A mitochondrial regulator protein, MNRR1, is elevated in the maternal blood of women with preeclampsia

Figures & data

Table 1. Demographics and clinical characteristics of the study population.

	Early controls(n = 25)	Early preeclampsia (n = 40)	p	Late controls (n = 55)	Late preeclampsia (n = 57)	p
Maternal age (y)	24 (20.5–28)	25 (20.3–30.8)	0.4	22 (20–26)	23 (19.5–26)	.8
African American	88% (22)	77.5% (31)	0.3	92.7% (51)	89.5% (51)	.5
Nulliparity	24% (6)	27.5% (11)	0.8	7.3% (4)	42.1% (24)	<.001
Tobacco use	8% (2)	20% (8)	0.2	14.5% (8)	10.5% (6)	.5
Pre-pregnancy BMI (kg/m^2)	27.2 (23.5–35.6)	27.8 (22.7–32.3)^a	0.7	28.3 (23.3–35.5)^b	27.5 (23.7–32.7)^c	.6
GA at venipuncture (weeks)	28.1 (25.8–30.7)	30.7 (27.6–32.7)	0.052	39.1 (38.7–39.3)	37.9 (35.9–39.3)	.002
GA at delivery (weeks)	39.1 (38.8–39.8)	31.3 (28.4–33.4)	<0.001	39.1 (39.0–39.6)	37.9 (36.2–39.4)	<.001
Birth weight (g)	3235 (3162.5–3395)	1297 (848.5–1678.8)	<0.001	3325 (3155–3510)	2705 (2202.5–3132.5)	<.001
Birthweight percentile	41.5 (31.1–54.1)	14.1 (6.9–23.1)	<0.001	44.9 (32.8–59.4)	22 (3.3–38.2)	<.001
Duration of sample storage (years)	13.3 (12.3–13.5)	15.1 (13.9–16.4)	<0.001	13.3 (12.2–13.9)	13.5 (12.5–14.2)	.1

BMI: body mass index; GA: gestational age.

Data are presented as median (interquartile range) or percentage (number of patients).

Mann–Whitney U-tests were used for continuous variables and Chi-square tests for categorical variables.

^a n = 36; ^bn = 53; ^cn = 55.

Table 2. Severity features of pregnant women with early and late preeclampsia.

	Early preeclampsia (n = 40)	Late preeclampsia (n = 57)	p
Severe features	95% (38)	86% (49)	.2
Highest systolic blood pressure (mmHg)	175 (167.3–188)	162 (155–175)	.007
Highest diastolic blood pressure (mmHg)	108 (100–114.5)	103 (95.5–112)	.2
Systolic blood pressure ≥160 or diastolic blood pressure ≥110 mmHg	80% (32)	70.2% (40)	.3
Headache	42.5% (17)	42.1% (24)	.9
Visual disturbances	22.5% (9)	19.3% (11)	.7
Epigastric pain	15% (6)	12.3% (7)	.7
Highest serum AST (IU/L)	41 (26.3–89.8)	28 (21.3–33.8)^Table Footnotea	<.001
Highest serum ALT (IU/L)	28 (21.8–67.8)^b	19 (13.5–25)^c	<.001
Elevated liver enzymes (AST or ALT ≥70 IU/L)	35% (14)	3.6% (2)^Table Footnotea	<.001
Highest serum creatinine (mg/dL)	0.8 (0.6–0.9)^Table Footnoted	0.7 (0.6–0.8)^Table Footnotee	.2
Renal insufficiency (serum creatinine >1.1 mg/dL)	7.7% (3)^Table Footnoted	2% (1)^Table Footnotee	.2
Lowest platelet count (x10^9/L)	175.5 (123.8–218)	199 (147.3–242.5)^Table Footnotea	.1
Thrombocytopenia (platelet count <100 x 10^9/L)	17.5% (7)	10.7% (6)^Table Footnotea	.3
Pulmonary edema	2.5% (1)	1.8% (1)	.8
Placental lesions of maternal vascular malperfusion	72.5% (29)	42.1% (24)	.003

AST: aspartate aminotransferase; ALT: alanine aminotransferase.

Data are presented as median (interquartile range) or percentage (number of patients).

Mann–Whitney U-tests were used for continuous variables and Chi-square tests for categorical variables.

^a n = 56; ^bn = 30; ^cn = 41; ^dn = 39; ^en = 50.

Figure 1. Plasma MNRR1 concentrations in pregnant women with preeclampsia and controls. The median (IQR) plasma concentration of MNRR1 was significantly higher in patients with early [1632 (924–2926) pg/mL vs. 630 (448–4002) pg/mL; p = .03, adjusted p = .026] and late [1833 (1441–5534) pg/mL vs. 910 (526–6178) pg/mL; p = .001, adjusted p = .021] preeclampsia compared to uncomplicated pregnant women. Y-axis data are presented in logarithmic scale.

Figure 2. Plasma MNRR1 concentrations in women with preeclampsia stratified by the presence of placental lesions of maternal vascular malperfusion (MVM) in early and late preeclampsia compared to their respective controls. For early preeclampsia, the patients with MVM lesions in the placenta had the highest median (IQR) plasma concentration of MNRR1 among the three groups [with MVM 2066 (1070–3188) pg/mL vs. without MVM 888 (812–1781) pg/mL, p = .03; and with MVM vs. controls 630 (448–4002) pg/mL, p = .018, adjusted p = .04]. By contrast, in late preeclampsia, patients with and those without MVM lesions in the placenta had a significantly higher median (IQR) plasma MNRR1 concentration than women in the control group [with MVM 1609 (1392–3135) pg/mL vs. controls 910 (526–6178), p = .1, adjusted p = .045; and without MVM 2023 (1578–8936) pg/mL vs. controls, p = .01]. Y-axis data are presented in logarithmic scale.

Data availability statement

All data generated or analyzed during this study are included in this article. Further inquiries can be directed to the corresponding author at [email protected] (Dr. Romero).