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.
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
Diagnostic Test: serum NGAL and cystatin c
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
Inclusion Criteria:
- person with the one of the following symptoms: fever and respiratory symptoms with
radiological findings of pneumonia compatible with COVID-19
1. Respiratory distress (≥ 30 breaths/ min);
2. Oxygen saturation ≤ 93% at rest;
3. Arterial partial pressure of oxygen (PaO2)/ fraction of inspired oxygen (FIO2) ≤
300.
4. Cases with chest imaging that shows obvious lesion progression within 24-48 hours
> 50%.
5. Respiratory failure and requiring mechanical ventilation;
6. Shock;
7. other organ failure that requires ICU care.
Exclusion Criteria:
- patients classified as mild corona virsus disease, patients with end-stage renal
disease (ESRD) or on chronic regular dialysis, presence of AKI and anuria at the time
of ICU admission, history of chronic kidney disease, severe urinary tract infection,
kidney malignancy, and renal transplantation.
Ainshams hospitals
Cairo, Egypt
Sanaa Wasfy
New Cairo, Egypt
sanaa wasfy, Principal Investigator
lecturer