Session: 652. Myeloma: Pathophysiology and Pre-Clinical Studies, excluding Therapy: Poster III
Hematology Disease Topics & Pathways:
Non-Biological, Therapies, Adverse Events, Clinically relevant, pharmacology
Methods: Forty C57Bl/6 mice (12-14 weeks of age) were randomly assigned to: (i) Acute Protocol: a. Control [Normal Saline (N/S) 0.9%] and b. Cfz (8mg/kg) for two days and (ii) Sub-acute Protocol: a) Control (N/S 0.9%,) and b) Cfz (8mg/kg) for seven days. Intraperitoneal administration of N/S 0.9% and Cfz was performed at two consecutive and on alternate days for the acute and sub-acute protocols respectively. At baseline and endpoint of the experiments, systolic (SBP) and diastolic blood pressure (DBP) were measured, and subsequently mice were sacrificed for the collection of blood and renal samples. Blood samples were collected in citrate buffer for hematological/coagulation profiling [prothrombin time (PT) and INR estimation] and for cleaved Von Willebrand Factor (cl. VWF) immunoblotting assessment as well as for blood testing of white blood cells (WBCs) and platelets. Renal samples underwent histological proteomic and molecular analyses.
Results: SBP and DBP were found to be elevated in Cfz group only in the sub-acute protocol compared to control (SBP: 78.5±2.0 vs 68.2±0.7, p<0.01 and DBP: 104.1±2.3 vs 97.4±2.4, p<0.05, respectively). Neutrophil count in the whole blood was elevated both in the acute and sub-acute protocols, while platelet count was decreased in the acute protocol and restored after sub-acute Cfz administration. Mice presented a thrombotic phenotype characterized by increased PT and INR and decreased cl. VWF after acute Cfz treatment, and a hemorrhagic phenotype with restored cl. VWF after sub-acute Cfz administration. However, the presence of TMA was not confirmed by histological evaluation of the kidneys in any of the protocols. Nonetheless histological evaluation of the kidneys revealed inflammation of the perirenal adipose tissue only in the sub-acute protocol. Proteomic analysis presented that proteasome regulation, metabolism and transport of organic anion processes are affected by Cfz administration. Molecular analysis of the renal tissue showed that Cfz induced an increase in the inducible nitric oxide synthase (iNOS) and microtubule-associated proteins 1A/1B light chain 3B (LC3-B) expression and a decreased AMPKα phosphorylation. Moreover, RT-PCR analysis of the renal samples revealed that collecting duct ion channels epithelial Na+ channel (ENaC), Na+/K+/ATPase and urea transporter 1 (UTA-1) mRNA levels were increased in Cfz group.
Conclusion: Sub-acute Cfz treatment establishes a renal-derived hypertensive phenotype and a circulating inflammatory phenotype as indicated by the increased neutrophil and WBCs count in the blood. TMA does not seem to be implicated with the observed phenotype in vivo as investigated molecularly and histologically. Cfz-induced dephosphorylation of AMPKα and the subsequent dysregulation of the collecting duct renal ion channel homeostasis is found to be responsible for the observed effect. Therefore, Cfz seems to induce hypertension by a dysregulation of water-ion re-absorbance leading to increased cardiac preload. The latter comes in agreement with clinical data showing that some Cfz-treated patients present with fluid retention, which can be attributed to the aforementioned renal effects of the drug.
Disclosures: Efentakis: Amgen: Research Funding. Kastritis: Amgen: Consultancy, Honoraria, Research Funding; Genesis Pharma: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria. Dimopoulos: BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Speakers Bureau; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Personal fees, Research Funding, Speakers Bureau. Andreadou: Amgen: Research Funding. Terpos: Amgen: Honoraria, Research Funding; Genesis pharma SA: Honoraria, Other: travel expenses , Research Funding; Janssen: Honoraria, Research Funding; Takeda: Honoraria, Other: travel expenses , Research Funding; Celgene: Honoraria; Sanofi: Honoraria; BMS: Honoraria.