Spinal Cord Injury Patients May Have Milder Covid-19 Symptoms

A research group in Madrid, Spain has published preliminary evidence in the Journal of Personalized Medicine ^[1] that patients with spinal cord injuries may experience milder COVID-19 symptoms than the general population.

Spinal cord injury (SCI) is a serious condition which can result in multiple physiological complications. As such, it was deemed likely that patients with these injuries might be particularly vulnerable to COVID-19 complications and poor outcomes. Thankfully, the opposite seems to be true—thus far evidence supports the observation that SCI patients display milder COVID-19 symptoms than the general population. Researchers are trying to determine why this would be the case, and whether the answer can be used to help more COVID-19 patients have good outcomes.

The authors worked with a relatively small cohort of SCI patients at the National Hospital for Paraplegics in Toledo Spain. After obtaining patient consent, they used a proteomics-based approach to analyze plasma samples from SCI patients either with or without COVID-19.  

The first phase of the experimental strategy consisted of a differential protein analysis done using mass spectrometry. For this analysis, the authors made use of Pall Nanosep® 10k Omega™ centrifugal filters to remove excess labelling agent from the protein preparation.   

Pall Nanosep 10k Omega filters are designed to rapidly concentrate 50-500 μL sample volumes with > 90 % recovery. They are available with low protein-binding Omega and Bio-Inert^® filters in a range of MWCO which are color coded for easy identification.  

For larger sample volumes, Pall also make additional centrifugal filters: the Microsep™ for 0.5 to 5 mL sample volume, the Macrosep® for 5 to 20 mL sample volume, and the Jumbosep™ for 20 to 60 mL sample volume.   

Following tryptic digest, labelled peptides were identified and quantified using mass spectrometry. The results showed that SCI patients infected by COVID-19 had differential expression of 33 proteins, with 20 being upregulated, and 13 downregulated. 12 of these proteins fell into three broad functional categories: platelet aggregation, coagulation, and fibrinolysis. 

In the second phase of the study, the authors used Western blot analysis to validate their results. Western blot analysis validated that haptoglobin, hemoglobin and other related proteins were clearly more abundant in COVID-19 infected SCI patients, while fibrinogen and other proteins involved in clot formation were downregulated in the SCI-COVID-19 patients.

While the sample size in this study is too small to form any overreaching conclusion, it has been established that severe COVID-19 disease is marked by elevated plasma viscosity, and an increased tendency toward blood clot formation, both of which play an important role in the pathogenesis of the SARS-CoV-2 virus. The authors noted that both physiological characteristics and SCI-related treatment regimens are likely contributing to the milder disease seen in SCI-COVID-19 patients. Further research along these lines is certainly warranted.

Pall’s Nanosep filters can easily be integrated into your research workflow. Use Pall’s Nanosep and Microsep concentration selection guide to concentrate your sample to the exact concentration of your choice. With > 90 % recovery, you have nothing to lose.

Reference:

1. Calvo E. et al. Why Does COVID-19 Affect Patients with Spinal Cord Injury Milder? A Case-Control Study: Results from Two Observational Cohorts. J Pers Med. 10(4): 182. Dec 2020.