Role of NGAL and Cystatin C in Prediction of Acute Kidney Injury Covid-19 Infection
Condition: Biochemical Markers ,NGAL,Cystatin c, Acute Kidneyinjury, Covid 19
MeSH terms: COVID-19; Acute Kidney Injury
Study type: Observational

Summary: 
      Recent different biomarkers of acute kidney injury (AKI) have been manufactured by
      pharmaceutical industry. Studies proved that Neutrophil gelatinase-associated lipocalin
      (NGAL) and cystatin c are effective predictive biomarkers for early acute kidney injury in
      septic patients and in children after cardiopulmonary bypass. This study hypothesize that
      both cystatin c and Neutrophil gelatinase-associated lipocalin can predict AKI in patients
      with COVID-19 before elevation of serum urea and creatinine which may help early
      interference.
    

Detailed description: 
      Since December 2019, a novel coronavirus called SARSCoV-2 (severe acute respiratory syndrome
      coronavirus 2) has caused an international outbreak of respiratory illness described as
      COVID-19. Among 85 patients with COVID-19 an incidence of acute kidney injury was reported to
      be 23%. The kidney histology from autopsies of six patients showed severe acute tubular
      necrosis with macrophage and lymphocyte infiltration. Another important paper revealed
      prominent acute proximal tubular injury, accumulation of peritubular erythrocyte and
      glomerular fibrin microthrombi after autopsy. However, this kidney injury was not detected by
      routine measures (creatinine and/or BUN) in some patients denoting subclinical kidney injury.
      The pathophysiology of AKI associated with COVID-19 could be due to specific mechanisms such
      as direct cell injury from viral entrance through highly expressed renal ACE2 receptors. Also
      pro-inflammatory cytokines, an imbalanced renin-angotensin-aldosterone system and thrombotic
      events are accused in renal damage. Non-specific mechanisms include hypovolemia, haemodynamic
      changes, right heart failure, high levels of PEEP in mechanically ventilated patients,
      nephrotoxic drugs and nosocomial infections. A significant association between kidney failure
      and death was documented in five studies. Hypoxemia and impairment of gas exchange has been
      identified as elements associated with AKI in patients with acute respiratory distress
      syndrome (ARDS).

      Studies focusing on AKI with COVID-19 are needed urgently in order to identify the mechanism
      of renal affection and to predict the risk of AKI. Pharmaceutical industries with academia
      have made a lot of progress in the field of sensitive and specific preclinical biomarkers of
      kidney injury. Neutrophil gelatinase-associated lipocalin (NGAL) is composed of 178 amino
      acids. this glycoprotein is reabsorbed in the proximal tubules after its filtration through
      the glomeruli.

      In a mouse model of renal ischemia, NGAL gene was rapidly expressed and upregulated within 3
      hours of injury. The NGAL mRNA level increased more than 1000-fold 24-48 hours after injury.
      Thus, NGAL can be a useful tool to diagnose infection mediated AKI. Nonglycosylated Cystatin
      C is a protein produced by nucleated cells at constant rate. It is easily filtered through
      the glomeruli due to its positive charge at physiological pH and its low molecular weight.
      Then, it is reabsorbed and completely catabolized in the proximal tubules. Use of serum
      cystatin C as a marker of glomerular filtration rate (GFR) is well documented, and some
      authors have suggested that it may be more accurate than serum creatinine for this purpose.
      Complete evaluation of the clinical and laboratory picture of COVID-19 associated AKI is
      crucial to design preventive strategies and to suggest targeted interventions
    

Intervention name(s): serum NGAL and cystatin c
Intervention type(s): Diagnostic Test
Intervention description(s): measuring serum NGAL and cystatin c on admission and after 48 hours in critically ill patients with covid 19 then compare results to serum creatinine and signs of acute kidney injury
Intervention MeSH terms: Cystatins
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        adult patients from 18-85 diagnosed as covid 19 infection by nasaopharyngeal swap
      
Biospecimen description: 
      serum refrigerated and divideded into 3 allicots for measurment of NGAL,cystatin c and
      creatinine