A meta-analysis on diagnostic value of serum cystatin C and creatinine for the evaluation of glomerular filtration function in renal transplant patients

Urinary N-Acetyl-Beta-D-Glucosaminidase levels predict immunoglobulin a nephropathy remission status

BACKGROUND

Tubulointerstitial lesions play a pivotal role in the progression of IgA nephropathy (IgAN). Elevated N-acetyl-beta-D-glucosaminidase (NAG) in urine is released from damaged proximal tubular epithelial cells (PTEC) and may serve as a biomarker of renal progression in diseases with tubulointerstitial involvement.

METHODS

We evaluated the predictive value of urinary NAG (uNAG) for disease progression in 213 biopsy-proven primary IgAN patients from January 2018 to December 2019 at Zhongshan Hospital, Fudan University. We compared the results with those of serum cystatin C (sCysC).

RESULTS

Increased uNAG and sCysC levels were associated with worse clinical and histological manifestations. Only uNAG level was independently associated with remission status after adjustment. Patients with high uNAG levels (> 22.32 U/g Cr) had a 4.32-fold greater risk of disease progression. The combination of baseline uNAG and clinical data may achieve satisfactory risk prediction in IgAN patients with relatively preserved renal function (eGFR ≥ 60 ml/min/1.73 m2, area under the curve [AUC] 0.760).

CONCLUSION

Our results suggest that uNAG is a promising biomarker for predicting IgAN remission status.

Microchimerism as Post-Transplant Marker of a Chronic Rejection Process

The risk of losing a transplanted organ is high, and non-invasive markers to warn of this phenomenon are still being sought. We investigated the impact of post-transplant microchimerism on the function of the transplanted kidney. The study included 100 kidney transplant recipients, mostly women. All transplanted organs were from opposite-sex deceased donors. Microchimerism was assessed using multiplex PCR. Male DNA was detected in all urine samples from female recipients and in 13/56 blood samples from female kidney recipients. Female DNA was found in 31/44 urine samples from male recipients, but in none of the blood samples. Microchimerism in the urine of female recipients correlated positively with blood urea (Rs = 0.45; p = 5.84 × 10^-4) and K⁺ ions (Rs = 0.29; p = 0.03), while microchimerism in the blood of female recipients also correlated positively with blood urea (Rs = 0. 28; p = 0.04), cystatin C (Rs = 0.31; p = 0.02) and the number of incompatible HLA alleles (Rs = 0.42; p = 0.01). A history of DGF was associated with higher urinary donor DNA concentrations in female recipients.: Post-transplant microchimerism may serve as a potential marker of chronic kidney rejection.

The Perspectives of Biomarkers in Predicting the Survival of the Renal Graft

Kidney transplantation (KT) is currently the elective approach for patients with end-stage renal disease. Although it is a safe choice for these patients, the early complications can lead to graft dysfunction. One of the most redoubtable complications is delayed graft function (DGF), having no specific treatment. The effects of DGF on the graft survival are large enough to justify the formulation of specific biological protocols. Therefore, discovering biomarkers of acute impairment in renal transplanted patients is required. Creatinine is a poor marker to establish the kidney injury. Estimated glomerular filtration rate together with creatinine is ready to approximately measure the kidney function. Different serum and urine proteins are being studied as possible predictive biomarkers for delayed graft function. This review will concentrate on recent and existing research which provide insight concerning the contribution of some molecules for the estimation and evaluation of graft function after kidney transplantation. Further studies examining various aspects of DGF after KT are urgently needed to address a hitherto less-known clinical question.

NIR-Responsive Spatiotemporally Controlled Cyanobacteria Micro-Nanodevice for Intensity-Modulated Chemotherapeutics in Rheumatoid Arthritis

The expression of hypoxia-inducible factor-1α (HIF-1α) is upregulated in hypoxic environments at the lesions of rheumatoid arthritis (RA), which promoted the polarization of proinflammatory M1 macrophages and inhibited the differentiation of anti-inflammatory M2 to deteriorate synovial inflammation. Since oxygen scarcity at the joints causes an imbalance of macrophages M1 and M2, herein, we designed a cyanobacteria micro-nanodevice that can be spatiotemporally controlled in vivo to continuously producing oxygen in the RA joints for the downregulation of the expression of HIF-1α, thereby reducing the amounts of M1 macrophages and inducing the polarization of M2 macrophages for chemically sensitized RA treatment. The forthputting of temperature-sensitive hydrogel guaranteed the safety of cyanobacteria micro-nanodevice in vivo. Furthermore, the oxygen produced by cyanobacteria micro-nanodevice in a sustained manner enhanced the therapeutic effect of the antirheumatic drug methotrexate (MTX) and discouraged inflammation and bone erosion at RA. This study provided a new approach for the RA treatment of spatiotemporal-controlled release of oxygen in vitro.

Leucocytosis and Asymptomatic Urinary Tract Infections in Sickle Cell Patients at a Tertiary Hospital in Zambia

Sickle cell anaemia (SCA) is an inherited disease resulting from mutations in the β-globin chain of adult haemoglobin that results in the formation of homozygous sickle haemoglobin. It is associated with several complications including an altered blood picture and damage in multiple organs, including the kidneys. Kidney disease is seen in most patients with SCA and may affect glomerular and/or tubular function, thereby putting these patients at risk of urinary tract infections. However, there is a paucity of data on the prevalence of urinary tract infections (UTIs) among SCA patients in Zambia. This study aimed to determine the prevalence of UTIs and haematological and kidney function profiles among SCA patients at the University Teaching Hospitals, Lusaka, Zambia. This was a cross-sectional study conducted between April and July 2019 involving 78 SCA patients who presented at the UTH. Blood and midstream urine samples were collected from each participant using the standard specimen collection procedures. Full blood counts and kidney function tests were determined using Sysmex XT-4000i haematology analyser and the Pentra C200 by Horiba, respectively. Bacterial profiles of the urine samples were determined using conventional microbiological methods. We found that all the measured patients' haemoglobin (Hb) levels fell below the WHO-recommended reference range with a minimum of 5 g/dl, a maximum of 10.5 g/dl, and a mean of 8 ± 1 g/dl. Fifty percent of the participants had moderate anaemia, while the other 50% had severe anaemia. The minimum WBC count of the participants was 0.02 × 10⁹/L with a maximum of 23.36 × 10⁹/L and a mean of 13.48 ± 3.87 × 10⁹/L. Using the one-way analysis of variance test, we found no significant difference in mean WBC count and Hb concentration across various age-group categories that we defined. Bacteriuria was found in 25% of participants. The most common bacterial isolates were Staphylococcus aureus (32%) and coagulase-negative Staphylococci (32%). Klebsiella pneumoniae was 16%. We found no significant association between bacterial isolates and white blood cell count, age groups, sex, and anaemia severity p = 0.41. None of the participants were diagnosed with kidney disease. There was a high prevalence of asymptomatic UTIs among SCA patients at UTH, which, when coupled with the marked leukocytosis and anaemia, may negatively impact the clinical outcome of the patients. Therefore, we recommend close monitoring of sickle cell patients in Zambia for such conditions to improve patients' outcomes.

Differential MicroRNA Expressions in Human Peripheral Blood Mononuclear Cells Are Predictive of Renal Allograft Function

BACKGROUND

The present diagnostic methods for detecting graft damage after kidney transplantation are either invasive or not available early enough. The microRNAs (miRNAs) in peripheral blood mononuclear cells (PBMCs) have been suggested as promising biomarkers.

METHODS

Using quantitative real-time polymerase chain reaction, we identified 9 miRNAs (miR-142-5p, miR-142-3p, miR-223, miR-211, miR-486, miR-155, miR-10b, miR-30a, and let-7c) related to the human renal allograft status in PBMCs from 104 kidney transplant recipients.

RESULTS

The miR-142-5p, miR-142-3p, and miR-223 were significantly upregulated and miR-10b was significantly downregulated in recipients with abnormal levels of serum creatinine 3 to 4 weeks after initial sample collection. Moreover, the miR-142-5p and miR-142-3p were also found to be significantly upregulated in recipients with abnormal levels of cystatin C. Through a combination of the validated miRNAs, receiver operating characteristic analyses yielded the highest area under the curve value of 0.7913 and 0.7063 in predicting the levels of serum creatinine and cystatin C, respectively. In the testing stage, the developed models correctly predicted allograft function in 16 to 17 of 22 recipients (false rate, 22.7%-27.2%).

CONCLUSIONS

miRNAs in PBMCs of recipients hold great promise to be used as predictive and noninvasive biomarkers after transplantation.

[Correlation of blood concentration of tacrolimus with serum cystatin C in renal transplant recipients and effect of tacrolimus on glucose and lipid metabolism]

OBJECTIVE

To investigate the correlation between blood concentrations of tacrolimus (FK506) and cystatin C (Cys C) and the effect of FK506 on glycolipid metabolism in renal transplant recipients.

METHODS

A total of 325 patients receiving renal transplantation between August, 2014 and September, 2015 in Nanfang Hospital were divided into 4 groups according to the postoperative time (1 month group, 1-3 months group, 4-6 months group, and 7-12 months group). FK506 blood trough concentration was measured at the time of postoperative follow-up, and creatinine (Scr) and Cys C levels were also detected. Results Plasma FK506 concentration decreased with age in the recipients and showed a positive correlation with Cys C (r=0.985, P=0.015) but no obvious correlation with Scr (r=0.259, P=0.741). FK506 had no effect on blood glucose (5.53-5.59 mmol<L) or blood lipids (TG 1.47-1.55 mmol<L, TC 5.04-5.17 mmol<L, LDL-C 3.00-3.07 mmol<L, and VLDL 0.73-0.76 mmol<L) in patients 1-6 months after renal transplantation.

CONCLUSION

FK506 does not affect the level of glycolipid metabolism in patients after renal transplantation. Cys C is positively related to blood concentration of FK506 in the renal transplantation recipients. The rational use of FK506 can improve the effectiveness and safety of the treatment in the recipients.

Cystatin C and cardiovascular or all-cause mortality risk in the general population: A meta-analysis

BACKGROUND

Elevated cystatin C level was associated with excessive risk of cardiovascular events and mortality in the highly cardiovascular risk populations. We conducted this meta-analysis to investigate the relationship between serum cystatin C level and cardiovascular or all-cause mortality risk in the general population.

METHODS

We searched for all relevant studies published through May 2015 using PubMed, Embase, and Cochrane Library. Prospective studies that assessed the relationship between serum cystatin C level and cardiovascular or all-cause mortality risk in the general population were selected. Pooled adjust hazard risk (HR) and the corresponding 95% confidence intervals (CI) were calculated for continuous and category of cystatin C level.

RESULTS

Nine studies composed of 38,854 participants were analyzed. Elevated serum cystatin C level was associated with excessive risk of all-cause mortality (HR 1.72; 95% CI 1.37-2.16) and cardiovascular mortality (HR 2.74; 95% CI 2.04-3.68) comparing the highest to lowest category of cystatin C. Each standard deviation increment in serum cystatin C level increased 32% all-cause (HR 1.32; 95% CI 1.12-1.55) and 57% cardiovascular mortality (HR 1.57; 95% CI 1.31-1.88) risk.

CONCLUSIONS

Elevated serum cystatin C level is independently associated with excessive cardiovascular and all-cause mortality risk in elderly persons.