Testing for COVID-19
The Quality In Diagnostics Is Our Passion!
Three Type of Tests are Available for COVID-19:
The Covid-19 pandemic has been engulfing the entire world that most people have never imagined, yet alone witnessed. As the number of SARS-CoV-2 infected individuals and deaths continue to increase, it has overloaded healthcare systems even in advanced countries. This pandemic combines an unfortunate double jeopardy: rapid loss of human lives that has resulted into general panic in the gripping populations. Novel coronavirus shares 80% of its genome with SARS-CoV hence, given name of SARS-CoV-2 by WHO.
Real Time PCR assay can use SARS-CoV genomic RNA as a template to convert it into cDNA and quantify it while amplification. Four conserved regions have been identified for specific amplification of SARS-COV-2 genes i.e. E gene, ORF1ab/RdRp gene, S gene and N gene. Multiplex RT-PCR is being used to detect COVID-19 for simultaneous amplification of the two to three genes to avoid extensive labor, save time to make the test cost effective. WHO recommended procedures are being followed in the laboratory for the precise and accurate detection of SARS-COV-2.
Surgimed lab has started the state of art molecular diagnostic laboratory for Real Time PCR based COVID-19 testing. We are using CE certified kits. Foreign qualified and well trained molecular biologists having PhDs are overseeing the quality testing of COVID-19. Surgimed Lab. is providing walk in Sampling as well as Home Sampling services. Patient through online reporting system can get reports well in time using our website. It’s part of Surgimed Hospital, 1-Zafar Ali Road Lahore
What Samples are taken for COVID-19 Testing:
- Blood Samples
“It is not SARS-CoV-2 that is killing the patients it’s their own immune system”
The pathogenic coronaviruses (severe acute respiratory syndrome coronavirus SARS-CoV and SARSCoV-2 bind to their target cells by the interaction of its spike (S) protein with angiotensin-converting enzyme 2 (ACE-2) receptor. The older age, high number of comorbidities, and abnormal levels of inflammation related markers have shown association with the severity of the disease in critically ill patients. The most common comorbidities of COVID-19 patients with poor prognosis were diabetes mellitus (20%, other study reported 30%) hypertension (15%) and cardiovascular diseases (15%)2.Due to endocytosis of viral entry receptor (ACE2 receptor) the expression levels of ACE2 are decreased in old and comorbid patients that facilitates a more robust viral infection, which consequently results in a Cytokine Storm (Hyperactivity of immune cells). The host’s genetic predisposition (e.g. ACE2 polymorphisms) might play a significant role for an increased risk of SARS-CoV-2 infection especially in the young severe COVID-19 cases.
There is no test available locally to detect Cytokine Storm which is responsible for the mortality among COVID-19 patients. Reducing the rate of new infections and preventing transmission are the primary goals of health care systems across the globe; however, the critical illness and death caused by COVID-19 is the core of public anxiety. It’s the in-house optimized assay to test the real time levels of several inflammatory biomarkers for example Interlukin-6, using real time PCR. This test detects Cytokines Storm (Hyper immunity) in COVID-19 patients and quantifies the levels of inflammation at earlier time points. The levels of inflammatory biomarkers determine the severity of the disease. Based on the inflammation levels of COVID-19 patients, additional therapies along with the background therapy may be helpful for the better management of the disease. This test will help to isolate and manage the COVID-19 patient who may develop the disease severity at later stage.
More details of Cytokines Storm Test
The outbreak of disease caused by a novel coronavirus, originally named “2019 novel coronavirus (2019-nCoV)” and then later officially named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been declared a pandemic by the WHO. The SARS-CoV-2 has a strong transmission capacity when compared to the 2003 SARS outbreak. The Chinese Centers for Disease Control and Prevention recently classified symptoms of the Coronavirus disease (COVID-19) in patients. Patients with shortness of breath and pneumonia are considered “Severe” (14% of the confirmed cases) and patients who develop respiratory failure, septic shock and multiple organ failure are termed “critical” or “critically ill” patients (5%). These critically ill patients are at a greater risk of death, and 2.3% of confirmed cases did result in death1. The overall fatality rate of, healthy people, is less than 1%, this contrasts with the fatality rate in patients with comorbidities1,2 i.e. cardiovascular, diabetes and chronic respiratory disease and hypertension are 10.5, 7.3, 6.3, and 6% respectively. Reducing the rate of new infections and preventing transmission are the primary goals of health care systems across the globe; however, the critical illness and death caused by COVID-19 is the core of public anxiety.
The pathogenic coronaviruses (severe acute respiratory syndrome coronavirus SARS-CoV and SARSCoV-2 bind to their target cells by the interaction of its spike (S) protein with angiotensin-converting enzyme 2 (ACE-2) receptor. Human epithelial cells of the lung, intestine, kidney, and blood vessels express this receptor. A host transmembrane serine protease (TMPRSS2) promotes entry of SARS-CoV-2. TMPRSS2 cleaves S generating a fusion mediating subunit S2, which facilitates virus–cell membrane fusion and consequently the infection3. Another protease, cathepsin (B/L) has been also proposed to facilitate the entry of SARS-CoV-2 in the cell through ACE2 receptor. However the mechanism for the interaction of cathepsin B/L with ACE2 receptor for viral entry needs further investigation. The older age, high number of comorbidities, and abnormal levels of inflammation related markers have shown association with the severity of the disease in critically ill patients. The most common comorbidities of COVID-19 patients with poor prognosis were diabetes mellitus (20%, other study reported 30%) hypertension (15%) and cardiovascular diseases (15%)2. Diabetes and hypertension therapy with ACE inhibitors and angiotensin II type-I receptor blockers (ARBs) increases the expression of ACE-2. The higher expression levels of ACE2 and TMPRSS2 in old and comorbid patients may facilitate a more robust viral infection, which consequently results in a hyperactivity of immune cells 4. The host’s genetic predisposition (e.g. ACE2/ TMPRSS2 polymorphisms) might play a significant role for an increased risk of SARS-CoV-2 infection4 especially in the young severe COVID-19 cases.
The most common complications of the COVID-19 severity were acute respiratory distress syndrome (>60%), arrhythmia (>44%), septic shock (>30%) and multi organ failure in the patients, who received ICU care5. SARS- CoV-2 infection activates innate and adaptive immune responses. The lymphopenia with critically reduced numbers of CD4+ T cells, CD8+ T cells, B cells and natural killer (NK) cells and reduced percentage of monocytes, eosinophils and basophils are the common features of severe COVID-19. An increase in neutrophil count and in the neutrophil-to-lymphocyte ratio is another indicator of higher disease severity and poor clinical outcomes of COVID-19 patients2. The recent report have shown an improvement in the clinical outcomes of severe COVID-19 by convalescent plasma transfusion, which increased lymphocyte counts and neutralized the viremia6. Hence, the hyperactive inflammatory innate responses and impaired adaptive immune responses may be responsible for tissue damage at both local and systemic levels.
Recent observational study have reported that the higher expression levels of biomarkers for inflammation and disturbed coagulation mechanism such as d-dimer, high-sensitivity cardiac troponin I, serum ferritin, lactate dehydrogenase, IL-6 and interleukin-2 receptor (IL-2R) are the risk factors associated with death in Chinese hospitalized patients. Moreover, the expression levels of inflammatory markers in the critical patients were positively correlated with illness deterioration7,8 table 1. For instance, the elevated levels of IL-6 have been associated with the high flow oxygen inhalation, mechanical ventilation, administration of glucocorticoids and human immunoglobulin in ICU patients8. In another cohort, the critically ill patients (ICU patients) have shown high concentrations of cytokines such as GCSF, IP10, MCP1, MIP1A, and TNFα in their plasma compared with non-ICU, which points to an acute inflammatory response2. More importantly, these reports also suggested that elevated levels of lactate dehydrogenase (LDH), interleukin (IL) 6, C-reactive protein (CRP) and IL-2R of critically ill COVID-19 patients are also responsible for CS exacerbated pathological damage in hosts. Mechanistically, activated immune cells respond by secreting several cytokine molecules that cause inflammation, this phenomenon leads to pulmonary inflammation. Pulmonary inflammation causes severe damage to the lungs; assisted breathing by using ventilators is not always successful in preventing demise of such patients. Preponderance of such cytokines can lead to acute respiratory distress syndrome (ARDS), septic shock, acute cardiac injury and multi-organ dysfunction.
Early reports emanating from China indicate favorable outcomes in a series of severely ill COVID-19 patients treated with a regimen that included therapy with siltuximab and tocilizumab, also known as Actemra (monoclonal antibodies), which leads to blockade of the IL-6 receptor 8. Moreover, US Food and Drug Administration (FDA) has recently approved the phase 3 trial of Actemra in severely ill COVID-19 patients. The high-doses intravenous immunoglobulin and low-molecular-weight heparin anticoagulant therapy have been recommended to critically ill COVID-19 patients when the d-dimer value is 4 times higher than the normal upper limit 9. Moreover the administration of Chloroquine or Hydroxychloroquine did not only block the invasion and replication of coronavirus, but also attenuated the possibility of CS by suppressing T cell activation 10. The significant increase in the expression levels of CRP, ferritin, IL-6 and LDH have been closely related to COVID-19 severity and more intensive and prolonged treatment. The promising therapy options for such cases include human immunoglobulin, stronger antibiotics and high flow oxygen therapy or mechanical ventilation8.
The severity of COVID-19 burdens the critical care resources in hospitals, especially the hospitals that are deficient in staff and/or relevant equipment and supplies. Therefore, developing a cost-effective molecular markers test to screen out the patients who are at a higher risk due to their age, comorbidity and/or genetics would be helpful for precise and effective treatment. An early quantification of virus entry markers of such as ACE2, TMPRSS2 could be used as an effective prognostic tool. The inflammatory markers such as CRP, IL-6, IL-2R, GCSF, IP10, MCP1, MIP1A, TNFα, and the coagulation parameters Ferritin, D-Dimer, high-sensitivity cardiac troponin I, and LDH have shown significant differential expression in critically ill COVID-19 patients at day 4 after the viral infection. The patients usually develops CS in first few days of infection which may be detected, and patient may be treated before the critical illness and multiple organs damage but if it goes untreated, it may leads to disease severity, consequently, acute respiratory distress syndrome (ARDS), septic shock, acute cardiac injury and multi-organ dysfunction. This opinion proposes that the CS-driven disease severity may be detected early in time in COVID-19 patients by quantifying the expression levels of these inflammatory markers and coagulation parameters. The real time quantification of the markers by polymerase chain reaction (PCR) may isolate COVID-19 patients at early time points who are heading toward CS-driven severe disease. The treatment regimen may be divided in to two phases i.e. immune boosting during the initial protective phase or immune suppressing during cytokine storm driven damaging phase by real time quantification of expression levels for these markers. The monitoring of the molecular markers will not only reduce the need of mechanical ventilation by timely detection of levels of host’s response to infection but will be also very helpful for the clinicians to formulate a timely therapeutic strategy for COVID-19 severe patients that could save several lives.
Conflicts of Interest and Financial Disclosures:
All authors declare no competing and financial interests.
Table 1. The correlation of the disease severity with the levels of inflammatory and coagulation markers in COVID-19 patients
Ferritin (μg /L)
- Wu Z, McGoogan JM. Characteristics of and Important Lessons From the Coronavirus Disease 2019 (COVID-19) Outbreak in China: Summary of a Report of 72314 Cases From the Chinese Center for Disease Control and Prevention. Jama. 2020.
- Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet. 2020;395(10223):497-506.
- Ou X, Liu Y, Lei X, et al. Characterization of spike glycoprotein of SARS-CoV-2 on virus entry and its immune cross-reactivity with SARS-CoV. Nature communications. 2020;11(1):1620.
- Fang L, Karakiulakis G, Roth M. Are patients with hypertension and diabetes mellitus at increased risk for COVID-19 infection? The Lancet Respiratory medicine. 2020.
- Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. Jama. 2020.
- Duan K, Liu B, Li C, et al. Effectiveness of convalescent plasma therapy in severe COVID-19 patients. Proceedings of the National Academy of Sciences of the United States of America. 2020.
- Chen L, Liu HG, Liu W, et al. [Analysis of clinical features of 29 patients with 2019 novel coronavirus pneumonia]. Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases. 2020;43(0):E005.
- Liu T, Zhang J, Yang Y, et al. The potential role of IL-6 in monitoring severe case of coronavirus disease 2019. medRxiv. 2020:2020.2003.2001.20029769.
- Lin L, Lu L, Cao W, Li T. Hypothesis for potential pathogenesis of SARS-CoV-2 infection–a review of immune changes in patients with viral pneumonia. Emerging microbes & infections. 2020:1-14.
- Zhou D, Dai SM, Tong Q. COVID-19: a recommendation to examine the effect of hydroxychloroquine in preventing infection and progression. The Journal of antimicrobial chemotherapy. 2020.
An antibody test does not provide information for current coronavirus infection however it is very informative test that indicates the past infection. The immune response to coronavirus infection is little delayed in comparison to flu virus which is 5-7 days as we all know. However in case of coronavirus, The immune response can take longer time as IgM antibody start appearing at day 9 and IgG appears at day 11. The levels of both the antibodies reach to peak in about 2 week time after infection.
Having antibodies to the virus that causes COVID-19 might provide protection from getting infected with the virus again. If it does, we do not know how much protection the antibodies might provide or how long this protection might last.
Infection results in an immune response leading to the production of antibodies as well as the involvement of T-cells. A vast majority of COVID-19 patients develop an immune response against SARS-CoV-2 with the activation of T-cells to the spike-protein of the virus. By recognizing the spike-protein specifically the receptor-binding domain – which is the most effective site for neutralizing antibodies – a robust immune response can be mounted and may remain protective for future infections.