Acute kidney injury: Steroids for prevention of AKI after cardiopulmonary bypass

Protective mechanisms of Leontopodium leontopodioides extracts on lipopolysaccharide-induced acute kidney injury viathe NF-κB/NLRP3 pathway

Sepsis-induced uncontrolled systemic inflammatory response syndrome (SIRS) is a critical cause of multiple organ failure. Acute kidney injury (AKI) is one of the most serious complications associated with an extremely high mortality rate in SIRS, and it lacked simple, safe, and effective treatment strategies. Leontopodium leontopodioides (Willd.) Beauv (LLB) is commonly used in traditional Chinese medicine for the treatment of acute and chronic nephritis. However, it remains unclear whether lipopolysaccharide (LPS) affects LPS-induced AKI. To identify the molecular mechanisms of LLB in LPS-induced HK-2 cells and mice, LLB was prepared by extraction with 70% methanol, while a lipopolysaccharide (LPS)-induced HK-2 cell model and an AKI model were established in this study. Renal histopathology staining was performed to observe the morphology changes. The cell supernatant and kidney tissues were collected for determining the levels of inflammatory factors and protein expression by ELISA, immunofluorescence, and Western blot. The results indicated that LLB significantly reduced the expression of IL-6 and TNF-α in LPS-induced HK-2 cells, as well as the secretion of IL-6, TNF-α, and IL-1β in the supernatant. The same results were observed in LPS-induced AKI serum. Further studies revealed that LLB remarkably improved oxidative stress and apoptosis based on the content of MDA, SOD, and CAT in serum and TUNEL staining results. Notably, LLB significantly reduced the mortality due to LPS infection. Renal histopathology staining results supported these results. Furthermore, immunofluorescence and Western blot results confirmed that LLB significantly reduced the expression of the protein related to the NF-κB signaling pathway and NLRP3, ASC, and Caspase-1 which were significantly increased through LPS stimulation. These findings clearly demonstrated the potential use of LLB in the treatment of AKI and the crucial role of the NF-κB/NLRP3 pathway in the process through which LLB attenuates AKI induced by LPS.

Early Experience With Methylprednisolone on SARS-CoV-2 Infection in the African American Population, a Retrospective Analysis

BACKGROUND

Coronavirus disease-19 (COVID-19) is associated with acute kidney injury (AKI) and acute respiratory distress syndrome (ARDS) with high mortality rates. In African American (AA) populations, COVID-19 presentations and outcomes are more severe. NIH and Interim WHO guidelines had suggested against the use of corticosteroids unless in clinical trials until the recent publication of the RECOVERY trial. Here, we analyzed the treatment effect of methylprednisolone on patients with AKI and ARDS during the initial 2 months of COVID-19 and detail the learning effect within our institution.

METHODS

Between March 1 and April 30, 2020, 75 AA patients met our inclusion criteria for ARDS and AKI, of which 37 had received corticosteroids. Twenty-eight-day mortality, improvement in PaO2/FiO2 ratio, and renal function were analyzed. The impact of methylprednisolone treatment was assessed with multivariable methods.

RESULTS

Survival in the methylprednisolone group reached 51% at 21 days compared to 29% in the non-corticosteroid group (P < .001). Methylprednisolone improved the likelihood of renal function improvement. PaO2/FiO2 ratio in the methylprednisolone group improved by 73% compared to 45% in the non-corticosteroid group (P = .01). Age, gender, BMI, preexisting conditions, and other treatment factors did not show any impact on renal or PaO2/FiO2 ratio improvement. The use of anticoagulants, the month of treatment, and AKI during hospitalization also influenced outcomes.

CONCLUSION

In AA COVID-19 positive patients with ARDS and AKI, IV methylprednisolone lowered the incidence of mortality and improved the likelihood of renal and lung function recovery. Further investigation with a randomized control trial of corticosteroids is warranted.

Targeting acute kidney injury in COVID-19

As of 15 August 2020, Coronavirus disease 2019 (COVID-19) has been reported in >21 million people world-wide and is responsible for more than 750,000 deaths. The occurrence of acute kidney injury (AKI) in patients hospitalized with COVID-19 has been reported to be as high as 43%. This is comparable to AKI in other forms of pneumonia requiring hospitalization, as well as in non-infectious conditions like cardiac surgery. The impact of AKI on COVID-19 outcomes is difficult to assess at present but, similar to other forms of sepsis, AKI is strongly associated with hospital mortality. Indeed, mortality is reported to be very low in COVID-19 patients without AKI. Given that AKI contributes to fluid and acid-base imbalances, compromises immune response and may impair resolution of inflammation, it seems likely that AKI contributes to mortality in these patients. The pathophysiologic mechanisms of AKI in COVID-19 are thought to be multifactorial including systemic immune and inflammatory responses induced by viral infection, systemic tissue hypoxia, reduced renal perfusion, endothelial damage and direct epithelial infection with Severe Acute Respiratory Syndrome Coronavirus 2. Mitochondria play a central role in the metabolic deregulation in the adaptive response to the systemic inflammation and are also found to be vital in response to both direct viral damage and tissue reperfusion. These stress conditions are associated with increased glycolysis and reduced fatty acid oxidation. Thus, there is a strong rationale to target AKI for therapy in COVID-19. Furthermore, many approaches that have been developed for other etiologies of AKI such as sepsis, inflammation and ischemia-reperfusion, have relevance in the treatment of COVID-19 AKI and could be rapidly pivoted to this new disease.

Pretreatment of Huaiqihuang extractum protects against cisplatin-induced nephrotoxicity

Cisplatin is a commonly used chemotherapeutic agent in the treatment of different types of malignant tumors, but nephrotoxicity limits its usage. Therefore, in this study, we aimed to determine the possible protective effect of Huaiqihuang (HQH) extractum, a kind of Chinese herbal complex that consists of Trametes robiniophila Murr., Lycium barbarum and Polygonatum sibiricum, against nephrotoxicity induced by cisplatin in mice. We found that pretreatment with HQH significantly attenuated the cisplatin-induced increase in blood urea nitrogen (BUN), interstitial congestion, acute renal tubular injury and tubular cell apoptosis and necroptosis. It was further shown that HQH administration reduced cisplatin-induced release and nuclear-cytoplasmic translocation of HMGB1 and inactivated its downstream signaling molecules, TLR4 and NFκB, in renal tubular cells; as a result, HQH repressed cisplatin-induced TNF-α production. As dexamethasone (Dex) exerts renoprotective effects in severe Acute kidney injury (AKI), we compared it with HQH and found that HQH showed similar renoprotective effects to dexamethasone via similar mechanisms. Considering the potential side effects of corticosteroids, reducing the effectiveness of treatment and shortening survival in solid tumor patients, we suggest administration of HQH as a potential adjuvant for cisplatin therapy in solid tumor patients to preserve renal function.