NephroCheck® Quality Test

BACKGROUND

The acute kidney injury (AKI) risk score helps detect moderate and severe AKI in the next 12-24 h. However, inappropriate urine collection may impact its results.

AIM

The aim of this study was to evaluate the stability of NephroCheck® after urine storage at different temperatures.

METHODS

The urine sample was centrifuged and split into 3 tubes. One was tested as soon as possible by the laboratory. The other 2 samples were frozen at -20 and -80°C, and the NephroCheck® test was performed 8 weeks later.

RESULTS

The mean values of the AKI risk score were 1.19 ± 0.93, 1.15 ± 1.14, and 1.20 ± 1.11 (ng/mL)2/1,000 for fresh urine, -20, and -80°C, respectively (p = 0.70). Spearman's rank correlation for -20 and -80°C versus immediate processing was strong with a rho of 0.82 and 0.98, respectively.

CONCLUSION

The AKI risk score was relatively stable. Urine could be collected without dry ice or liquid nitrogen and kept for up to 8 weeks with either -20 or -80°C freezing with stable NephroCheck® results.

Reduced urinary levels of angiotensin-converting enzyme 2 activity predict acute kidney injury in critically ill patients

Objective: Angiotensin-converting enzyme 2 activity reflects non-classical renin-angiotensin system upregulation. We assessed the association of urinary angiotensin-converting enzyme 2 (uACE2) activity with acute kidney injury (AKI). Design, setting and participants: A prospective observational study in which we measured uACE2 activity in 105 critically ill patients at risk of AKI. We report AKI stage 2 or 3 at 12 hours of urine collection (AKI12h) and AKI stage 2 or 3 at any time during intensive care unit stay in patients free from any stage of AKI at inclusion (AKIICU). AKI prediction was assessed using area under the receiver-operating characteristics curve (AUROC) and net reclassification indices (NRIs). Main outcome measure: AKI stage 2 or 3 at 12 hours of urine collection. Results: Within 12 hours of inclusion, 32 of 105 patients (30%) had developed AKI12h. Corrected uACE2 activity was significantly higher in patients without AKI12h compared with those with AKI12h (median [interquartile range], 13 [6-24] v 7 [4-10] pmol/min/mL per mmol/L of urine creatinine; P < 0.01). A 10-unit increase in uACE2 was associated with a 28% decrease in AKI12h risk (odds ratio [95% CI], 0.72 [0.46-0.97]). During intensive care unit admission, 39 of 76 patients (51%) developed AKIICU. uACE2 had an AUROC for the prediction of AKI12h of 0.68 (95% CI, 0.57-0.79), and correctly reclassified 28% of patients (positive NRI) to AKI12h. Patients with uACE2 > 8.7 pmol/min/mL per mmol/L of urine creatinine had a significantly lower risk of AKIICU on log-rank analysis (52% v 84%; P < 0.01). Conclusions: Higher uACE2 activity was associated with a decreased risk of AKI stage 2 or 3. Our findings support future evaluations of the role of the non-classical renin-angiotensin system during AKI.

Risk prediction for severe acute kidney injury by integration of urine output, glomerular filtration, and urinary cell cycle arrest biomarkers

BACKGROUND

Frequent assessment of urine output (UO), serum creatinine (sCr) and urinary cell cycle arrest biomarkers (CCAB) may improve acute kidney injury (AKI) prediction.

OBJECTIVE

To study the performance of UO, short term sCr changes and urinary CCAB to predict severe AKI.

METHODS

We measured 6 hours of UO, 6-hourly sCr changes, and urinary CCABs in all critically ill patients with cardiovascular or respiratory failure or early signs of renal stress between February and October 2018. We studied the association of such measurements, and their combination, with the development of AKI Stage 2 or 3 of the Kidney Disease: Improving Global Outcomes (KDIGO) definition at 12 hours. We evaluated predictive performance with logistic regression, area under the receiver operating characteristic (AUROC) curve, and net reclassification indices. We computed an optimal cut-off value for each biomarker.

RESULTS

We assessed 622 patients and, as per the exclusion criteria, we enrolled 105 critically ill patients. After 12 hours of enrolment, AKI occurred in 32 patients (30%). UO, sCr change over 6 hours and CCABs were significantly associated with severe AKI at 12 hours, with all variables achieving an AUROC > 0.7 after adjustment. Combination of any of the two or three variables achieved an AUROC > 0.7 for subsequent severe AKI at 12 hours. The optimal predictive high specificity cut-off values were ≤ 0.4 mL/kg/h for UO, variation of +15 μmol/L over 6 hours in sCr, and ≥ 1.5 (ng/mL)2/1000 for CCABs.

CONCLUSION

In this prospective study, an integrative approach using UO, short term sCr change and/or urinary CCABs showed a satisfactory performance for the prediction of severe AKI development at 12 hours.

Risk prediction for severe acute kidney injury by integration of urine output, glomerular filtration, and urinary cell cycle arrest biomarkers

BACKGROUND: Frequent assessment of urine output (UO), serum creatinine (sCr) and urinary cell cycle arrest biomarkers (CCAB) may improve acute kidney injury (AKI) prediction. OBJECTIVE: To study the performance of UO, short term sCr changes and urinary CCAB to predict severe AKI. METHODS: We measured 6 hours of UO, 6-hourly sCr changes, and urinary CCABs in all critically ill patients with cardiovascular or respiratory failure or early signs of renal stress between February and October 2018. We studied the association of such measurements, and their combination, with the development of AKI Stage 2 or 3 of the Kidney Disease: Improving Global Outcomes (KDIGO) definition at 12 hours. We evaluated predictive performance with logistic regression, area under the receiver operating characteristic (AUROC) curve, and net reclassification indices. We computed an optimal cut-off value for each biomarker. RESULTS: We assessed 622 patients and, as per the exclusion criteria, we enrolled 105 critically ill patients. After 12 hours of enrolment, AKI occurred in 32 patients (30%). UO, sCr change over 6 hours and CCABs were significantly associated with severe AKI at 12 hours, with all variables achieving an AUROC > 0.7 after adjustment. Combination of any of the two or three variables achieved an AUROC > 0.7 for subsequent severe AKI at 12 hours. The optimal predictive high specificity cut-off values were ≤ 0.4 mL/kg/h for UO, variation of +15 μmol/L over 6 hours in sCr, and ≥ 1.5 (ng/mL)2/1000 for CCABs. CONCLUSION: In this prospective study, an integrative approach using UO, short term sCr change and/or urinary CCABs showed a satisfactory performance for the prediction of severe AKI development at 12 hours.

Circulating SPINT1 is a biomarker of pregnancies with poor placental function and fetal growth restriction

Placental insufficiency can cause fetal growth restriction and stillbirth. There are no reliable screening tests for placental insufficiency, especially near-term gestation when the risk of stillbirth rises. Here we show a strong association between low circulating plasma serine peptidase inhibitor Kunitz type-1 (SPINT1) concentrations at 36 weeks' gestation and low birthweight, an indicator of placental insufficiency. We generate a 4-tier risk model based on SPINT1 concentrations, where the highest risk tier has approximately a 2-5 fold risk of birthing neonates with birthweights under the 3^rd, 5^th, 10^th and 20^th centiles, whereas the lowest risk tier has a 0-0.3 fold risk. Low SPINT1 is associated with antenatal ultrasound and neonatal anthropomorphic indicators of placental insufficiency. We validate the association between low circulating SPINT1 and placental insufficiency in two other cohorts. Low circulating SPINT1 is a marker of placental insufficiency and may identify pregnancies with an elevated risk of stillbirth.

A longitudinal study of thyroid autoantibodies in pregnancy: the importance of test timing

OBJECTIVE

Thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TGAb) are frequently measured to investigate thyroid dysfunction in pregnancy. Despite the recognized fall of these autoantibodies in pregnancy, there is limited guidance on the timing of such testing. We assessed optimal test timing of TPOAb/TGAb for the detection of Hashimoto's thyroiditis and post-partum thyroid dysfunction (PPTD).

DESIGN

Prospective longitudinal study with recruitment in Trimester 1.

PATIENTS

Healthy women ≤13 weeks' gestation from Mercy Hospital for Women, a tertiary obstetric hospital in Melbourne.

MEASUREMENTS

Serum TPOAb, TGAb, TSH and fT4 were measured at Trimester 1 (T1), Trimester 2(T2), Trimester 3(T3) and postpartum (PP) in each participant. Post-partum thyroid dysfunction (PPTD) was defined if TSH deviated from the assay's nonpregnant reference interval. Longitudinal random-effect logistic regression was used to investigate the association between time and positive/negative thyroid autoantibody status.

RESULTS

Samples from 140 women at T1 (12·0: 10·3-13·0) (median: IQR weeks' gestation); 95 at T2 (24·3: 23·0-25·9), 79 at T3 (35·9: 34·8-36·7) and 83 at PP (12·4: 10·8-14·6 weeks post-partum) were attained. At T1, 13 (9%) and 15 (11%) women had positive TPOAb and TGAb, respectively. The odds of having a positive TPOAb were 96% lower at T2 [OR = 0·04 (95% CI: 0·02-0·8; P = 0·03)] and 97% lower at T3 [OR = 0·03 (95% CI: 0·001-0·6; P = 0·02)] than at T1. Similarly, the odds of having a positive TGAb were 99·4% lower [OR = 0·006 (95% CI: 0-0·3; P = 0·01)] at T2, and 99·5% lower [OR = 0·005 (95% CI: 0-0·4; P = 0·02)] at T3 than at T1. The ROC analysis diagnostic ORs for a positive TPOAb and/or TGAb to predict PPTD were 7·8 (95% CI: 2·2-27·6), 1·2 (95% CI: 0-8·9), 2·0 (95% CI: 0-16·8), and 12·2 (95% CI: 3·3-44·9) at T1, T2, T3 and post-partum, respectively.

CONCLUSIONS

A significant proportion of pregnant women lose their thyroid autoantibody positivity after T1. The gestation-dependent loss of TPOAb/TGAb positivity and reduction in diagnostic accuracy for predicting PPTD limits the value of testing at T2 and T3.

Longitudinal assessment of thyroid function in pregnancy

Background

Trimester-specific reference intervals (RIs) for thyroid function tests are lacking for Beckman Dxl 800 analysers. We aimed to establish RIs for thyroid stimulating hormone (TSH), free thyroxine (fT4) and to track intraindividual changes in thyroid function throughout pregnancy.

Methods

One hundred and thirty healthy women without antithyroid peroxidase antibodies were followed longitudinally. Thyroid function was determined at trimester-1 (T1): 9–13 weeks; trimester-2 (T2): 22–26 weeks; trimester-3 (T3): 35–39 weeks and postpartum (PP): 8–12 weeks. A subgroup ( n = 47) was used to track intraindividual changes using PP as non-pregnant state (baseline).

Results

For trimesters 1–3, TSH (median (2.5th, 5th, 95th and 97.5th percentile)) was 0.77 (0.03, 0.05, 2.33, 3.05), 1.17 (0.42, 0.47, 2.71, 3.36) and 1.35 (0.34, 0.42, 2.65, 2.83) mIU/L, respectively. Free T4 (mean (95%CI)) was 10.7 (5.9–15.5), 8.1 (4.9–11.3), 7.8 (4.5–11.0) pmol/L, respectively. In T2 and T3, 36% and 41% of the fT4 values, respectively, fell below the non-pregnancy lower normal limit. In the subgroup assessed for longitudinal changes, of the women with baseline TSH ⩽ median, 71–75% remained at or below the corresponding median for trimesters 1–3. Of the women with baseline fT4 ⩽ median, 69–81% also remained at or below the corresponding median for trimesters 1–3. High correlation was observed at different trimesters and baseline for TSH (Spearman’s r: 0.593–0.846, P < 0.001) and for fT4 ( r: 0.480–0.739, P < 0.001).

Conclusions

Use of trimester-specific RIs would prevent misclassification of thyroid function during pregnancy. In the majority of women, TSH and fT4 tracked on the same side of the median distribution, from a non-pregnant baseline, throughout pregnancy.

[Volvulus of the mobile spleen. Conservative laparoscopic treatment]

BACKGROUND

Volvulus of the mobile spleen is a rare condition generally manifested by acute sudden onset abdominal pain localized in the left flank. Ultrasound or computed tomographic imaging generally provides the diagnosis.

CASE REPORT

An 18-year-old patient was hospitalized for acute pain of the left flank that had begun 48 hours earlier. The abdominal scan visualized a volvulus of a mobile spleen. Laparoscopic distortion was successful, allowing normal recoloration of the spleen.

DISCUSSION

Rapid intervention is crucial for conservative treatment. Laparoscopic treatment allows distortion manoeuvres and splenopexia using a mesh. This is the first reported case of successful conservative laparoscopic treatment of volvulus of a mobile spleen.

[Cystic dystrophy of an aberrant pancreas. Surgery after failure of medical therapy]

BACKGROUND

Cystic dystrophy of aberrant pancreas, characterized by cystic formations in ectopic pancreatic tissue, produces variable signs. Treatment is difficult.

CASE REPORT

Our patient presented signs of acute pancreatitis and angiocholitis due to cystic dystrophy of an aberrant pancreas situated in the duodenal wall associated with chronic alcoholic pancreatitis. Prolonged medical treatment was unsuccessful. Duodenopancreatectomy with preservation of the tail led to complete regression of the clinical signs.

DISCUSSION

Signs of cystic dystrophy of an aberrant pancreas vary greatly. Diagnosis is generally established on the basis of echoendoscopic findings. After failure of medical treatment, duodenopancreatectomy with preservation of the tail could be the most appropriate surgical treatment, hypothesizing that the disorders result from obstruction of the Wirsung and the lower main bile ducts.