Sorted By Test Name - Mayo Medical Laboratories

EVERO
60537
83656
Clinical References: Homburger HA: Allergic diseases. In Clinical Diagnosis and Management by
Laboratory Methods. 21st edition. Edited by RA McPherson, MR Pincus. New York, WB Saunders
Company, 2007, Chapter 53, Part VI, pp 961-971
Everolimus, Blood
Clinical Information: Everolimus is an immunosuppressive agent derived from sirolimus
(rapamycin). Both drugs function via inhibition of mTOR signaling, and share similar pharmacokinetic
and toxicity profiles. Everolimus has a shorter half-life than sirolimus, which allows for more rapid
achievement of steady-state pharmacokinetics. Everolimus is extensively metabolized, primarily by
CYP3A4, thus its use with inducers or inhibitors of that enzyme may require dose adjustment. The most
common adverse effects include hyperlipidemia, thrombocytopenia, and nephrotoxicity. Everolimus is
useful as adjuvant therapy in renal cell carcinoma and other cancers. It recently gained FDA approval for
prophylaxis of graft rejection in solid organ transplant, an application which has been accepted for years
in Europe. The utility of therapeutic drug monitoring has not been established for everolimus as an
oncology chemotherapy; however, measuring blood drug concentrations is common practice for its use in
transplant. Therapeutic targets vary depending on the transplant site and institution protocol. Guidelines
for heart and kidney transplants suggest that trough (immediately prior to the next scheduled dose) blood
concentrations between 3 to 8 ng/mL provide optimal outcomes.
Useful For: Management of everolimus immunosuppression in solid organ transplant
Interpretation: Therapeutic targets vary by transplant site and institution protocol. Heart and kidney
transplant guidelines suggest a therapeutic range of 3 to 8 ng/mL. Measurement of drug concentrations in
oncology chemotherapy is less common, thus no therapeutic range is established for this application.
Reference Values:
3-8 ng/mL
Clinical References: 1. Eisen HJ, Tuzcu EM, Dorent R, et al: Everolimus for the prevention of
allograft rejection and vasculopathy in cardiac-transplant recipients. N Engl J Med 2003;349(9):847-858
2. Kovarik JM, Beyer D, Schmouder RL: Everolimus drug interactions: application of a classification
system for clinical decision making. Biopharm Drug Dispos 2006;27(9):421-426 3. Rothenburger M,
Zuckermann A, Bara C, et al: Recommendations for the use of everolimus (Certican) in heart
transplantation: results from the second German-Austrian Certican Consensus Conference. J Heart Lung
Transplant 2007;26(4):305-311 4. Sanchez-Fructuoso AI: Everolimus: an update on the mechanism of
action, pharmacokinetics and recent clinical trials. Expert Opin Drug Metab Toxicol 2008;4(6):807-819
Ewing Sarcoma (EWS), 22q12 (EWSR1) Rearrangement, FISH,
Tissue
Clinical Information: Ewing sarcoma (EWS)/primitive neuroectodermal tumors (PNET) are
members of the small, round cell group of tumors that are thought to originate in cells of primitive
neuroectodermal origin with variable degrees of differentiation. The small, round cell group of tumors
also includes rhabdomyosarcomas, desmoplastic small, round cell tumors, and poorly differentiated
synovial sarcomas. Although immunohistochemical markers can be helpful in the correct diagnosis of
these tumors, recent molecular studies have shown the specificity of molecular markers in differentiating
specific subtypes of small, round blue-cell tumors. Accurate diagnosis of each tumor type is important for
appropriate clinical management of patients. Ewing tumors are characterized cytogenetically by
rearrangements of the EWSR1 gene at 22q12 with FLI1 at 11q24 (t[11;22]) or ERG at 21q22 (t[21;22]) in
85% and 5% to 10% of Ewing tumors, respectively. Less than 1% of cases may have other fusion partners
such as ETV1 at 7p22, E1AF at 17q12, or FEV at 2q33. Detection of these transcripts by reverse
transcriptase-PCR (RT-PCR) (#83363 Ewingâ€s Sarcoma/Primitive Neuroectodermal Tumors
[ES/PNET] by Reverse Transcriptase PCR [RT/PCR], Paraffin), which allows specific identification of
the t(11;22) and the t(21;22), has greatly facilitated the diagnosis of Ewingâ€s tumors. However, if the
quality of the available RNA is poor, the results are equivocal, or if a rare translocation partner is present,
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