A patient with type ICD36 deficiency whose myocardium accumulated I-123-BMIPP after 4 years

A 73-year-old man with aortic regurgitation was examined by I-123-alpha -me thyl-p-iodophenylpentadecanoic acid (BMIPP) myocardial single photon emissi on computed tomography (SPECT) in 1995. Myocardial accumulation was not evi dent on either the early or the delayed image obtained 15 minutes and 3 hou rs, respectively, after injecting I-123-BMIPP. Flow cytometric analysis of CD36 expression in monocytes and platelets identified a type I CD36 deficie ncy. The patient was hospitalized for severe heart failure in 1999. Upon ad mission, the cardiothoracic ratio on chest Xrays was 73%, and the left vent ricular end-diastolic diameter on echocardiograms was enlarged to 77 mm. On the second day, we performed I-123-BMIPP myocardial SPECT. Myocardial accu mulation was evident in the delayed, but not in the early image. We repeate d I-123-BMIPP myocardial SPECT on the 10th day after admission. Myocardial accumulation was evident on both early and delayed images. Tc-99m-tetrofosm in myocardial SPECT was immediately performed after I-123-BMIPP myocardial SPECT to distinguish myocardial from pooling images in the left ventricle, but, because the images from both 99mTc-tetrofosmin and I-123-BMIPP myocard ial SPECT were idential, we considered that the 123I-BMIPP myocardial SPECT images reflected the actual myocardial condition. The CD36 molecule transports long-chain fatty acid (LCFA) on the myocardial membrane, but I-123-BMIPP scintigraphy does not show any myocardial accumu lation in patients with type I CD36 deficiency, indicating that myocardial LCFA uptake occurs through CD36 on the human myocardial membrane. Even thou gh our patient had type I CD36 deficiency, BMIPP was uptaken by the myocard ium during heart failure, suggesting a variant pathway on the human myocard ial membrane for LCFA uptake.