The Science of COVID-19: COVID-19 and Acute Kidney Injury

Dr. Haimchand Barran
MMSc Internal Medicine/Infectious Diseases
Fellowship — Nephrology
Nephrology Department — GPHC
COVID-19 predominantly affects individuals between 30 and 79 years of age, with 81 percent of cases being classified as mild.
Despite the majority of the general population displaying symptoms similar to the common cold, COVID-19 has also induced alveolar (lungs tissue) damage, resulting in progressive respiratory failure with fatalities noted in 6.4 percent of cases.
Patients with COVID-19 have displayed kidney damage through acute kidney injury (AKI), mild proteinuria (protein in the urine), hematuria (blood in the urine), or slight elevation in creatinine (blood marker testing for kidney function), possibly as consequence of kidney tropism of the virus and multiorgan failure.
The impact of COVID-19 on patients with pre-existing kidney impairment, including those with chronic kidney disease (CKD), kidney transplant recipients, and individuals on hemodialysis (HD) has not yet been clearly established. No specific treatments for COVID-19 have been found yet.
Renal (kidney) involvement in COVID-19 (coronavirus-nephropathy) has a complex etiology (causes). AKI in COVID-19 is strongly associated with higher mortality and morbidity and is an indicator for survival with coronavirus infection.
According to a prospective cohort study, 44 percent of COVID-19 patients had proteinuria and 27 percent had hematuria at hospital admission, while five percent of patients experienced AKI during in-hospital. Patients with kidney disease had a significantly higher risk of death.
Since the coronavirus outbreak in China at the end of 2019, increasing interest emerged regarding renal involvement during COVID-19 infections. AKI, with or without proteinuria, is described in a variable percentage of patients with COVID-19, and several reports outlined an increased mortality risk in those with AKI.
The mechanisms of renal (kidney) injury during COVID-19 are difficult to study due to the interference of several coexisting factors, such as polypharmacy, hypoxia (decreased oxygen in tissue), and cytokine storm (immune response to the virus).
The coronavirus entry into target cells is facilitated by the presence of angiotensin-converting enzyme 2 (ACE2), a specialized receptor where the virus attaches itself. This is expressed in respiratory cells, as well as renal tubular cells and podocytes, making the hypothesis of a direct renal infection particularly intriguing.
Patients with COVID-19 have displayed kidney damage through AKI, proteinuria, hematuria, edema — swelling in the lower extremities or body, and slight elevation in creatinine (kidney function marker).

AKI
A new comprehensive report shows that people hospitalized with COVID-19 are at significant risk of AKI, which can lead to serious illness, dialysis, and even death.
Acute renal failure (ARF) or AKI occurs when your kidneys suddenly become unable to filter waste products from your blood. When your kidneys lose their filtering ability, dangerous levels of wastes may accumulate, and your blood’s chemical makeup may get out of balance.
This develops rapidly, usually in less than a few days. Acute kidney failure is most common in people who are already hospitalized, particularly in critically ill people who need intensive care.
ARF/AKI can be fatal and requires intensive treatment. However, acute kidney failure may be reversible. If you’re otherwise in good health, you may recover normal or nearly normal kidney function.
AKI normally happens as a complication of another serious illness. It’s not the result of a physical blow to the kidneys, as the name might suggest.
This type of kidney damage is usually seen in older people who are unwell with other conditions and the kidneys are also affected. It’s essential that AKI is detected early and treated promptly.
Without quick treatment, abnormal levels of salts and chemicals can build up in the body, which affect the ability of other organs to work properly. If the kidneys shut down completely, this may require temporary support from a dialysis machine, or lead to death.

Symptoms
Symptoms of AKI include feeling sick or being sick, diarrhea, dehydration, urinating less than usual, confusion and drowsiness.
Even if it does not progress to complete kidney failure, AKI needs to be taken seriously. It has an effect on the whole body, changes how some drugs are handled by the body, and could make some existing illnesses more serious.
AKI is different from chronic kidney disease, where the kidneys gradually lose function over a long period of time.

Who’s at risk
You’re more likely to get AKI if:
— you’re aged 65 or over.
— you already have a kidney problem, such as chronic kidney disease.
— you have a long-term disease, such as heart failure, liver disease or diabetes.
— you’re dehydrated or unable to maintain your fluid intake independently.
— you have a blockage in your urinary tract (or are at risk of this).
— you have a severe infection or sepsis.
— you’re taking certain medicines, including non-steroidal anti-inflammatory drugs (NSAIDS, such as ibuprofen or motrin, diclofenac, advil, excedrin, tylenol 3) or blood pressure drugs, such as ACE inhibitors or diuretics; diuretics are usually beneficial to the kidneys, but may become less helpful when a person is dehydrated or suffering from a severe illness.
— you’re given aminoglycosides – a type of antibiotic; again, this is only an issue if the person is dehydrated or ill, and these are usually only given in a hospital setting.

Article submitted as part of the Ministry of Health’s COVID-19 public information and education programme. For questions, email [email protected].