COVID-19: the risks for patients with renal failure and prevention strategies

COVID-19: the risks for patients with renal failure and prevention strategies

COVID-19 also damages the kidneys, with different mechanisms and consequences. And it is therefore a problem that needs to be kept in mind both clinically and organizationally to cope adequately, as it is far from rare. A Chinese study found that half of those hospitalized for COVID-19 have protein or blood in their urine, an obvious sign of kidney damage.

Fourteen to 30 percent of patients with COVID-19 admitted to intensive care in Wuhan and New York also had deterioration of renal function such that they required hemodialysis treatment. This is the reason why intensive care units in New York rushed to urgently ask for more specialized dialysis staff, with the added incubation of being without dialysis fluids.

Frequent kidney damage in patients with covid-19

Kidney damage in Covid-19 patients is far from uncommon. And it has been known for almost a year now: that’s how long it has been since the first evidence put on paper by Chinese researchers, by which it was shown that nearly half of those hospitalized due to the disease caused had protein or blood in their urine. A clear sign of kidney injury, confirmed in the months to follow by several studies: the latest of which has just been published in the journal Jama Network Open. In general,acute renal failure is estimated to appear in between 24 and 57 percent of patients admitted to pulmonary, infectious disease and general medicine wards. But it can be as high as 80 percent among those requiring respiratory support in intensive care. The deficit in activity of the two organs among those found to be struggling with Covid-19 is more pronounced than in the rest of the population. This is confirmed by the greater use of dialysis and, more generally, the higher risk of going into chronicrenal failure (chronic renal failure). An aspect understood as the weeks go by, which has led to making the figure of the nephrologist (also) neuralgic in the care of these patients.

The mechanisms underlying kidney damage

But what are the mechanisms by which the virus can damage the kidneys? “Sars-CoV-2 has been detected at the level of both tubules and renal epithelium in several patients who have died from Covid-19,” explains Giuseppe Grandaliano, director of the complex operating unit of nephrology at Policlinico Gemelli in Rome. This is not surprising, considering that ACE2 receptors abound in the kidneys (up to 100 times as many as those found in lung tissue), the gateway for the virus to enter cells. To this must be added an indirect effect, brought about by the widespread inflammatory response (cytokine storm) responsible for the worsening condition of these patients. “Again through autopsies, traces of the cells involved in the inflammatory response have been detected at the renal level,” Grandaliano continues. ”To this it should be added that the proinflammatory cytokines that result diffused in the bloodstream can cause hypoxia and rhabdomyolysis. A condition, the latter, that results in widespread muscle damage, with the release of the enzyme creatine phosphokinase into the bloodstream. Its accumulation is toxic to our body’s “filters. And, as such, capable of leading to acute renal failure even within 48 hours.

Chronic renal failure “complicates” covid-19

Acute renal failure is thus likely to be one more “enemy” to face in the hospital, for patients already struggling with impaired respiratory function from Covid-19. To this must be added that those who overcome the disease, if they have had to deal with kidney damage, are then called upon to keep their activity under control for some time (depending on the severity of the insufficiency found). So far, these are the signs that Covid-19 is likely to leave on the kidneys. But the relationship between the organs in which urine production takes place and the disease caused by Sars-CoV-2 is more multifaceted. And it also calls into question the fragility to which those already suffering from kidney failure who are infected with the coronavirus are exposed. According to a survey conducted by the Italian Society of Nephrology during the second wave, patients with chronic kidney disease (a condition more common in the presence of hypertension, type 2 diabetes and obesity) live with an increased risk of becoming infected. And, in that case, the disease is accompanied by increased lethality.

Higher risks for dialysis and kidney transplant recipients

As of October to date, a quarter of these patients have died from Covid-19 complications. This is 8-10 times higher than the average rate for the general population. Those most at risk are considered to be dialysis and kidney transplant recipients, who are forced to follow lifelong immunosuppressive therapy. A condition that affects nearly one hundred thousand people, in Italy. Explains Piergiorgio Messa, director of the complex operating unit of nephrology, dialysis and renal transplantation at the Policlinico di Milano: “Patients on dialysis and those who have received a kidney transplant are more susceptible to contracting the infection. More importantly, when infected they have a higher risk of dying than the general population.”

Covid-19 vaccinate these patients as soon as possible

Specifically, the most exposed, especially in the first wave, were patients forced to undergo dialysis in the hospital. Spending hours, both while waiting and during treatment, in common environments at higher risk of infection. Yes thus explains the call to vaccinate these patients as soon as possible. “It is evident that the ratio of nephropathic positive patients, dialysis and transplanted patients, and the number of deaths remained constant between the first and second waves,” concludes Messa, who chairs the Italian Society of Nephrology. ”The vaccination plan must consider immunization of these patients who are particularly fragile due to exposure to infection, presence of other diseases and consequent high lethality as a priority.