Sorted By Test Name - Mayo Medical Laboratories

FBMT
80601
FXYLP
90359
XX/XY in Opposite Sex Bone Marrow Transplantation, FISH
Clinical Information: Bone marrow transplantation (BMT) is an important treatment for patients
with certain malignant hematologic disorders and hereditary conditions. Conventional cytogenetic studies
can identify chromosome abnormalities, establish the proportion of donor and recipient metaphase cells to
monitor the success of BMT engraftment, and detect residual disease after treatment. However,
conventional chromosome studies are usually done on only 20 to 30 metaphase cells and may be less
sensitive than other methods. When the donor and recipient are of opposite sex, the donor and recipient
cells can be readily identified by their sex chromosome complement. FISH using probes for the X and Y
chromosomes can be used to estimate the proportion of donor and recipient interphase cells in bone
marrow or peripheral blood. Monitoring the proportion of host and recipient cells over time also may be
useful to identify significant clinical changes. This method is easy, objective, and permits analysis of large
numbers of cells. Our experience also suggests that FISH is economical, rapid, and accurate.(1) FISH
specimens are preprocessed in the same manner as chromosome analysis specimens. If FISH results or
clinical circumstances suggest the possibility of disease relapse, chromosome studies can be performed on
the same specimen to determine if an abnormal clone is present. To maximize the cost-effectiveness of
FISH and chromosome analysis, we recommend conventional chromosome analysis prior to BMT to
establish the karyotype of the malignant cell line. After BMT, the use of FISH alone on either bone
marrow or peripheral blood may be sufficient to monitor the success of the engraftment.
Useful For: Evaluating engraftment success by determining the proportion of donor and recipient
interphase cells present in opposite sex bone marrow transplant recipients Monitoring the proportion of
host and recipient cells over time may be useful to identify significant clinical changes
Interpretation: Specimens from females that have >0.6% XX interphase cells have residual XX host
cells. Specimens from males that have >0.3% XY interphase cells have residual XY host cells. The results
of both conventional chromosome studies and FISH are best interpreted when findings before and after
bone marrow transplantation are compared. Our reports include a summary of the percentage of host and
donor cells present in prior studies from the same patient.
Reference Values:
< or =0.3% cells with XY signals for pretransplant females
< or =0.6% cells with XX signals for pretransplant males
Clinical References: Dewald GW, Schad CR, Christensen ER, et al: Fluorescence in situ
hybridization with X and Y chromosome probes for cytogenetic studies on bone marrow cells after
opposite sex transplantation. Bone Marrow Transplant 1993;12:149-154
Xylene Exposure Panel, Urine
Reference Values:
Reporting limit determined each analysis
Creatinine (mg/L)
U.S. Population (10th – 90th percentiles, median)
All participants:
335 - 2370 mg/L, median: 1180 (n=22,245)
Males:
495 - 2540 mg/L, median: 1370 (n=10,610)
Females:
273 - 2170 mg/L, median 994 (n=11,635)
Methylhippuric Acid (g/L)
Synonym(s): Methylhippurate; Xylene Metabolite
Exposure to 100 ppm xylene in air for 8 hours,
produced urine concentrations of approximately 3 g/L.
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