, 2013 2:22 pm CST 800-533-1710 or 507-266-5700 or MayoMedicalLaboratories.com Page 1238