Low-density lipoprotein (LDL) distribution shown by 99mtechnetium-LDL imaging in patients with myeloproliferative diseases.
OBJECTIVE
To image and identify by noninvasive methods the sites of low-density lipoprotein (LDL) catabolism in patients with myeloproliferative disease in whom chronic hypocholesterolemia was previously reported.


METHODS
The 99mTechnetium-LDL (Tc-LDL) distribution in patients with myeloproliferative diseases was compared with that in normal subjects. The Tc-LDL distribution was also compared with the distribution and organ uptake of a macrophage-seeking radiotracer. 99mTc-sulfur colloid (Tc-SC).


METHODS
Major metropolitan referral center and institutional practice.


METHODS
Three normal subjects, two patients with polycythemia vera, two with post polycythemia myeloid metaplasia, and one with agnogenic myeloid metaplasia. The patients were being managed with hydroxyurea or phlebotomy.


METHODS
Ten mCi of Tc-LDL (homologous) was injected intravenously.


RESULTS
Gamma camera images of Tc-LDL biodistribution and organ uptake were obtained 4 hours after injection of the tracer. In normal subjects, the Tc-LDL was predominantly taken up by the liver, with relative nonvisualization of spleen and central or peripheral marrow. Patients with myeloproliferative disease showed marked splenic uptake of Tc-LDL. Peripheral bone marrow uptake extended to the lower tibia in two patients with post-polycythemia myeloid metaplasia. Splenic and bone marrow uptake paralleled that of Tc-SC. Hypercellularity of central and peripheral marrow at the sites of Tc-LDL uptake was confirmed by biopsy specimens. The Tc-LDL uptake, however, was not correlated with collagen fibrosis.


CONCLUSIONS
These results indicate that spleen and bone marrow are sites of LDL catabolism in patients with myeloproliferative disease and suggest the role of macrophages in the hypocholesterolemia and accelerated LDL catabolism of myeloproliferative disease.
Vallabhajosula
S
S
Mount Sinai School of Medicine, New York, New York.
Gilbert
H S
HS
Goldsmith
S J
SJ
Paidi
M
M
Hanna
M M
MM
Ginsberg
H N
HN
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006995:Hypobetalipoproteinemias / Q000378:metabolism*; D007009:Hypolipoproteinemias / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000493:pharmacokinetics*; D008264:Macrophages / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000502:physiology; D009196:Myeloproliferative Disorders / Q000378:metabolism*; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; D013667:Technetium; D013671:Technetium Tc 99m Sulfur Colloid
D008077:Lipoproteins, LDL; D009942:Organometallic Compounds; D015609:Organotechnetium Compounds; C058312:technetium Tc 99m low-density lipoprotein; D013671:Technetium Tc 99m Sulfur Colloid; D013667:Technetium