Analyzing the Interplay between COVID-19 Viral Load, Inflammatory Markers, and Lymphocyte Subpopulations on the Development of Long COVID

Abstract:

The global impact of the SARS-CoV-2 infection has been substantial, affecting millions of people. Long COVID, characterized by persistent or recurrent symptoms after acute infection, has been reported in over 40% of patients. Risk factors include age and female gender, and various mechanisms, including chronic inflammation and viral persistence, have been implicated in long COVID’s pathogenesis. However, there are scarce studies in which multiple inflammatory markers and viral load are analyzed simultaneously in acute infection to determine how they predict for long COVID at long-term follow-up. This study explores the association between long COVID and inflammatory markers, viral load, and lymphocyte subpopulation during acute infection in hospitalized patients to better understand the risk factors of this disease.
This longitudinal retrospective study was conducted in patients hospitalized with COVID-19 in northern Mexico. Inflammatory parameters, viral load, and lymphocyte subpopulation during the acute infection phase were analyzed, and long COVID symptoms were followed up depending on severity and persistence (weekly or monthly) and assessed 1.5 years after the acute infection.
This study analyzed 79 patients, among them, 41.8% presented long COVID symptoms, with fatigue being the most common (45.5%). Patients with long COVID had higher lymphocyte levels during hospitalization, and NK cell subpopulation levels were also associated with long COVID. ICU admission during acute COVID-19 was also linked to the development of long COVID symptoms.
Source: Rivera-Cavazos A, Luviano-García JA, Garza-Silva A, Morales-Rodríguez DP, Kuri-Ayache M, Sanz-Sánchez MÁ, Santos-Macías JE, Romero-Ibarguengoitia ME, González-Cantú A. Analyzing the Interplay between COVID-19 Viral Load, Inflammatory Markers, and Lymphocyte Subpopulations on the Development of Long COVID. Microorganisms. 2023; 11(9):2241. https://doi.org/10.3390/microorganisms11092241 https://www.mdpi.com/2076-2607/11/9/2241 (Full text)

Post-COVID symptoms are associated with endotypes reflecting poor inflammatory and hemostatic modulation

Abstract:

Introduction: Persistent symptoms after COVID-19 infection (“long COVID”) negatively affects almost half of COVID-19 survivors. Despite its prevalence, its pathophysiology is poorly understood, with multiple host systems likely affected. Here, we followed patients from hospital to discharge and used a systems-biology approach to identify mechanisms of long COVID.

Methods: RNA-seq was performed on whole blood collected early in hospital and 4-12 weeks after discharge from 24 adult COVID-19 patients (10 reported post-COVID symptoms after discharge). Differential gene expression analysis, pathway enrichment, and machine learning methods were used to identify underlying mechanisms for post-COVID symptom development.

Results: Compared to patients with post-COVID symptoms, patients without post-COVID symptoms had larger temporal gene expression changes associated with downregulation of inflammatory and coagulation genes over time. Patients could also be separated into three patient endotypes with differing mechanistic trajectories, which was validated in another published patient cohort. The “Resolved” endotype (lowest rate of post-COVID symptoms) had robust inflammatory and hemostatic responses in hospital that resolved after discharge. Conversely, the inflammatory/hemostatic responses of “Suppressive” and “Unresolved” endotypes (higher rates of patients with post-COVID symptoms) were persistently dampened and activated, respectively. These endotypes were accurately defined by specific blood gene expression signatures (6-7 genes) for potential clinical stratification.

Discussion: This study allowed analysis of long COVID whole blood transcriptomics trajectories while accounting for the issue of patient heterogeneity. Two of the three identified and externally validated endotypes (“Unresolved” and “Suppressive”) were associated with higher rates of post-COVID symptoms and either persistently activated or suppressed inflammation and coagulation processes. Gene biomarkers in blood could potentially be used clinically to stratify patients into different endotypes, paving the way for personalized long COVID treatment.

Source: An AY, Baghela A, Zhang PGY, Blimkie TM, Gauthier J, Kaufmann DE, Acton E, Lee AHY, Levesque RC, Hancock REW. Post-COVID symptoms are associated with endotypes reflecting poor inflammatory and hemostatic modulation. Front Immunol. 2023 Aug 23;14:1243689. doi: 10.3389/fimmu.2023.1243689. PMID: 37680625; PMCID: PMC10482103. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10482103/ (Full text)

SARS-CoV-2-Specific Immune Responses in Patients With Postviral Syndrome After Suspected COVID-19

Abstract:

Background and objectives: Millions of Americans were exposed to SARS-CoV-2 early in the pandemic but could not get diagnosed with COVID-19 due to testing limitations. Many have developed a postviral syndrome (PVS) including neurologic manifestations similar to those with postacute sequelae of SARS-CoV-2 infection (Neuro-PASC). Owing to those circumstances, proof of SARS-CoV-2 infection was not required for evaluation at Northwestern Medicine’s Neuro COVID-19 clinic. We sought to investigate clinical and immunologic findings suggestive of SARS-CoV-2 exposure in patients with PVS.

Methods: We measured SARS-CoV-2-specific humoral and cell-mediated immune responses against Nucleocapsid and Spike proteins in 29 patients with PVS after suspected COVID-19, 32 confirmed age-matched/sex-matched Neuro-PASC (NP) patients, and 18 unexposed healthy controls. Neurologic symptoms and signs, comorbidities, quality of life, and cognitive testing data collected during clinic visits were studied retrospectively.

Results: Of 29 patients with PVS, 12 (41%) had detectable humoral or cellular immune responses consistent with prior exposure to SARS-CoV-2. Of 12 PVS responders (PVS+), 75% harbored anti-Nucleocapsid and 50% harbored anti-Spike responses. Patients with PVS+ had similar neurologic symptoms as patients with NP, but clinic evaluation occurred 5.3 months later from the time of symptom onset (10.7 vs 5.4 months; p = 0.0006). Patients with PVS+ and NP had similar subjective impairments in quality of life measures including cognitive function and fatigue. Patients with PVS+ had similar results in objective cognitive measures of processing speed, attention, and executive function and better results in working memory than patients with NP.

Discussion: Antibody and T-cell assays showed evidence of prior SARS-CoV-2 exposure in approximately 40% of the PVS group. Three-quarters of patients with PVS+ had detectable anti-Nucleocapsid and one-half anti-Spike responses, highlighting the importance of multitargeted COVID-19 immunologic evaluation and the limitations of commercially available diagnostic tests. Despite their persistent symptoms, lack of COVID-19 diagnosis likely delayed clinical care in patients with PVS. Our data suggest that millions of Americans presenting with PVS resembling Neuro-PASC were indeed exposed to SARS-CoV-2 at the beginning of the pandemic, and they deserve the same access to care and inclusion in research studies as patients with NP with confirmed COVID-19 diagnosis.

Source:Orban ZS, Visvabharathy L, Perez Giraldo GS, Jimenez M, Koralnik IJ. SARS-CoV-2-Specific Immune Responses in Patients With Postviral Syndrome After Suspected COVID-19. Neurol Neuroimmunol Neuroinflamm. 2023 Aug 23;10(6):e200159. doi: 10.1212/NXI.0000000000200159. PMID: 37612134; PMCID: PMC10448973. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10448973/ (Full text)

Prevalence of Symptoms ≤12 Months After Acute Illness, by COVID-19 Testing Status Among Adults — United States, December 2020–March 2023

Summary:

What is already known about this topic? Post-COVID conditions, or long COVID, can persist for months or years after an acute COVID-19 illness and can include emergence of new symptoms or the occurrence of symptoms that come and go.

What is added by this report? In a multicenter study of adults with a COVID-like illness, symptom prevalence decreased over time after the acute illness. Approximately 16% of adults with COVID-like symptoms reported persistent symptoms 12 months after a positive or negative SARS-CoV-2 test result. At 3, 6, 9, and 12 months after testing, some symptomatic persons had ongoing symptoms, and others had emerging symptoms not reported during the previous period.

What are the implications for public health practice? Health care providers should be aware that symptoms can persist, emerge, reemerge, or resolve after COVID-like illness and are not unique to COVID-19 or to post-COVID conditions.

Abstract:

To further the understanding of post-COVID conditions, and provide a more nuanced description of symptom progression, resolution, emergence, and reemergence after SARS-CoV-2 infection or COVID-like illness, analysts examined data from the Innovative Support for Patients with SARS-CoV-2 Infections Registry (INSPIRE), a prospective multicenter cohort study. This report includes analysis of data on self-reported symptoms collected from 1,296 adults with COVID-like illness who were tested for SARS-CoV-2 using a Food and Drug Administration–approved polymerase chain reaction or antigen test at the time of enrollment and reported symptoms at 3-month intervals for 12 months.

Prevalence of any symptom decreased substantially between baseline and the 3-month follow-up, from 98.4% to 48.2% for persons who received a positive SARS-CoV-2 test results (COVID test–positive participants) and from 88.2% to 36.6% for persons who received negative SARS-CoV-2 test results (COVID test–negative participants).

Persistent symptoms decreased through 12 months; no difference between the groups was observed at 12 months (prevalence among COVID test–positive and COVID test–negative participants = 18.3% and 16.1%, respectively; p>0.05).

Both groups reported symptoms that emerged or reemerged at 6, 9, and 12 months. Thus, these symptoms are not unique to COVID-19 or to post-COVID conditions. Awareness that symptoms might persist for up to 12 months, and that many symptoms might emerge or reemerge in the year after COVID-like illness, can assist health care providers in understanding the clinical signs and symptoms associated with post-COVID–like conditions.

Source: Montoy JC, Ford J, Yu H, et al. Prevalence of Symptoms ≤12 Months After Acute Illness, by COVID-19 Testing Status Among Adults — United States, December 2020–March 2023. MMWR Morb Mortal Wkly Rep 2023;72:859–865. DOI: http://dx.doi.org/10.15585/mmwr.mm7232a2 (Full text)

The effects of COVID-19 on cognitive performance in a community-based cohort: a COVID symptom study biobank prospective cohort study

Abstract:

Background: Cognitive impairment has been reported after many types of infection, including SARS-CoV-2. Whether deficits following SARS-CoV-2 improve over time is unclear. Studies to date have focused on hospitalised individuals with up to a year follow-up. The presence, magnitude, persistence and correlations of effects in community-based cases remain relatively unexplored.

Methods: Cognitive performance (working memory, attention, reasoning, motor control) was assessed in a prospective cohort study of participants from the United Kingdom COVID Symptom Study Biobank between July 12, 2021 and August 27, 2021 (Round 1), and between April 28, 2022 and June 21, 2022 (Round 2). Participants, recruited from the COVID Symptom Study smartphone app, comprised individuals with and without SARS-CoV-2 infection and varying symptom duration. Effects of COVID-19 exposures on cognitive accuracy and reaction time scores were estimated using multivariable ordinary least squares linear regression models weighted for inverse probability of participation, adjusting for potential confounders and mediators. The role of ongoing symptoms after COVID-19 infection was examined stratifying for self-perceived recovery. Longitudinal analysis assessed change in cognitive performance between rounds.

Findings: 3335 individuals completed Round 1, of whom 1768 also completed Round 2. At Round 1, individuals with previous positive SARS-CoV-2 tests had lower cognitive accuracy (N = 1737, β = -0.14 standard deviations, SDs, 95% confidence intervals, CI: -0.21, -0.07) than negative controls. Deficits were largest for positive individuals with ≥12 weeks of symptoms (N = 495, β = -0.22 SDs, 95% CI: -0.35, -0.09). Effects were comparable to hospital presentation during illness (N = 281, β = -0.31 SDs, 95% CI: -0.44, -0.18), and 10 years age difference (60-70 years vs. 50-60 years, β = -0.21 SDs, 95% CI: -0.30, -0.13) in the whole study population. Stratification by self-reported recovery revealed that deficits were only detectable in SARS-CoV-2 positive individuals who did not feel recovered from COVID-19, whereas individuals who reported full recovery showed no deficits. Longitudinal analysis showed no evidence of cognitive change over time, suggesting that cognitive deficits for affected individuals persisted at almost 2 years since initial infection.

Interpretation: Cognitive deficits following SARS-CoV-2 infection were detectable nearly two years post infection, and largest for individuals with longer symptom durations, ongoing symptoms, and/or more severe infection. However, no such deficits were detected in individuals who reported full recovery from COVID-19. Further work is needed to monitor and develop understanding of recovery mechanisms for those with ongoing symptoms.

Source: Cheetham NJ, Penfold R, Giunchiglia V, Bowyer V, Sudre CH, Canas LS, Deng J, Murray B, Kerfoot E, Antonelli M, Rjoob K, Molteni E, Österdahl MF, Harvey NR, Trender WR, Malim MH, Doores KJ, Hellyer PJ, Modat M, Hammers A, Ourselin S, Duncan EL, Hampshire A, Steves CJ. The effects of COVID-19 on cognitive performance in a community-based cohort: a COVID symptom study biobank prospective cohort study. EClinicalMedicine. 2023 Jul 21;62:102086. doi: 10.1016/j.eclinm.2023.102086. PMID: 37654669; PMCID: PMC10466229. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10466229/ (Full text)

Acute blood biomarker profiles predict cognitive deficits 6 and 12 months after COVID-19 hospitalization

Abstract:

Post-COVID cognitive deficits, including ‘brain fog’, are clinically complex, with both objective and subjective components. They are common and debilitating, and can affect the ability to work, yet their biological underpinnings remain unknown.

In this prospective cohort study of 1,837 adults hospitalized with COVID-19, we identified two distinct biomarker profiles measured during the acute admission, which predict cognitive outcomes 6 and 12 months after COVID-19.

A first profile links elevated fibrinogen relative to C-reactive protein with both objective and subjective cognitive deficits. A second profile links elevated D-dimer relative to C-reactive protein with subjective cognitive deficits and occupational impact. This second profile was mediated by fatigue and shortness of breath. Neither profile was significantly mediated by depression or anxiety.

Results were robust across secondary analyses. They were replicated, and their specificity to COVID-19 tested, in a large-scale electronic health records dataset. These findings provide insights into the heterogeneous biology of post-COVID cognitive deficits.

Source: Taquet, M., Skorniewska, Z., Hampshire, A. et al. Acute blood biomarker profiles predict cognitive deficits 6 and 12 months after COVID-19 hospitalization. Nat Med (2023). https://doi.org/10.1038/s41591-023-02525-y https://www.nature.com/articles/s41591-023-02525-y (Full text)

Treatment of Brain Fog of Long COVID Syndrome: A Hypothesis

Abstract:

The emergence of the SARS-CoV-2 (COVID-19) virus has exacted a significant toll on the global population in terms of fatalities, health consequences, and economics. As of February 2023, there have been almost 800 million confirmed cases of the disorder reported to the WHO [1], although the actual case-positive rate is estimated to be much higher.

While many cases recover, the mortality rate associated with the illness is about 1% (based on the WHO data). Most patients experience the illness as a mild to moderate disorder and recover without significant sequelae. However, as the COVID-19 pandemic has continued, there has emerged a significant group of COVID-19 survivors who experience persistent symptoms beyond the acute course of the illness.

As many as one in eight patients report persistent symptoms 90 to 150 days after the initial infection [2]. These so-called Long COVID or post-COVID syndrome patients are mostly drawn from those who were hospitalised for the disorder, but both non-hospitalised and vaccinated subjects may also experience the syndrome [3]. While an agreed definition of Long COVID is yet to be settled, a multiplicity of symptoms affecting most major organ systems has been reported in patients.

Common Long COVID symptoms include fatigue, dyspnoea, headaches, myalgia, anosmia, dysgeusia, cognitive symptoms, and mental disorders such as depression and anxiety [4]. It is estimated that approximately a third of patients with Long COVID exhibit either fatigue, cognitive impairment, or both up to 12 weeks after a confirmed diagnosis of COVID-19 [5].

Source: Norman TR. Treatment of Brain Fog of Long COVID Syndrome: A Hypothesis. Psychiatry International. 2023; 4(3):242-245. https://doi.org/10.3390/psychiatryint4030024 https://www.mdpi.com/2673-5318/4/3/24 (Full text)

Prevalence of Post-Acute COVID-19 Sequalae and Average Time to Diagnosis Among Persons Living With HIV

Abstract:

Aims: The aims of this meta-analysis were to assess: the prevalence of Post-Acute COVID-19 sequalae in HIV positive patients; average time of diagnosis; and meta-regress for possible moderators of PACS.
Methods: A standard search strategy was used in PubMed, and then later modified according to each specific database to get the best relevant results. These included Medline indexed journals; PubMed Central; NCBI Bookshelf and publishers’ Web sites in line with the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Search terms included “long COVID-19 or post-acute COVID-19 syndrome/sequalae”, “persons living with HIV or HIV. The criteria for inclusion were published clinical articles reporting HIV in association with long COVID-19, further, the average time to an event of post-acute COVID-19 sequelae among primary infected patients with COVID-19. Random-effects model was used. Rank Correlation and Egger’s tests were used to ascertain publication bias. Sub-group, sensitivity and meta-regression analysis were conducted. A 95% confidence intervals were presented and a p-value < 0.05 was considered statistically significant. Review Manager 5.4 and comprehensive meta-analysis version 4 (CMA V4) were used for the analysis. The review/trial was PROSPERO registered (CRD42022328509).
Results: A total of 43 studies reported post-acute COVID-19 syndrome. Of those, five reported post-acute COVID-19 sequalae in PLHIV. Prevalence of post-acute COVID-19 sequalae was 43.1% (95% CI 20.5% to 68.9%) in persons living with HIV (PLWH). The average time to PACS diagnosis was 4 months at 64% [0.64 (95% CI 0.230, 0.913) (P < 0.0000), I2= 93%] and at one year to PACS diagnosis was at 70 %, however with non-significant correlation (P > 0.05). On comorbidities, asthenia was associated with PACS at 17.6 % [0.176 (95% CI 0.067, 0.385) (P = 0.008), I2= 86%] while fatigue at 82%, however not related with PACS event incidence (P < 0.05). Americas, Asian and European regions showed PACS events rates of 82%, 43% and 19 % respectively (P<0.05) relative to HIV infection.
Conclusion: PACS prevalence in PLWH was 43% occurring at an average time of 4 months at 64% and 70 % at 12 months however non-significant with PACS. Asthenia was significantly associated with PACS at 17.6 % while fatigue at 82%, however not related with PACS event incidence. Americas recorded the highest PACS event rates in PLWH.
Source: Muthuka, J.; Nyamai, E.; Onyango, C.; Oluoch, K.; Nabaweesi, R. Prevalence of Post-Acute COVID-19 Sequalae and Average Time to Diagnosis Among Persons Living With HIV. Preprints 2023, 2023081633. https://doi.org/10.20944/preprints202308.1633.v1 https://www.preprints.org/manuscript/202308.1633/v1 (Full text available as PDF file)

Prevalence, pathogenesis and spectrum of neurological symptoms in COVID-19 and post-COVID-19 syndrome: a narrative review

Summary:

  • Neurological symptoms are not uncommon during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and reflect a broad spectrum of neurological disorders of which clinicians should be aware.
  • The underlying pathogenesis of neurological disease in coronavirus disease 2019 (COVID-19) may be due to four mechanisms of nervous system dysfunction and injury: i) direct viral neurological invasion; ii) immune dysregulation; iii) endothelial dysfunction and coagulopathy; and iv) severe systemic COVID-19 disease.
  • Neurological manifestations of acute COVID-19 include headache, peripheral neuropathies, seizures, encephalitis, Guillain–Barré syndrome, and cerebrovascular disease.
  • Commonly reported long term neurological sequelae of COVID-19 are cognitive dysfunction and dysautonomia, which despite being associated with severe acute disease are also seen in people with mild disease.
  • Assessment of cognitive dysfunction after COVID-19 is confounded by a high prevalence of comorbid fatigue, anxiety, and mood disorders. However, other markers of neuroaxonal breakdown suggest no significant neuronal injury apart from during severe acute COVID-19.
  • The long term impact of COVID-19 on neurological diseases remains uncertain and requires ongoing vigilance.

Source: Wesselingh, R. (2023), Prevalence, pathogenesis and spectrum of neurological symptoms in COVID-19 and post-COVID-19 syndrome: a narrative review. Med J Aust. https://doi.org/10.5694/mja2.52063 https://onlinelibrary.wiley.com/doi/10.5694/mja2.52063 (Full text available as PDF file)

 

Long-term health consequences among individuals with SARS-CoV-2 infection compared to individuals without infection: results of the population-based cohort study CoMoLo Follow-up

Abstract:

Background: Most of the previous studies on health sequelae of COVID-19 are uncontrolled cohorts and include a relatively short follow-up. This population-based multi-center cohort study examined health consequences among individuals about 1 to 1.5 years after SARS-CoV-2 infection compared with non-infected.

Methods: The study population consisted of adults (≥ 18 years) from four municipalities particularly affected by the COVID-19 pandemic in the year 2020 who completed a detailed follow-up questionnaire on health-related topics. Exposure was the SARS-CoV-2 infection status (based on IgG antibodies, PCR test, or physician-diagnosis of COVID-19) at baseline (May to December 2020). Outcomes assessed at follow-up (October 2021 to January 2022; mean: 452 days) included recurrent or persistent health complaints, incident diseases, health-related quality of life (PROMIS-29), subjective health, and subjective memory impairment. Logistic and linear regression models were adjusted for baseline sociodemographic and lifestyle characteristics (age, sex, municipality, education, smoking, body mass index), pre-existing health conditions (chronic disease/health problem, health-related activity limitation, depressive/anxiety disorder), and follow-up time.

Results: Among 4817 participants, 350 had a SARS-CoV-2 infection at baseline and 4467 had no infection at baseline or during follow-up. Those with an infection statistically significantly more often reported 7 out of 18 recurrent or persistent health complaints at follow-up: smell/taste disorders (12.8% vs. 3.4%, OR 4.11), shortness of breath (23.0% vs. 9.5%, 3.46), pain when breathing (4.7% vs. 1.9%, 2.36), fatigue (36.9% vs. 26.1%, 1.76), weakness in legs (12.8% vs. 7.8%, 1.93), myalgia/joint pain (21.9% vs. 15.1%, 1.53) and cough (30.8% vs. 24.8%, 1.34) and 3 out of 6 groups of incident diseases: liver/kidney (2.7% vs. 0.9%, 3.70), lung (3.2% vs. 1.1%, 3.50) and cardiovascular/metabolic (6.5% vs. 4.0%, 1.68) diseases. Those with an infection were significantly more likely to report poor subjective health (19.3% vs. 13.0%, 1.91), memory impairment (25.7% vs. 14.3%, 2.27), and worse mean scores on fatigue and physical function domains of PROMIS-29 than non-infected.

Conclusion: Even after more than one year, individuals with SARS-CoV-2 infection showed an increased risk of various health complaints, functional limitations, and worse subjective well-being, pointing toward profound health consequences of SARS-CoV-2 infection relevant for public health.

Source: Heidemann C, Sarganas G, Du Y, Gaertner B, Poethko-Müller C, Cohrdes C, Schmidt S, Schlaud M, Scheidt-Nave C. Long-term health consequences among individuals with SARS-CoV-2 infection compared to individuals without infection: results of the population-based cohort study CoMoLo Follow-up. BMC Public Health. 2023 Aug 21;23(1):1587. doi: 10.1186/s12889-023-16524-8. PMID: 37605232; PMCID: PMC10440884. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10440884/ (Full text)