Serum cystatin C levels in preterm newborns in our setting: Correlation with serum creatinine and preterm pathologies

The progression of serum cystatin C concentrations within the first month of life after preterm birth-a worldwide systematic review

Multiple single-center studies have examined the progression of kidney function biomarkers such as serum cystatin C (Cys C) in the first 30 days of life (DOL) after preterm birth, but from different ethnicities and in different gestational ages (GA), without a functional summary available. We performed a systematic literature review within PubMed, Google Scholar, and Scopus, with additional use of the snowballing method to find studies including data on serum Cys C concentrations in the first 30 DOL. We identified 15 papers that met criteria, published from 2000 to 2019, from 10 countries across 4 continents, in 1468 babies born preterm. Cys C was superior to creatinine in 11/13 studies, and equal in 2/13. For infants born at 24-28 weeks GA, the DOL1 Cys C concentrations ranged from 1.44 to 1.90 mg/L, from 1.20 to 1.77 on DOL3, and from 1.36 to 2.02 between DOL 4 and 30. For infants born at 29-33 weeks GA, the DOL1 Cys C values ranged from 1.41 to 1.96 mg/L, from 1.28 to 1.70 on DOL3, and 1.51 to 1.87 between DOL 4 and 30. For preterm infants born after 34 weeks GA, the DOL1 Cys C values ranged from 1.22 to 1.96 mg/L, from 1.24 to 1.85 on DOL3, and 1.22 to 1.82 between DOL 4 and 30. This systematic review provides generalizable worldwide reference data on Cys C that could be used to estimate progression or resolution of abnormal kidney function in the first months after preterm birth, stratified by GA.

Cystatin C: A more reliable biomarker of renal function in young infants? A longitudinal cohort study

Aim

We carried out a longitudinal cohort study to measure serial CysC (Cystatin C) in a cohort of neonates born preterm until the age of 2 years. We hypothesised that CysC levels are independent of body weight and would not vary with gestational age.

Methods

This prospective cohort study was conducted from August 2014 until October 2016, and follow‐up was completed in October 2018. Preterm infants at less than 28 weeks of gestation (extremely preterm infants) were recruited and followed up until the age of 24 months. Blood samples for measurement of CysC were collected at regular intervals.

Results

We recruited 58 preterm neonates with mean gestation was 26.2 (1.5) weeks, and a mean birth weight was 917 (140) g. One‐way analysis of variance (ANOVA) did not show any significant difference in CysC levels between 28, 32 and 37 weeks' gestation (P = .09) despite a significant increase in body weight (P < .001). The mean CysC level was higher in the neonatal period and subsequently plateaued by 24 months.

Conclusion

Serum CysC level is independent of body weight and not influenced by postnatal age nor by gender.

Vertical transmission and kidney damage in newborns whose mothers had coronavirus disease 2019 during pregnancy

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COVID-19 caused by SARS-CoV-2 has become a global pandemic

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Clinical characteristics assessed for 22 neonates born to mothers with COVID-19 during pregnancy

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COVID-19 in the third trimester of pregnancy could cause fetal kidney developmental injury

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There is the possibility of maternal-fetal transmission of SARS-CoV-2

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Study provides a theoretical basis for early diagnosis of developmental toxicity in neonates from mothers with COVID-19

Objectives

Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic. However, the hazard to newborns in pregnancy remains controversial. The aim of this study was to investigate the vertical transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from mother to child and developmental toxicity in the fetus.

Methods

All clinical information was recorded on 22 neonates born to mothers with confirmed COVID-19 pneumonia in Tongji Hospital.

Results

The average birth weight of the 22 newborns (16 males and 6 females) was 2980 g, and the mean gestational week was 37W+3. The birth weight of three babies was <2500 g, and the gestational week of all three low-birth-weight neonates was less than 36W. Three newborns had minor lesions of infection in the lungs as shown by computed tomography (CT) scans. Furthermore, three newborns had elevated SARS-CoV-2-related immunoglobin M (IgM) antibodies, and 11 newborns (52.4%) had positive immunoglobin G (IgG) antibodies. Notably, both cystatin C and β2-microglobulin were increased in all newborns. Five of the 21 tested newborns had leukocytosis, and 11 had increased neutrophil levels. In addition, the aspartate aminotransferase of 18 newborns and the γ-glutamyl transpeptidase of 19 newborns were increased. Total bilirubin was elevated in all newborns and serum albumin was reduced in 20 of 22 newborns.

Conclusions

This study was the first to discover that COVID-19 infection in the third trimester of pregnancy could cause fetal kidney developmental injury, as indicated by increased cystatin C and β2-microglobulin in all neonates. Furthermore, there is the possibility of maternal-fetal transmission of SARS-CoV-2.

Reference values for serum cystatin C in very low-birthweight infants: From two centres of China

AIM

To determine the level of cystatin C (Cys-C) values in preterm babies for the purpose of becoming a good endogenous marker of renal function.

METHODS

A total of 366 very low-birthweight infants (including 70 extremely low-birthweight babies) with gestational age <37 weeks born in two centres were studied.

RESULTS

In very low-birthweight infants, the mean level of Cys-C was 1.96 ± 0.44 mg/L in blood samples taken on day 1, 1.78 ± 0.49 mg/L on day 7 and 1.71 ± 0.47 mg/L on day 28. In extremely low-birthweight infants, the mean level of Cys-C was 2.00 ± 0.49 mg/L on day 1, 1.63 ± 0.38 mg/L on day 7 and 1.62 ± 0.55 mg/L on day 28, respectively. Compared to serum creatinine and blood urea nitrogen, Cys-C level was independent of birthweight and gestational age.

CONCLUSION

Cys-C is regarded as an alternative for assessing renal function in very low-birthweight infants, but its advantages over serum creatinine and blood urea nitrogen has not been fully proved yet. Hence, larger sample study is still necessary.