Assessing Myocardial Involvement in Systemic Lupus Erythematosus Patients without Cardiovascular Symptoms by Technetium-99m-sestamibi Myocardial Perfusion Imaging: A Correlation Study on NT-proBNP.

BACKGROUND: In patients with systemic lupus erythematosus (SLE), myocardial involvement is the third leading course of death after lupus nephropathy (LN) and infections. Previous autopsy studies have demonstrated a high incidence of cardiovascular abnormalities in the myocardium. However, the patients with typical symptoms are far much fewer than expected from post-mortem examinations. OBJECTIVES: The current study aimed to evaluate the technetium-99m-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) characteristics of lupus patients without cardiovascular symptoms, and the relationships between GMPI characteristics and biochemical markers of myocardial injury, and to explore the role of GMPI in assessing myocardial involvement. METHODS: Thirty patients were studied with rest myocardial perfusion imaging, and summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were calculated automatically. Biomarkers, including N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and creatine-kinase-MB (CK-MB), were detected simultaneously. GMPI parameters, LV functions and biomarkers were compared between two NT-proBNP groups. The relationships between these parameters were studied by correlation analysis. RESULTS: SMS, STS, and glomerular filtration rate (eGFR) were the main influencing factors of NTproBNP level (p = 0.001, <0.001, 0.042, respectively). Thirteen patients with an evaluated concentration of NT-proBNP had the lower left ventricular ejection fraction (LVEF), peak filling rate (PFR), eGFR and higher levels of CK-MB (in all comparisons, p < 0.05), and SRS was the only influencing factor of NT-proBNP (p = 0.007). Within thirteen patients with SRS≥2, there was a significant correlation between SRS and NT-proBNP (p < 0.001). CONCLUSION: 99mTc-MIBI GMPI could evaluate the left ventricular function and prompt the cardiomyocyte function at the cellular level. SMS and STS were the main influencers for plasma NT-proBNP, and SRS was the independent factor for elevated NT-proBNP. This radionuclide imaging method could provide additional diagnostic information on myocardial involvement in patients with SLE.

Positron emission tomography imaging of a novel Anxa1-targeted peptide 18 F-Al-NODA-Bn-p-SCN-GGGRDN-IF7 in A431 cancer mouse models.

Annexin 1 (Anxa1) is a highly specific surface marker of tumor vasculature in the lung and prostate solid tumors. The IF7 peptide was modified with a hydrophilic linker, GGGRDN, and coupled with a new bifunctional chelating agent NODA-Bn-p-SCN. The resulting peptides (NODA-Bn-p-SCN-GGGRDN-IF7) were successfully labeled with Al18 F. The targeting characteristics of the radiolabeled peptides were evaluated in the Anxa1 positive A431 tumor model. Micro-positron emission tomography (micro-PET) imaging revealed that the A431 tumors were clearly visualized (5.74 ± 1.13%ID/g, 3.92 ± 0.78%ID/g and 1.30 ± 0.43%ID/g at 0.5, 1, and 2 h post-injection, respectively). Anxa1 binding specificity was also demonstrated by reduced tumor uptake after co-injection with excessive unlabeled GGGRDN-IF7 peptide at 30, 60, and 120 min post-injection. 18 F-Al-NODA-Bn-p-SCN-GGGRDN-IF7 might be a potential PET imaging agent for detecting Anxa1 levels in cancers due to the favorable characteristics such as convenient synthesis, specific Anxa1 targeting, and good tumor uptakes.

Synthesis and biological assessment of folate-accepted developer (99m)Tc-DTPA-folate-polymer.

A novel cancer-targetable folate-poly(2-hydroxyethyl methacrylate) (PFDH) copolymer containing DTPA segment was prepared by conventional chemical synthesis and labeled with (99m)Tc subsequently. The (99m)Tc-labled PFDH could be produced easily with high radiochemical yield of 91% and radiochemical purity of 95%. The LogP octanol-water value for the (99m)Tc-labled PFDH was -2.19 and the radiotracer was stable in phosphate-buffered saline and human serum for 2h (>95% in PBS or ∼90% in human serum). To investigate (99m)Tc-labled PFDH tumor targeting, the in vitro and in vivo stability, cell uptake, in vivo biodistribution, and SPECT imaging were evaluated, respectively. These preliminary results strongly suggest that the novel folate conjugated dendrimer maybe developed to be potential for delivery of therapeutic radionuclides.