This is an "off-label" post, as it doesn't directly address hemostasis, however, on April 6, Ari Elman, MD, Hem-Onc at Greater Baltimore Medical Center wrote,
"As I'm sure you have, I have been reading report after report regarding these patients and trying to find some understanding of the pathophysiology that might help in treatment. A very interesting point was related to the possibility that the virus might actually bind to one of the hemoglobin subunits which might explain the severe hypoxia, but lack of symptoms. Many of us have seen patients walking around with just slight shortness of breath, but when checked, their oxygenation is in the low 80s, and they decompensate quickly with any minimal exertion. A physician in a COVID online group suggests an interaction with hemoglobin (HGB
), paraphrased as follows:
HGB has four cooperative binding sites. The sigmoid oxygen dissocation curve reflects the cumulative cooperativity among the sites. If the virus binds the beta-1 subunit, the curve shifts so that less oxygen is delivered to the tissue. The binding could actually change the shape of the curve. So do not let your patients walk to the bathroom and increase their oxygen requirement.
This was new to me, so I ran it by my friend, colleague, and RBC metabolism expert Kathryn Doug, PhD, Michigan State University who then contacted her colleague, Rosemarie Brichta. Brichta located a rigorously scientific pre-pub manuscript, Liu W, Ki H, COVID-19 attacks the 1-beta chain of hemoglobin and captures the porphyrin to inhibit human heme metabolism. The article elegantly demonstrates how envelope proteins of the virus may bind homologous strands in porphyrin, the iron-bearing compound at the center of the heme O2 pocket. Liu is from the School of Computer Science and Engineering, Sichuan University of Science & Engineering, Zigong, and Li from the School of Life Science and Food Engineering, Yibin University, Yibin, China. I will hope to post this article upon publication.
This post is an attempt to learn if others are seeing these distinctive symptoms, and if hydroxychloroquine, thought [unproven] to provide a measure of safety, somehow interferes with the Covid-porphyrin interaction.