Maternal serum soluble CD30 is increased in pregnancies complicated with acute pyelonephritis

A biomarker for bacteremia in pregnant women with acute pyelonephritis: soluble suppressor of tumorigenicity 2 or sST2

Objective: Sepsis is a leading cause of maternal death, and its diagnosis during the golden hour is critical to improve survival. Acute pyelonephritis in pregnancy is a risk factor for obstetrical and medical complications, and it is a major cause of sepsis, as bacteremia complicates 15-20% of pyelonephritis episodes in pregnancy. The diagnosis of bacteremia currently relies on blood cultures, whereas a rapid test could allow timely management and improved outcomes. Soluble suppression of tumorigenicity 2 (sST2) was previously proposed as a biomarker for sepsis in non-pregnant adults and children. This study was designed to determine whether maternal plasma concentrations of sST2 in pregnant patients with pyelonephritis can help to identify those at risk for bacteremia.Study design: This cross-sectional study included women with normal pregnancy (n = 131) and pregnant women with acute pyelonephritis (n = 36). Acute pyelonephritis was diagnosed based on a combination of clinical findings and a positive urine culture. Patients were further classified according to the results of blood cultures into those with and without bacteremia. Plasma concentrations of sST2 were determined by a sensitive immunoassay. Non-parametric statistics were used for analysis.Results: The maternal plasma sST2 concentration increased with gestational age in normal pregnancies. Pregnant patients with acute pyelonephritis had a higher median (interquartile range) plasma sST2 concentration than those with a normal pregnancy [85 (47-239) ng/mL vs. 31 (14-52) ng/mL, p < .001]. Among patients with pyelonephritis, those with a positive blood culture had a median plasma concentration of sST2 higher than that of patients with a negative blood culture [258 (IQR: 75-305) ng/mL vs. 83 (IQR: 46-153) ng/mL; p = .03]. An elevated plasma concentration of sST2 ≥ 215 ng/mL had a sensitivity of 73% and a specificity of 95% (area under the receiver operating characteristic curve, 0.74; p = .003) with a positive likelihood ratio of 13.8 and a negative likelihood ratio of 0.3 for the identification of patients who had a positive blood culture.Conclusion: sST2 is a candidate biomarker to identify bacteremia in pregnant women with pyelonephritis. Rapid identification of these patients may optimize patient care.

Peritransplant Soluble CD30 as a Risk Factor for Slow Kidney Allograft Function, Early Acute Rejection, Worse Long-Term Allograft Function, and Patients' Survival

BACKGROUND

We aimed to determine whether serum soluble CD30 (sCD30) could identify recipients at high risk for unfavorable early and late kidney transplant outcomes.

METHODS

Serum sCD30 was measured on the day of kidney transplantation and on the 4th day posttransplant. We assessed the value of these measurements in predicting delayed graft function, slow graft function (SGF), acute rejection (AR), pyelonephritis, decline of allograft function after 6 months, and graft and patient survival during 5 years of follow-up in 45 recipients.

RESULTS

We found the association between low pretransplant serum levels of sCD30 and SGF. The absence of significant decrease of sCD30 on the 4th day posttransplant was characteristic for SGF, early AR (the 8th day-6 months), late AR (>6 months), and early pyelonephritis (the 8th day-2 months). Lower pretransplant and posttransplant sCD30 predicted worse allograft function at 6 months and 2 years, respectively. Higher pretransplant sCD30 was associated with higher frequency of early AR, and worse patients' survival, but only in the recipients of deceased-donor graft. Pretransplant sCD30 also allowed to differentiate patients with early pyelonephritis and early AR.

CONCLUSIONS

Peritransplant sCD30 is useful in identifying patients at risk for unfavorable early and late transplant outcomes.

Serum sCD30: A promising biomarker for predicting the risk of bacterial infection after kidney transplantation

BACKGROUND

The transmembrane glycoprotein CD30 contributes to regulate the balance between Th₁ and Th₂ responses. Previous studies have reported conflicting results on the utility of its soluble form (sCD30) to predict post-transplant infection.

METHODS

Serum sCD30 was measured by a commercial ELISA assay at baseline and post-transplant months 1, 3, and 6 in 100 kidney transplant (KT) recipients (279 monitoring points). The impact of sCD30 levels on the incidence of overall, bacterial and opportunistic infection during the first 12 months after transplantation was assessed by Cox regression.

RESULTS

There were no differences in serum sCD30 according to the occurrence of overall or opportunistic infection. However, sCD30 levels were higher in patients with bacterial infection compared to those without at baseline (P=.038) and months 1 (P<.0001), 3 (P=.043), and 6 after transplantation (P=.006). Patients with baseline sCD30 levels ≥13.5 ng/mL had lower 12-month bacterial infection-free survival (35.0% vs 80.0%; P<.0001). After adjusting for potential confounders, baseline sCD30 levels ≥13.5 ng/mL remained as an independent risk factor for bacterial infection (adjusted hazard ratio [aHR]: 4.65; 95% confidence interval [CI]: 2.05-10.53; <.001). Analogously, sCD30 levels ≥6.0 ng/mL at month 1 acted as a risk factor for subsequent bacterial infection (aHR: 5.29; 95% CI: 1.11-25.14; P=.036).

CONCLUSION

Higher serum sCD30 levels were associated with an increased risk of bacterial infection after KT. We hypothesize that this biomarker reflects a Th₂ -polarized T-cell response, which exerts a detrimental effect on the immunity against bacterial pathogens.

Intra-amniotic administration of lipopolysaccharide induces spontaneous preterm labor and birth in the absence of a body temperature change

OBJECTIVE

Intra-amniotic infection is associated with spontaneous preterm labor. In most cases, the infection is subclinical and bacteria are detected in the amniotic cavity rather than in the chorioamniotic membranes. The aims of this study were to establish a model of intra-amniotic lipopolysaccharide (LPS)-induced preterm labor/birth that resembles the subclinical syndrome and to compare this model to two established models of LPS-induced preterm labor/birth.

METHODS

Pregnant B6 mice received an intra-amniotic, intra-uterine, or intra-peritoneal injection of LPS (100 ng/amniotic sac, 15 μg/25 μL, and 15 μg/200 μL respectively) or PBS (control). Following injection, body temperature (every two hours for a 12-h period), gestational age, and the rate of preterm labor/birth were recorded.

RESULTS

An intra-amniotic injection of LPS resulted in preterm labor/birth [LPS 80 ± 24.79% (8/10) versus PBS 0% (0/8); p = 0.001] without causing maternal hypothermia. Intra-peritoneal [LPS 100% (8/8) versus PBS 0% (0/8); p < 0.001)] and intra-uterine [LPS 100% (8/8) versus PBS 28.57 ± 33.47% (2/7); p =0 .007] injections of LPS induced preterm labor/birth; yet, maternal hypothermia was observed.

CONCLUSION

Intra-amniotic injection of LPS induces preterm labor/birth in the absence of a body temperature change, which resembles the subclinical syndrome.

The peripheral whole-blood transcriptome of acute pyelonephritis in human pregnancya

OBJECTIVE

Human pregnancy is characterized by activation of the innate immune response and suppression of adaptive immunity. The former is thought to provide protection against infection for the mother, and the latter, tolerance against paternal antigens expressed in fetal cells. Acute pyelonephritis is associated with an increased risk of acute respiratory distress syndrome and sepsis in pregnant (vs. nonpregnant) women. The objective of this study was to describe the gene expression profile (transcriptome) of maternal whole blood in acute pyelonephritis.

METHOD

A case-control study was conducted to include pregnant women with acute pyelonephritis (n=15) and women with a normal pregnancy (n=34). Affymetrix HG-U133 Plus 2.0 arrays (Affymetrix, Santa Clara, CA, USA) were used for gene expression profiling. A linear model was used to test the association between the presence of pyelonephritis and gene expression levels while controlling for white blood cell count and gestational age. A fold change of 1.5 was considered significant at a false discovery rate of 0.1. A subset of differentially expressed genes (n=56) was tested with real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) (cases, n=19; controls, n=59). Gene ontology and pathway analyses were applied.

RESULTS

A total of 983 genes were differentially expressed in acute pyelonephritis: 457 were upregulated and 526 were downregulated. Significant enrichment of 300 biological processes and 63 molecular functions was found in pyelonephritis. Significantly impacted pathways in pyelonephritis included (a) cytokine-cytokine receptor interaction, (b) T-cell receptor signaling, (c) Jak-STAT signaling, and (d) complement and coagulation cascades. Of 56 genes tested by qRT-PCR, 48 (85.7%) had confirmation of differential expression.

CONCLUSION

This is the first study of the transcriptomic signature of whole blood in pregnant women with acute pyelonephritis. Acute infection during pregnancy is associated with the increased expression of genes involved in innate immunity and the decreased expression of genes involved in lymphocyte function.

Soluble TRAIL in normal pregnancy and acute pyelonephritis: a potential explanation for the susceptibility of pregnant women to microbial products and infection

OBJECTIVE

Pregnancy is characterized by activation of the innate immune response demonstrated by phenotypic and metabolic changes in granulocytes and monocytes. This state of activation has been implicated in the pathophysiology of multiorgan dysfunction of pregnant women with acute viral or bacterial infection. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is one of the mediators responsible for neutrophil apoptosis. Gene deletion of TRAIL results in delayed neutrophil apoptosis and resolution of inflammation after the administration of bacterial endotoxin. The aim of this study was to determine whether maternal plasma concentrations of the soluble form of TRAIL (sTRAIL) differ in women with uncomplicated pregnancy and those with acute pyelonephritis.

METHOD

A cross-sectional study was conducted to include women in the following groups: (1) non-pregnant (n = 23); (2) uncomplicated pregnancies (n = 93) and (3) pregnancies with acute pyelonephritis (n = 23). Plasma concentrations of sTRAIL were determined by enzyme-linked immunoassay.

RESULTS

(1) Women with uncomplicated pregnancies had a lower mean plasma sTRAIL concentration (pg/mL) than non-pregnant women (31.5 ± 10.1 versus 53.3 ± 12.5; p < 0.001); (2) plasma sTRAIL concentrations did not change as a function of gestational age (Pearson correlation = -0.1; p = 0.4); (3) the mean plasma sTRAIL concentration (pg/mL) was significantly lower in pregnant women with acute pyelonephritis than in those with uncomplicated pregnancies (20.5 ± 6.6 versus 31.5 ± 10.1; p < 0.001) and (4) among patients with acute pyelonephritis, patients with bacteremia had a significantly lower mean plasma concentration of sTRAIL (pg/mL) than those without bacteremia (15.1 ± 4.8 versus 24.7 ± 4.6; p < 0.001).

CONCLUSION

Women with uncomplicated pregnancies are associated with a significantly lower mean maternal plasma concentration of sTRAIL than that observed in non-pregnant women. Moreover, a further decrease in plasma sTRAIL concentration was observed in pregnant women with acute pyelonephritis, and this could account, at least in part, for the exaggerated intravascular inflammatory response previously reported in pyelonephritis during pregnancy.

Evaluation of serum levels of sCD30L ligand in patients with ovarian cancer in terms of selected clinico-pathological factors

AIM OF THE STUDY

The CD30L ligand is a membrane-associated glycoprotein expressed by activated CD4(+)Th cells, macrophages, dendritic cells, and B lymphocytes. It binds to the CD30 receptor carried on activated and helper Th cells, inducing the immune response and apoptosis. The aim of this retrospective study was to determine the level of sCD30L in the serum of patients at diagnosis of ovarian cancer and at relapse and to assess the potential association of this ligand with selected clinico-pathologic factors.

MATERIAL AND METHODS

We studied 69 patients with ovarian cancer allocated to two groups: A - ovarian cancer at diagnosis, B - relapse of ovarian cancer and active growth of the tumor.

RESULTS

We found high levels of sCD30L in ovarian cancer patients. Levels at relapse (21.48 ng/ml) were significantly higher than at diagnosis (11.81 ng/ml). Poor response to first-line chemotherapy was accompanied by higher levels of sCD30L and by several other findings: resistance to platinum analogs was common, neoadjuvant chemotherapy was needed, relapse and death during two-year follow-up were frequent.

CONCLUSIONS

Our present study might initially suggest that elevated concentration of sCD30L can be an important finding prognosticating a poor prognosis and is associated with platinum resistant and refractory cases of ovarian cancer. However, studies are needed on larger groups of patients.

Fragment Bb: evidence for activation of the alternative pathway of the complement system in pregnant women with acute pyelonephritis

OBJECTIVE

Pyelonephritis during pregnancy is associated with a more severe course than in the non-pregnant state. This has been attributed to an increased susceptibility of pregnant women to microbial products. The complement system is part of innate immunity and its alternative pathway is activated mainly by microorganisms. The purpose of this study was to determine if activation of the alternative pathway of the complement system (determined by maternal fragment Bb concentrations) occurs in pregnant women with acute pyelonephritis.

METHODS

This cross-sectional study included the following groups: (1) normal pregnant women (n=62) and (2) pregnant women with pyelonephritis (n=38). Maternal plasma fragment Bb concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

(1) Pregnant women with pyelonephritis had a higher median plasma concentration of fragment Bb than those with a normal pregnancy (1.3 μg/ml, IQR: 1.1-1.9 vs. 0.8 μg/ml, IQR: 0.7-0.9; p<0.001); (2) No significant differences were observed in the median maternal plasma concentration of fragment Bb between pregnant women with pyelonephritis who had a positive blood culture and those with a negative blood culture (1.4 μg/ml, IQR: 1.1-3.5 vs. 1.3 μg/ml, IQR: 1.1-1.9; p=0.2).

CONCLUSIONS

Pregnant women with acute pyelonephritis have evidence of activation of the alternative pathway of the complement system, regardless of the presence or absence of a positive blood culture.

Maternal plasma retinol binding protein 4 in acute pyelonephritis during pregnancy

OBJECTIVE

Adipokines have been implicated in metabolic regulation and the immune response thus providing a molecular mechanism for the interaction between these two systems. Retinol binding protein 4 (RBP4) is a novel adipokine that plays a role in the pathophysiology of obesity-induced insulin resistance, as well as in the modulation of inflammation. The aim of this study was to determine whether there are changes in maternal plasma concentrations of RBP4 in pregnant women with acute pyelonephritis.

STUDY DESIGN

This cross-sectional study included pregnant women in the following groups: 1) normal pregnancy (n=80); 2) pyelonephritis (n=39). Maternal plasma RBP4 concentrations were determined by enzyme-linked immunoassays. Non-parametric statistics were used for analyses.

RESULTS

1) The median maternal plasma RBP4 concentration was lower in patients with acute pyelonephritis than in those with a normal pregnancy (3709.6 ng/mL, interquartile range (IQR) 2917.7-5484.2 vs. 9167.6 ng/mL, IQR 7496.1- 10,384.1, P<0.001; 2) the median maternal plasma RBP4 concentration did not differ significantly between patients with acute pyelonephritis who had a positive blood culture and those with a negative culture (3285.3 ng/mL, IQR 2274.1-4741.1 vs. 3922.6 ng/mL, IQR 3126.8-5547.1, respectively, P=0.2); and 3) lower maternal plasma RBP4 concentrations were independently associated with pyelonephritis after adjustment for confounding factors.

CONCLUSIONS

In contrast to what has been reported in preeclampsia, acute pyelonephritis during pregnancy is associated with lower maternal plasma RBP4 concentrations than in normal pregnancy. This finding suggests that the acute maternal inflammatory process associated with pyelonephritis is fundamentally different from that of the chronic systemic inflammatory process suggested in preeclampsia, in which RBP4 concentrations were found to be elevated.

Acute pyelonephritis during pregnancy changes the balance of angiogenic and anti-angiogenic factors in maternal plasma

OBJECTIVE

Angiogenic factors have been implicated in the pathophysiology of sepsis. In experimental models of sepsis (endotoxemia and/or cecal ligation puncture), there is increased expression of vascular endothelial growth factors (VEGF) and the administration of exogenous soluble VEGF receptor (sVEGFR)-1, an antagonist to VEGF, reduces morbidity and mortality. Moreover, a dramatic elevation in sVEGFR-1 has been demonstrated in human sepsis. Although a balance between angiogenic and anti-angiogenic factors is essential for feto-placental development, the changes of angiogenic factors during pregnancy in the context of infection have never been explored. Angiogenic factors also play crucial roles in the pathophysiology of preeclampsia (PE). This study was conducted to determine if maternal plasma concentrations of placental growth factor (PlGF), sVEGFR-2, and soluble endoglin (sEng) change in pregnancies complicated by acute pyelonephritis (AP) compared with normal pregnancy and PE.

STUDY DESIGN

A case-control study was conducted in patients with AP, normal pregnant (NP) women, and patients with PE (n=36 for each group) matched for gestational age. AP was diagnosed in the presence of fever (temperature >or=38 degrees C), clinical signs of infection, and a positive urine culture for microorganisms. Plasma concentrations of PlGF, sVEGFR-2, and sEng were determined by ELISA. The results of plasma sVEGFR-1 concentrations have previously been reported, but were included in this study to provide a complete picture of the angiogenic/anti-angiogenic profiles. Serum concentrations of interleukin (IL)-1beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, interferon (IFN)-gamma, granulocyte macrophage colony stimulating factor, and tumor necrosis factor (TNF) were also determined using high sensitivity multiplexed immunoassays in patients with AP and NP.

RESULTS

AP was associated with a lower median plasma concentration of PlGF and sVEGFR-2 than NP (both p<0.001). There were no significant differences in the median plasma concentrations of sEng and sVEGFR-1 between AP and NP (p=0.7 and 0.5, respectively). In contrast, there was a 5-fold decrease of the median plasma concentration of PlGF, and an 8-10-fold increase of the median plasma concentrations of sVEGFR-1 and sEng in PE compared with those in AP (all p<0.001). No significant difference in the median plasma concentration of sVEGFR-2 was observed between patients with PE and AP (p=0.5). Pregnant women with AP had median plasma concentrations of IL-6, IL-7, IL-8, IL-10, IFN-gamma, and TNF-alpha significantly higher than those in NP women (all p<0.001, except IL-7 p=0.004).

CONCLUSION

AP is associated with changes in the profile of angiogenic and anti-angiogenic factors. Although some of these changes resemble those in PE (decreased PlGF and sVEGFR-2), the magnitude of the changes of PlGF is much higher in PE. We conclude that despite high plasma inflammatory cytokine concentrations, acute systemic inflammation in pregnancy has a different angiogenic/anti-angiogenic profile than that of PE.

Hyperresistinemia - a novel feature in systemic infection during human pregnancy

PROBLEM

Resistin, originally described as an adipokine, has emerged as a potent pro-inflammatory protein associated with both acute and chronic inflammation. Moreover, resistin has been proposed as a powerful marker of sepsis severity, as well as a predictor of survival of critically ill non-pregnant patients. The aim of this study was to determine whether pyelonephritis during pregnancy is associated with changes in maternal plasma resistin concentrations.

METHODS OF STUDY

This cross-sectional study included the following groups: (i) normal pregnant women (n = 85) and (ii) pregnant women with pyelonephritis (n = 40). Maternal plasma resistin concentrations were determined by ELISA. Non-parametric statistics was used for analyses.

RESULTS

(i) The median maternal plasma resistin concentration was higher in patients with pyelonephritis than in those with a normal pregnancy (P < 0.001); (ii) among patients with pyelonephritis, the median maternal resistin concentration did not differ significantly between those with and without a positive blood culture (P = 0.3); (iii) among patients with pyelonephritis who were diagnosed with systemic inflammatory response syndrome (SIRS), those who fulfilled > or =3 criteria for SIRS had a significantly higher median maternal plasma resistin concentration than those who met only two criteria; and (iv) maternal WBC count positively correlated with circulating resistin concentration (r = 0.47, P = 0.02).

CONCLUSION

Hyperresistinemia is a feature of acute pyelonephritis during pregnancy. The results of this study support the role of resistin as an acute-phase protein in the presence of bacterial infection during pregnancy.

Maternal plasma concentration of the pro-inflammatory adipokine pre-B-cell-enhancing factor (PBEF)/visfatin is elevated in pregnant patients with acute pyelonephritis

PROBLEM

Visfatin/pre-B-cell-enhancing factor (PBEF) has been implicated in the regulation of the innate immune system, as well as in glucose metabolism. Specifically, visfatin plays a requisite role in delayed neutrophil apoptosis in patients with sepsis. The aim of this study was to determine whether pyelonephritis during pregnancy is associated with changes in maternal plasma visfatin concentration in normal weight and overweight/obese patients.

METHOD OF STUDY

This cross-sectional study included the following groups: (1) normal pregnant women (n = 200) and (2) pregnant women with pyelonephritis (n = 40). Maternal plasma visfatin concentrations were determined by ELISA. Non-parametric statistics was used for analyses.

RESULTS

(1) The median maternal plasma visfatin concentration was significantly higher in patients with pyelonephritis than in those with a normal pregnancy; (2) among overweight/obese pregnant women, those with pyelonephritis had a significantly higher median plasma visfatin concentration than women with a normal pregnancy; and (3) pyelonephritis was independently associated with higher maternal plasma visfatin concentrations after adjustment for maternal age, pre-gestational body mass index, smoking status, gestational age at sampling, and birthweight.

CONCLUSION

Acute pyelonephritis during pregnancy is associated with a high circulating maternal visfatin concentration. These findings suggest that visfatin/PBEF may play a role in the regulation of the complex and dynamic crosstalk between inflammation and metabolism during pregnancy.

Low circulating maternal adiponectin in patients with pyelonephritis: adiponectin at the crossroads of pregnancy and infection

OBJECTIVE

An emerging theme in modern biology is that adipose tissue can respond to metabolic stress, and to inflammatory stimuli, by regulating the secretion of a complex network of soluble mediators, termed adipokines. Adiponectin, the most prevalent circulating adipokine in human, has profound insulin-sensitizing and anti-inflammatory properties. Indeed, the notion that adiponectin plays an important role in the interactions between the metabolic and the immune systems has been strongly suggested. Thus, the aim of this study was to determine if pyelonephritis during pregnancy is associated with changes in maternal serum adiponectin concentrations.

STUDY DESIGN

This cross-sectional study included women in the following groups: 1) normal pregnant women (n=200); and 2) pregnant women with pyelonephritis (n=50). Maternal plasma adiponectin concentrations were determined by ELISA. Non-parametric statistics were used for analyses.

RESULTS

1) The median maternal plasma adiponectin concentration was lower in patients with pyelonephritis than in those with a normal pregnancy (P<0.001); 2) among pregnant women with a normal weight, patients with pyelonephritis had a lower median plasma adiponectin concentration than those with a normal pregnancy (P<0.001); 3) similarly, among overweight/obese patients, those with pyelonephritis had a lower median plasma adiponectin concentration than those with a normal pregnancy (P<0.001); and 4) the presence of pyelonephritis was independently associated with maternal plasma adiponectin concentrations after adjustment for maternal age, smoking, gestational age at sampling, and pregestational body mass index (BMI).

CONCLUSION

1) The findings that acute pyelonephritis in pregnancy is characterized by low maternal plasma concentrations of adiponectin in both lean and overweight/obese patients are novel and concur with the antiinflammatory properties of adiponectin; and 2) the results of this study support the notion that adiponectin may play a role in the intricate interface between inflammation and metabolism during pregnancy.