COVID-19 and chronic obstructive pulmonary disease: therapeutic potential of blocking SARS-CoV2 adhesion factors.

The ongoing pandemic of SARS‐CoV2 poses unique challenges to the healthcare community to outsmart the virus and limit both initial infection and subsequent morbidity, especially in patients with pre‐existing chronic obstructive pulmonary disease (COPD) and other pro‐inflammatory chronic disease such as diabetes. Analysis of Chinese data revealed three times higher case fatality among those with COPD. Several potential therapies such as direct anti‐virals and interferons, as well as (hydroxy)‐chloroquine with a less obvious mechanism are under investigation, although early study data suggest that effectiveness is limited.

For many years we have been advocating for a non‐antibiotic approach to common respiratory infections in COPD, such as Haemophilus influenzae and rhinovirus, by utilising what we now know about the general microbial requirement for (blockable) airway epithelial adhesion before clinical infection can occur, for example using available platelet‐activating factor‐receptor (PAFr) blockers. A similar promising therapeutic target with drugs already available could be blockade of host adhesion sites that SARS‐CoV2 employs for epithelial adherence before invasion. These could be used for prophylaxis or just deteriorating respiratory status.

There are now mainly non‐peer‐reviewed reports that show SARS‐CoV2 may bind up to four different epithelial receptors in humans, namely cell‐surface angiotensin‐converting enzyme‐2 (ACE‐2), furin cleavage sites, glucose‐regulated protein‐78 and CD‐147 spike protein. Some of these appear to be upregulated in smokers and especially COPD, as we have found markedly for common respiratory pathogen adhesive proteins, such as PAFr and intercellular adhesion molecule‐1 (ICAM1).

Further reliable verification of these SARS‐CoV2 adhesion sites in smokers, COPD and in others with high‐risk conditions, could be quickly achieved through access to well phenotyped lung tissues, unfortunately even if obtained at post‐mortems. We also need urgent epidemiological data on relative COVID‐19 incidence and outcomes for those already on potential blocking drugs such as ACE antagonists.

Responding to concerns that anti‐ACE drugs may be harmful, a recent Australian/New Zealand consensus statement on managing cardiovascular disease (CVD) and COVID‐19 recommends the continuation of angiotensin‐converting enzyme‐inhibitors (ACE‐I/angiotensin receptor blocker (ARB)) in patients with hypertension, heart failure and CVD, which is in line with the recommendation of American College of Cardiology. Potentially, this could have the dual benefit of managing CVDs and also blocking SARS‐2 viral adhesion to the host respiratory epithelium and indeed in multiple other organs, including intestine, kidney, heart and endothelia, thus mitigating the severity of COVID‐19 in highly susceptible patients with cardiovascular comorbidity.

Several clinical studies assessing the therapeutic potential of ARB are now underway, albeit not in COPD patients (https://clinicaltrials.gov/ct2/results?cond=arb+covid&term=&cntry=&state=&city=&dist=). Thus, especially those COPD patients or smokers who do not respond to the available therapies could be treated with clinically safe anti‐adhesion drugs such as ARB, or TMPRSS2 inhibitor or specific mono‐/polyclonals. It should also be important to collect/analyse epidemiological data for individuals who currently are on ACE‐I/ARB, and compare clinically significant infection rates and outcomes with those not taking such a drug. Any perceivable differences in the prevalence, severity, mortality or SARS‐2 viral titres would help ascertain the role of ACE‐2 in COVID‐19, which may prove helpful for any further waves of this infection, or the next virulent COVID to emerge.