Men are consistently overrepresented in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and coronavirus disease 2019 (COVID-19) severe outcomes, including higher fatality rates. These differences are likely due to gender-specific behaviors, genetic and hormonal factors, and sex differences in biological pathways related to SARS-CoV-2 infection. Several social, behavioral, and comorbid factors are implicated in the generally worse outcomes in men compared with women. Underlying biological sex differences and their effects on COVID-19 outcomes, however, have received less attention. The present review summarizes the available literature regarding proposed molecular and cellular markers of COVID-19 infection, their associations with health outcomes, and any reported modification by sex. Biological sex differences characterized by such biomarkers exist within healthy populations and also differ with age-and sex-specific conditions, such as pregnancy and menopause. In the context of COVID-19, descriptive biomarker levels are often reported by sex, but data pertaining to the effect of patient sex on the relationship between biomarkers and COVID-19 disease severity/outcomes are scarce. Such biomarkers may offer plausible explanations for the worse COVID-19 outcomes seen in men. There is the need for larger studies with sex-specific reporting and robust analyses to elucidate how sex modifies cellular and molecular pathways associated with SARS-CoV-2. This will improve interpretation of biomarkers and clinical management of COVID-19 patients by facilitating a personalized medical approach to risk stratification, prevention, and treatment.

Background The objective of this case cohort study was to describe our experience in the care of patients with immune checkpoint inhibitor-related acute interstitial nephritis (ICI-AIN) including rechallenge. Methods A descriptive case series of patients that received an ICI and had an AKI (defined as a $1.5-fold increase in serum creatinine) as an immune-related adverse event (irAE), with biopsy-proven or clinically suspected ICI-AIN from January 1, 2014 to December 1, 2018 at Mayo Clinic, Rochester. We studied details regarding diagnosis, clinical course, management, and outcomes of rechallenge of immunotherapy. Complete response (CR) was defined as return of kidney function back to baseline or ,0.3 mg/dl above baseline creatinine; partial response (PR) was defined as creatinine .0.3 mg/dl from baseline, but less than twofold above the baseline by the end of steroid course. Results A total of 14 cases of biopsy-proven (35%) or clinically suspected (65%) ICI-AIN was identified. All patients had their ICI withheld and 12 patients received steroids. Steroid regimens were highly variable. The starting equivalent dose of prednisone was higher in those that had a CR versus a PR (median 0.77 mg/kg versus 0.66 mg/kg). Proton pump inhibitors (PPIs) were used in 11 patients and were stopped in eight (73%) patients at the time of the AKI event. A CR was seen in five (63%) of the eight patients who discontinued PPIs. Rechallenge was attempted in four of the 14 patients: three were successful with no recurrence of AKI, but one patient had recurrent AKI and fatal pneumonitis. Conclusions Careful review, withholding ICI and concomitant known AIN-inducing medications, along with prompt initial steroid management were the key in complete renal kidney recovery. A kidney biopsy should be strongly considered. Rechallenge of immunotherapy after a kidney irAE, although challenging, is possible and would need careful evaluation on an individual basis.

Background Microhematuria is common in immunoglobulin A nephropathy (IgAN). However, current prognostication is based on proteinuria and mesangial hypercellularity, endocapillary hypercellularity, segmental sclerosis, tubulointerstitial fibrosis and crescent (MEST-C) scores. Methods In this retrospective study, we evaluated whether MEST-C score components are associated with the presence of microhematuria at biopsy and whether the degree of microhematuria during follow-up is associated with change in estimated glomerular filtration rate (eGFR), after adjusting for clinical and histological parameters. We identified 125 patients with biopsy-proven IgAN and MEST-C scoring who were not on immunosuppressive therapy at biopsy. Microhematuria was defined as ≥3 red blood cells (RBCs)/high-power field (hpf). Results Of the 125 patients, 97 had microhematuria at baseline and were more likely to have M1, E1 and C ≥ 1 lesions (P < 0.05 for all) compared with patients without microhematuria. Of the 125 patients, 72 had follow-up data available. An increase in the degree of microhematuria was significantly associated with an eGFR decline of −0.81 mL/min/1.73 m2 [95% confidence interval (CI) −1.44 to −0.19, P = 0.01], after adjusting for follow-up time, proteinuria and T score. Severe microhematuria (≥21 RBCs/hpf) was associated with an even larger decline in eGFR (−3.99 mL/min/1.73 m2; 95% CI −6.9411 to −1.0552, P = 0.008), after similar adjustments. Conclusion Degree of microhematuria during follow-up is an independent predictor of eGFR decline after adjusting for clinical and histological parameters. Therefore, monitoring the degree of microhematuria as well as proteinuria is important when evaluating patients with IgAN. Additional studies using improvement in microhematuria as a primary surrogate outcome are needed.

Background: Preeclampsia is a pregnancy-specific hypertensive disorder characterized by proteinuria and/or multisystem involvement. Disease-specific therapy has yet to be developed due to the lack of understanding of underlying mechanism(s). We postulate that accelerated ageing in general, and particularly cellular senescence, play a role in its pathophysiology. Methods: We compared women with preeclampsia vs. normotensive pregnancies with respect to epigenetic markers of ageing and markers of senescence in tissues/organs affected by preeclampsia (blood, urine, adipose tissue, and kidney). Findings: We demonstrate that preeclamptic compared to normotensive pregnant women: (i) undergo accelerated epigenetic ageing during pregnancy, as demonstrated by an "epigenetic clock"; (ii) exhibit higher levels/expression of senescence-associated secretory phenotype factors in blood and adipose tissue; (iii) display increased expression of p16 INK4A in adipose tissue and renal sections, and (iv) demonstrate decreased levels of urinary a-Klotho (an anti-ageing protein) at the time of delivery. Finally, we provide data indicating that pre-treatment with dasatinib, a senolytic agent, rescues the angiogenic potential of mesenchymal stem cells (MSC) obtained from preeclamptic pregnancies, and promotes angiogenesis, even under pro-inflammatory conditions. Interpretation: Taken together, our results identify senescence as one of the mechanisms underpinning the pathophysiology of preeclampsia. Therapeutic strategies that target senescent cells may offer novel mechanism-based treatments for preeclampsia.

Citations are an important, but often overlooked, part of every scientific paper. They allow the reader to trace the flow of evidence, serving as a gateway to relevant literature. Most scientists are aware of citations errors, but few appreciate the prevalence of these problems. The purpose of this study was to examine how often frequently cited papers in biomedical scientific literature are cited inaccurately. The study included an active participation of first authors of included papers; to first-hand verify the citations accuracy. Findings from feasibility study, where we reviewed 1,540 articles containing 2,526 citations of 14 most cited articles in which the authors were affiliated with the Faculty of Medicine University of Belgrade, were further evaluated for external confirmation in an independent verification set of articles. Verification set included 4,912 citations identified in 2,995 articles that cited 13 most cited articles published by authors affiliated with the Mayo Clinic Division of Nephrology and Hypertension. A citation was defined as being accurate if the cited article supported or was in accordance with the statement by citing authors. At least one inaccurate citation was found in 11% and 15% of articles in the feasibility study and verification set, respectively, suggesting that inaccurate citations are common in biomedical literature. The most common problem was the citation of nonexistent findings (38.4%), followed by an incorrect interpretation of findings (15.4%). One fifth of inaccurate citations were due to chains of inaccurate citations. Based on these findings, several actions to reduce citation inaccuracies have been proposed.