Iranian Journal of Kidney Diseases
Volume:15 Issue: 4, Jul 2021

Coronavirus disease 2019 (COVID‑19) was identified in December 2019 and is still expanding in most parts of the world. The wide variety of affected organs is likely based upon the shared expression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) important entry-receptor angiotensin-converting enzyme 2 (ACE2). For this reason, the broad distribution of ACE2 receptors in different tissues plays a crucial role in the multi-organ dysfunction and fatality due to COVID-19. Because of the high prevalence of acute kidney injury (AKI) in patients with COVID-19, we review the molecular understanding into viral infection mechanisms and implications for AKI. Furthermore, mechanisms of the AKI to chronic kidney disease (CKD) progression, such as the relative contribution of immune cell reaction, fibroblasts activation, endothelial dysfunction, and subsequent hypoxia may contribute to the association of AKI with worse outcomes during this virus pandemic. We highlight the state of the knowledge on SARS-CoV-2-dependent mechanisms for AKI and list the potential management choices for the prevention of AKI aggravation and the impending possibility of CKD. Finally, we intend to provide a much better understanding of why Coronavirus induces AKI and its subsequent progression to CKD in the coming years and further discuss the acute and long-term renal consequences.

Many factors, such as increased serum creatinine, increased blood pressure and abnormal urine protein, may lead to poor prognosis of IgA nephropathy (IgAN). The features of IgAN are also affected by uric acid, but its effect on the prognosis is less reported. We therefore systematically investigated the possible correlation of IgAN with hyperuricemia (HUA) and their prognosis.

Methods

Two groups (HUA group and uric acid normal group) were included of 178 IgAN patients. The indexes in the clinic and pathology were compared; logistic regression and renal survival were used to speculate the correlated factors of HUA in IgAN and their prognosis.

HUA group had higher serum urea nitrogen, serum creatinine, total cholesterol, 24-hour urinary protein quantity, percentage of CKD3⁃5, the thickness of arteriole, glomerular mesangial hyperplasia, tubular atrophy, glomerulosclerosis, interstitial fibrosis and the area of infiltration of inflammatory cells (ICI), lower eGFR and serum albumin-to-creatinine ratios (P < .05). Total cholesterol and ICI in X2 were independent related factors of HUA given by the analysis of logistic regression (P < .05). No correlation was found in HUA and normal group used by Kaplan– Meier (P > .05).

Severer renal pathological injures (glomeruli, tubules or interstitium) were found in IgAN. Besides, total cholesterol and the area of infiltration of inflammatory cells were independent related factors of hyperuricemia in IgAN.

To study the prevalence of vitamin D deficiency in kidney stone formers and its predisposing factors and to assess the relationship between serum 25-Hydroxyvitamin D and urine metabolites.

Kidney stone formers were selected from the records of the kidney stone prevention clinic in Labbafinejad hospital, Tehran, Iran. Vitamin D deficiency was defined as 25-Hydroxyvitamin D < 20 ng/mL. The association between vitamin D deficiency and predisposing factors, serum, and urine metabolites was evaluated.

In 1005 patients (66.4% men and 33.6% women), the prevalence of vitamin D deficiency was 44.8%. Vitamin D deficiency was more prevalent in patients under 50 years (P < .001) and patients with hyperparathyroidism (P < .05). The lowest prevalence of hyperparathyroidism was in the 25-Hydroxyvitamin D range of 40 to 49.9 ng/mL, followed by the range of 30 to 39.9 and 20 to 29.9 ng/mL. Patients with vitamin D deficiency had lower serum creatinine (P < .02), lower 24-hour urine calcium (P < .01), and lower 24-hour urine oxalate (P < .05).

Iranian kidney stone formers have a relatively high prevalence of vitamin D deficiency. Our population seems to have different predisposing factors for vitamin D deficiency, i.e., higher prevalence among younger patients and no association between obesity and gender with vitamin D status. According to the parathyroid hormone, the favorable serum 25-Hydroxyvitamin D level was 20 to 49.9 ng/mL in our kidney stone formers.

Diabetic nephropathy (DN) is a major complication of diabetes Mellitus. Early detection and intervention of DN can slow its progression and improve patients’ outcomes. Neutrophil gelatinase-associated lipocalin (NGAL) as a marker of tubular damage might become a useful biomarker for the evaluation of renal involvement in diabetic patients. We aimed to evaluate the serum and urine NGAL(s-NGAL and u-NGAL) in type 2 diabetic patients and its correlation with different stages of diabetic nephropathy.

This cross-sectional study was designed on 198 subjects consisted of 50 controls and 148 type 2 diabetes patients (50 normoalbuminuric, 58 microalbuminuric, and 40 macroalbuminuric). The study was conducted with measuring s-NGAL and u-NGAL, albumin and spot urine creatinine were also measured.

A highly increased level of s-NGAL was detected in macroalbuminuric group compared with controls, normoalbuminurics and microalbuminurics (P < .01). Highly raised u-NGAL levels were observed in macroalbuminurics in comparison with controls (P < .01). ROC curve demonstrated the best sensitivity and specificity of s-NGAL/u-NGAL for the macroalbuminuric state (sensitivity, 26% and 60%; specificity, 98% and 72%; respectively), in which the best cut-off points for the detection of macroalbuminuric state for s-NGAL/u-NGAL were 300 ng/mL and 71.4 ng/mL, respectively.

Serum and urine-NGAL are elevated in type 2 diabetic patients, with or without albuminuria, s-NGAL level clearly correlates with severity of renal damage caused by DN and u-NGAL increases in macroalbuminuric state. S-NGAL could be a useful, noninvasive, available and practical test for evaluation of diabetic renal involvement. We could suggest u-NGAL as a probable predictor of macroalbuminuria.

Coronavirus disease 19 (COVID-19), has recently emerged as a great health challenge. The novel corona virus may affect the kidneys mainly as acute kidney injury (AKI). Also, the outcome of COVID-19 may be different in patients with underlying kidney disease. The aim of this study was to compare the outcome of COVID-19 in patients with and without underlying kidney disease.

This was a retrospective study on 659 hospitalized COVID-19 patients in six centers of Iran. Patients were classified into kidney (chronic kidney disease (CKD), end-stage kidney disease (ESKD) or kidney transplantation) and non-kidney groups. The clinical conditions and laboratory data were extracted from the charts. Outcome was defined as death during hospitalization or within 30 days of discharge.

Among 659 COVID-19 patients (mean age: 60.7 ± 16.4, 56% male), 208 were in the kidney group (86 ESKD, 35 kidney transplants, and 87 CKD patients). AKI occurred in 41.8%. Incidence of AKI was 34.7% in non-kidney, 74.7% in CKD, and 51.4% in kidney transplant patients (P < .001). Totally 178 patients (27%) died and mortality rate was significantly higher in CKD patients (50.6 vs. 23.4%, P < .001). AKI was associated with increased mortality rate (OR = 2.588, CI: 1.707 to 3.925). Initial glomerular filtration rate (GFR) < 44.2 mL/min and elevated lactate dehydrogenase (LDH) and C-reactive protein (CRP) had significant association with mortality.

We showed a higher mortality rate in COVID-19 patients with AKI and CKD. Low initial GFR and elevated LDH and CRP were associated with high mortality in COVID-19 patients.

Angiotensin receptor neprilysin inhibitor (ARNI) has been recommended by major guidelines as the leading therapy for heart failure with reduced ejection fraction (HFrEF). But little is known about its safety and effectiveness among maintenance hemodialysis patients with HFrEF in real-word practice.

An observational study was conducted among maintenance hemodialysis patients who received ARNI at our dialysis center. Enrollment commenced on June 1, 2018; and follow-up was completed on May 31, 2019.

A total of 110 patients included in the study (age: 54.2 ± 14.8 y, 59% males). After 12 months of treatment, the average ARNI daily dose increased from 135 mg to 308 mg. The mean NT-proBNP concentration at baseline was 14455 pg/mL and 6435 pg/ mL after 12 months of treatment (P < .001). The left ventricular ejection fraction improved (35.1 vs. 49.8%, P < .001) over the 12 months, while left ventricular end-diastolic diameter, left ventricular mass index, left ventricular end-systolic diameter, and left atrial diameter also changed significantly (167.8 vs. 154.9 g/m, P < .001; 52.2 vs. 51.5 mm, P < .05; 35.9 vs. 36.9 mm, P < .001; 42.2 vs. 40.3 mm, P < .001). Furthermore, we found the quality of life and the NYHA symptom severity class improved significantly (P < .001). Kaplan-Meier analysis indicated that higher dose of ARNI and less vintage of HD were associated with best survival.

In our study, ARNI appeared to be safe, relieved heart failure symptoms, and improved the scores of KCCQ physical and social activities in hemodialysis patients in real-world practice.

Pulmonary artery hypertension (PAH) is common in end stage renal disease (ESRD) patients undergoing hemodialysis. Fibroblast growth factor-23 (FGF-23) increases in hemodialysis but its relationship with PAH is not completely understood. The aim of this study was to evaluate the relation between FGF-23 level and development of PAH in ESRD patients undergoing hemodialysis.

Patients undergoing hemodialysis for more than 6 months were enrolled in this cross-sectional study. Transthoracic echocardiography was performed to measure ejection fraction and pulmonary artery pressure (PAP) in all patients. Patients were grouped into normal PAP (PAP < 25 mmHg), elevated PAP (25 < PAP < 35 mmHg) and PAH (PAP > 35 mmHg). Parathormone hormone, calcium, phosphorus, vitamin D, and hemoglobin levels were also evaluated.

Eighty-five patients (48 male, 56.47%) enrolled in this study. The mean age of the patients was 51.05 ± 16.45 years. Most of the patients (49, 57.65%) had normal PAP, 20 (23.53%) had elevated PAP and 16 (18.82%) had PAH. Serum biochemical markers and demographic characteristics were not significantly related to different PAP values (P > .05). Most of the patients (42, 49.41%) had normal FGF-23 levels. There was a significant relationship between PAP groups and FGF-23 and parathormone levels, P < .001, and P < .05; respectively. FGF-23 was significantly higher in PAH and elevated PAP groups compared with normal PAP group (P < .05). Only a significant positive correlation was observed between FGF-23 levels and PAP (P < .001).

This finding highlights the possible role of FGF-23 in the development of vascular complications in ESRD patients.

Although several investigators have reported the relationship between bone mineral density (BMD) and mortality in patients on hemodialysis, it is unclear BMD of which site is most strongly associated with mortality.

We examined the factors related to fractures in patients on hemodialysis in 2009. Based on these data, we investigated the influence of BMD of different sites on mortality in this cohort of 81 patients on hemodialysis. BMD was measured at the distal third of the radius (1/3 Rad), lumbar spine, and total hip. Fifteen patients had prevalent vertebral fractures and seven had prevalent hip fractures. The influences of age, body mass index (BMI), serum creatinine (Cr), serum albumin (Alb), dialysis vintage, and parathyroid hormone (PTH, measured as whole PTH) on mortality were also studied.

Fifty-two patients died by August 31, 2018. BMD was significantly higher in the survival group than in the deceased group only for the 1/3 Rad group (P < .001). Although patients with prevalent hip or vertebral fractures showed a higher mortality rate than those without fractures, no significant difference was observed. In the deceased group, age was significantly higher, and BMI and Cr levels were significantly lower than those in the survival group (P < .001, P < .05, and P < .01; respectively). After adjustment for these parameters, BMD of the 1/3 Rad remained a significant prognostic factor.

Although this was a study with a limited number of patients, BMD of the 1/3 Rad appears to be associated with mortality in patients on hemodialysis.

Overhydration (OH) remains a recurrent problem in peritoneal dialysis (PD), with deleterious effect in outcomes. Recent evidence suggests a direct relation between OH and increased peritonitis risk. The mechanisms of this connection are not well defined, but gut wall edema and malnutrition are probably involved.

Our aim was to assess OH as a risk factor for peritonitis in patients on PD. Retrospective study was done in a PD program with a bio impedance analysis. The investigator reviewed patient charts and documents. The Fresenius® Body Composition Monitor was used to obtain hydration parameters. OH was considered when Overhydration/Extracellular Water (OH/ECW) parameter was over 15% of the dry weight. The diagnosis of peritonitis was made according to the International Society of Peritoneal Dialysis guidelines. Associations between peritonitis rate and the collected variables were assessed using Chi-square test and Pearson’s correlation.

An association between OH and the risk of peritonitis was established.

OH is prevalent in our patients undergoing PD and it is a modifiable risk factor for peritonitis. The bio impedance analysis is economical and should be used in association with a physical exam and treatment results to achieve the normo-hydrated status in those patients.

Rapid-onset obesity with hypoventilation, hypothalamic dysfunction, and autonomic dysregulation (ROHHAD) syndrome is a rare, life threatening disease with unknown etiology. Dysnatremia is a common finding in these patients. Here we present a 12-year-old boy with multiple admissions due to hypernatremia and was repeatedly misdiagnosed. An eventual diagnosis of ROHHAD syndrome was made by integration of the previous ignored findings of sleep apnea and obesity. The diagnosis of this rare but potentially fatal syndrome should be considered in patients with dysnatremia associated with obesity and sleep apnea disorders.