Sorted By Test Name - Mayo Medical Laboratories

ANCA
9441
Clinical Information: Cytomegalovirus (CMV) is 1 of the most important infectious agents of
transplant recipients, causing significant morbidity and mortality. Direct effects of infection include fever,
leukopenia, hepatitis, colitis, and retinitis. Other manifestations of CMV infection in this population may
be more subtle and include allograft injury and loss, increased susceptibility to infections with other
organisms, and decreased patient survival (ie, indirect effects).(1) The risk of CMV disease in solid organ
allograft recipients is highest in patients who have a negative CMV serostatus prior to transplantation, and
receive an allograft from a CMV seropositive individual. Other factors, such as the type of
immunosuppressive protocol, age of the recipient, and comorbidities, may also be associated with an
increased risk of CMV disease. Available diagnostic techniques for CMV include serology (which for
transplant recipients is used to determine the pretransplant serologic status of the donor and recipient),
viral culture (conventional tube culture and shell vial cell culture), antigen detection, and nucleic acid
detection by PCR. Of these, PCR assays demonstrate the most sensitive and specific detection of CMV,
while allowing for quantitative monitoring of CMV DNA levels in peripheral blood over time. In general,
higher viral loads are associated with tissue-invasive disease, while lower levels are associated with
asymptomatic infection. However, there is a wide degree of overlap in viral load and CMV disease. For
this reason, trends in viral load over time may be more important in predicting CMV disease than a single
absolute value. Recommendations for serial monitoring of transplant recipients with quantitative CMV
PCR have been published.(6,7) In general, changes of >0.5 log(10) may represent a biologically
significant changes in virus replication.
Useful For: Early detection of cytomegalovirus (CMV) viremia Monitoring CMV disease and response
to viral therapy
Interpretation: A positive test result indicates the presence of cytomegalovirus (CMV) DNA; a
quantitative value (copies/mL) is reported. A result of "none detected" does not rule out the presence of
CMV DNA (see Cautions).
Reference Values:
None detected
Clinical References: 1. Razonable RR, Paya CV, Smith TF: Role of the laboratory in diagnosis and
management of cytomegalovirus infection in hematopoietic stem cell and solid-organ transplant
recipients. J Clin Microbiol 2002;40(3):746-752 2. Razonable RR, Brown RA, Wilson J, et al: The
clinical use of various blood compartments for cytomegalovirus (CMV) DNA quantitation in transplant
recipients with CMV disease. Transplantation 2002;73(6):968-973 3. Schaade L, Kockelkorn P, Ritter K,
Kleines M: Detection of cytomegalovirus DNA in human specimens by LightCycler PCR. J Clin
Microbiol 2000;38:4006-4009 4. Mendez JC, Espy MJ, Smith TF, et al: Evaluation of PCR primers for
early diagnosis of cytomegalovirus infection following liver transplantation. J Clin Microbiol
1998;36(2):526-530 5. Razonable RR, Brown RA, Espy MJ, et al: Comparative quantitation of
cytomegalovirus (CMV) DNA in solid organ transplant recipients with CMV infection by using two
high-throughput automated systems. J Clin Microbiol 2001;39(12)4472-4476 6. Humar A, Syndman D,
The AST Infectious Diseases Community of Practice: Cytomegalovirus in solid organ transplant
recipients. Am J Transplant 2009;9(S4):S78-S86 7. Kotton CN, Kumar D, Caliendo A, et al: International
consensus guidelines on the management of cytomegalovirus in solid organ transplantation.
Transplantation 2010;89(7):779-795
Cytoplasmic Neutrophil Antibodies, Serum
Clinical Information: Antineutrophil cytoplasmic antibodies (ANCA) can occur in patients with
autoimmune vasculitis including Wegener's granulomatosis (WG), microscopic polyangiitis (MPA), or
organ-limited variants thereof such as pauci-immune necrotizing glomerulonephritis.(1) Detection of
ANCA is a well-established diagnostic test for the evaluation of patients suspected of having autoimmune
vasculitis. ANCA react with enzymes in the cytoplasmic granules of human neutrophils including
proteinase 3 (PR3), myeloperoxidase (MPO), elastase, and cathepsin G. Antibodies to PR3 occur in
patients with WG (both classical WG and WG with limited end-organ involvement) and produce a
characteristic pattern of granular cytoplasmic fluorescence on ethanol-fixed neutrophils called the cANCA
pattern. Antibodies to MPO occur predominately in patients with MPA and produce a pattern of
perinuclear cytoplasmic fluorescence on ethanol-fixed neutrophils called the pANCA pattern.
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