Addressing the ‘hypoxia paradox’ in severe COVID-19: literature review and report of four cases treated with erythropoietin analogues

Background: Since fall 2019, SARS-CoV-2 spread world-wide, causing a major pandemic with estimated ~ 220 million subjects affected as of September 2021. Severe COVID-19 is associated with multiple organ failure, particularly of lung and kidney, but also grave neuropsychiatric manifestations. Overall mortality reaches > 2%. Vaccine development has thrived in thus far unreached dimensions and will be one prerequisite to terminate the pandemic. Despite intensive research, however, few treatment options for modifying COVID-19 course/outcome have emerged since the pandemic outbreak. Additionally, the substantial threat of serious downstream sequelae, called ‘long COVID’ and ‘neuroCOVID’, becomes increasingly evident. Main body of the abstract: Among candidates that were suggested but did not yet receive appropriate funding for clinical trials is recombinant human erythropoietin. Based on accumulating experimental and clinical evidence, erythropoietin is expected to (1) improve respiration/organ function, (2) counteract overshooting inflammation, (3) act sustainably neuroprotective/neuroregenerative. Recent counterintuitive findings of decreased serum erythropoietin levels in severe COVID-19 not only support a relative deficiency of erythropoietin in this condition, which can be therapeutically addressed, but also made us coin the term ‘hypoxia paradox’. As we review here, this paradox is likely due to uncoupling of physiological hypoxia signaling circuits, mediated by detrimental gene products of SARS-CoV-2 or unfavorable host responses, including microRNAs or dysfunctional mitochondria. Substitution of erythropoietin might overcome this ‘hypoxia paradox’ caused by deranged signaling and improve survival/functional status of COVID-19 patients and their long-term outcome. As supporting hints, embedded in this review, we present 4 male patients with severe COVID-19 and unfavorable prognosis, including predicted high lethality, who all profoundly improved upon treatment which included erythropoietin analogues. Short conclusion: Substitution of EPO may—among other beneficial EPO effects in severe COVID-19—circumvent downstream consequences of the ‘hypoxia paradox’. A double-blind, placebo-controlled, randomized clinical trial for proof-of-concept is warrante

Relationships between hypoxia markers and the leptin system, estrogen receptors in human primary and metastatic breast cancer: effects of preoperative chemotherapy

<p>Abstract</p> <p>Background</p> <p>Tumor hypoxia is marked by enhanced expression of hypoxia-inducible factor-α (HIF-1α) and glucose transporter-1 (Glut-1). Hypoxic conditions have also been associated with overexpression of angiogenic factors, such as leptin. The aim of our study was to analyze the relationships between hypoxia markers HIF-1α, Glut-1, leptin, leptin receptor (ObR) and other breast cancer biomarkers in primary and metastatic breast cancer in patients treated or untreated with preoperative chemotherapy.</p> <p>Methods</p> <p>The expression of different biomarkers was examined by immunohistochemistry in 116 primary breast cancers and 65 lymph node metastases. Forty five of these samples were obtained form patients who received preoperative chemotherapy and 71 from untreated patients.</p> <p>Results</p> <p>In primary tumors without preoperative chemotherapy, HIF-1α and Glut-1 were positively correlated (p = 0.02, r = 0.437). HIF-1α in primary and metastatic tumors without preoperative therapy positively correlated with leptin (p < 0.0001, r = 0.532; p = 0.013, r = 0.533, respectively) and ObR (p = 0.002, r = 0.319; p = 0.083, r = 0.387, respectively). Hypoxia markers HIF-1α and Glut-1 were negatively associated with estrogen receptor alpha (ERα) and positively correlated with estrogen receptor beta (ERβ). In this group of tumors, a positive correlation between Glut-1 and proliferation marker Ki-67 (p = 0.017, r = 0.433) was noted. The associations between HIF-1α and Glut-1, HIF-1α and leptin, HIF-1α and ERα as well as Glut-1 and ERβ were lost following preoperative chemotherapy.</p> <p>Conclusions</p> <p>Intratumoral hypoxia in breast cancer is marked by coordinated expression of such markers as HIF-1α, Glut-1, leptin and ObR. The relationships among these proteins can be altered by preoperative chemotherapy.</p

The effect of humic-fatty acid preparation on selected haematological and biochemical serum parameters of growing rabbits

In this study, we assessed the effect of a humic-fatty acid preparation (HFA) used in rabbit feed on certain haematological and biochemical serum parameters (the lipid profile and the Ca, P and Fe contents). A higher RBC, HGB and HCT values were observed in the groups that were given HFA. An increase in Fe concentrations were also noted. The total and LDL cholesterol were lower in the groups which received HFA than in the control group