Oxidative nucleic acid damage as a biomarker for preeclampsia.

Recent studies have reported that nucleic acid oxidation is elevated in preeclampsia. Furthermore, it is known that products of nucleic acid oxidation are eventually removed through the urine. The aim of this study was to check whether urine can be used as a non-invasive specimen to analyse nucleic acid oxidation in preeclampsia. We carried out a case-control study by enrolling preeclamptic pregnant (n = 31) and normotensive pregnant (n = 31) women. Urine samples from the study participants were collected and the levels of oxidised guanine species (a common product of nucleic acid oxidation) were determined by ELISA method. The urinary levels of oxidised guanine species were significantly higher in the preeclamptic pregnant group compared to the normotensive pregnant group (p = 0.001). The results were also analysed after stratifying the preeclamptic group in terms of severity and gestational age of onset. A significant difference was observed in both mild (p = 0.005) and severe preeclampsia (p = 0.01). However, a significant difference was observed only in the late onset (p = 0.001) and not in the early onset preeclampsia (p = 0.56). The results of this study show that oxidised guanine level is elevated in the urine of preeclamptic pregnant women. IMPACT STATEMENTWhat is already known on this subject? Nucleic acid oxidation is elevated in preeclampsia. However, the utility of urine (a non-invasive specimen) to analyse nucleic acid oxidation is not known.What do the results of this study add? This study shows that the levels of oxidised guanine (a marker of nucleic acid oxidation) are elevated in the urine of preeclamptic women.What are the implications of these findings for clinical practice and/or further research? Urinary levels of oxidised guanine may be developed as a non-invasive biomarker for preeclampsia.

Urinary protein carbonyl levels and its correlation with protein misfolding in preeclampsia.

OBJECTIVE: To evaluate the association of protein carbonylation with preeclampsia and its correlation with urinary protein misfolding. METHOD: Protein carbonyl and misfolded protein levels were measured in the midstream urine sample (58 preeclamptic and 44 normotensive pregnancy) by ELISA and Congo Red Dot assay respectively. RESULTS: Significant difference was observed in the levels of protein carbonyls (P = 0.002) and misfolded proteins (P = 0.001). Correlation between protein carbonyl and misfolded proteins levels was significant but weak (r = 0.3; P = 0.018). CONCLUSION: Urinary protein carbonyl level is elevated in preeclampsia but plays a minor role in proteins misfolding.

Urinary congophilia in preeclampsia: Experience from a rural tertiary-care hospital in India.

OBJECTIVES: To evaluate the presence of urinary congophilia amongIndian patients with preeclampsia. STUDY DESIGN: A prospective case control study in which congophilia of urine samples from preeclamptic pregnant women (n = 62) and normotensive pregnant women (n = 65) was compared by using Congo Red Dot Blot assay. MAIN OUTCOME MEASURES: Presence of urinary congophilia. RESULTS: Mean percentage of Congo Red Retention was 37.9 ±â€¯4.1 in the normotensive pregnant group and 77.9 ±â€¯11.5 in the preeclamptic pregnant group (P < .001). The mean percentage of Congo Red Retention in both early-onset (70.5 ±â€¯9.0) and late-onset (82.7 ±â€¯10.3) groups were significantly higher than in normotensive controls (P < .001). The mean percentage of Congo Red Retention in mild (61.2 ±â€¯3.2) and severe (82.4 ±â€¯8.4) types of preeclampsia were also as significantly higher than in normotensive controls (P < .001). The mean percentage of Congo Red Retention in preeclampsia superimposed by eclampsia (89.4 ±â€¯2.0) and preeclampsia complicated by intrauterine growth restriction and intrauterine death (74.6 ±â€¯5.8) were significantly higher than in normotensive controls (P < .001). CONCLUSIONS: The results of this study confirms the presence of urinary congophilia in Indian pregnant women with preeclampsia. Furthermore, our study shows that urinary congophilia is not affected by clinical variables like gestational age of onset, severity, superimposition by eclampsia and complication by intrauterine growth restriction and intrauterine death. Urinary congophilia can be used to differentially identify preeclamptic pregnant women from normotensive pregnant women.