Quantitative analyses of cytokine profiles reveal hormone-mediated modulation of cytokine profiles in recurrent spontaneous miscarriage

PURPOSE

Cytokines play important roles in pregnancy complications. Some hormones such as estrogen, progesterone, and dydrogesterone have been shown to alter cytokine profiles. Understanding how cytokine profiles are affected by these hormones is therefore an important step towards immunomodulatory therapies for pregnancy complications. We analyse previously published data on the effects of estrogen, progesterone, and dydrogesterone on cytokine balances in women having recurrent spontaneous miscarriages.

MATERIALS AND METHODS

Levels of eight cytokines (IFN-γ, IL-2, IL-6, IL-10, IL-13, IL-17, IL-23, TNF-α) from n = 22 women presenting unexplained recurrent spontaneous miscarriages were studied. Cytokine values were recorded after in vitro exposure of peripheral blood cells to estrogen, progesterone, and dydrogesterone. We expand on earlier analysis of the dataset by employing different statistical techniques including effect sizes for individual cytokine values, a more powerful statistical test, and adjusting p-values for multiple comparisons. We employ multivariate analysis methods, including to determine the relative magnitude of the effects of the hormone therapies on cytokines. A new statistical method is introduced based on pairwise distances able to accommodate complex relations in cytokine profiles.

RESULTS

We report several statistically significant differences in individual cytokine values between the control group and each hormone treated group, with estrogen affecting the fewest cytokines, and progesterone and dydrogesterone both affecting seven out of eight cytokines. Exposure to estrogen produces no large effects sizes however, while IFN-γ and IL-17 show large effect sizes for both progesterone and dydrogesterone, among other cytokines. Our new method for identifying which collections (i.e. subsets) of cytokines best distinguish contrasting groups identifies IFN-γ, IL-10 and IL-23 as especially noteworthy for both progesterone and dydrogesterone treatments.

CONCLUSIONS

While some statistically significant differences in cytokine levels after exposure to estrogen are found, these have small effect sizes and are unlikely to be clinically relevant. Progesterone and dydrogesterone both induce statistically significant and large effect-size differences in cytokine levels, hence therapy with these two progestogens is more likely to be clinically relevant. Univariate and multivariate methods for identifying cytokine importances provide insight into which groups of cytokines are most affected and in what ways by therapies.

CytokineExplore: An Online Tool for Statistical Analysis of Cytokine Concentration Datasets

PURPOSE

Cytokine data sets are increasing both in the number of different cytokines measured and the number of samples assayed. Further, typically data from different groups may be contrasted, eg, normal vs complication subjects. Many univariate and multivariate statistical techniques exist to study such cytokine datasets, but the ability to implement these techniques may be lacking for some practitioners, or may not be available quickly and conveniently. Here, we introduce CytokineExplore, an online tool for multi-cytokine and multi-group data analysis of user-provided Microsoft Excel data files.

MATERIALS AND METHODS

In order to illustrate the tool features, we use data from intrauterine growth retardation (IUGR), a pregnancy complication, and normal healthy subjects as a control. The dataset contains levels for 10 cytokines, namely: IL-4, IL-6, IL-8, IL-10, IL-12, IL-13, IL-18, IL-23, interferon-gamma (IFN-γ) and tumour necrosis-alpha (TNF-α), obtained from 34 women with IUGR (further divided into 17 symmetric and 17 asymmetric cases) and 24 gestationally age-matched normal controls.

RESULTS

The online tool automatically generates box-plots, histograms, PCA and PLSDA plots, t-tests and Mann-Whitney statistical tests, cytokine importance values for separating two groups, heatmaps for comparing multiple groups, and other functionalities. Figures generated can be directly downloaded for use in presentations or journal articles.

CONCLUSION

The tool facilitates quick and easy numerical exploration and multivariate analysis of cytokine datasets, to aid basic understanding and hypothesis generation.

Effects of Progesterone, Dydrogesterone and Estrogen on the Production of Th1/Th2/Th17 Cytokines by Lymphocytes from Women with Recurrent Spontaneous Miscarriage

Anti-inflammatory Th2 cytokines have been shown to be associated with healthy, successful pregnancy while pro-inflammatory Th1 and Th17 cytokines are associated with pregnancy loss due to recurrent spontaneous miscarriage. This nexus between unexplained recurrent spontaneous miscarriage (uRSM) and maternal inflammatory has led to the possibility of using pregnancy-related hormones to modify the maternal cytokine bias in a manner that is conducive to successful pregnancy. We investigated the ability of progesterone, dydrogesterone and estrogen to modulate cytokine production by peripheral blood lymphocytes from women undergoing uRSM. Peripheral blood mononuclear cells (PBMC) from females with uRSM were stimulated in vitro with phytohemagglutinin (PHA) in the presence and absence of progesterone or dydrogesterone or 17β-estradiol. Culture supernatants were assayed for IFN-α, TNF-γ, IL-2, IL-6, IL-10, IL-13, IL-17A, and IL-23 by ELISA. Progesterone and dydrogesterone significantly down-regulated the secretion of the Th1 cytokines IFN-α and TNF-γ, and the Th17 cytokine IL-17A, and IL-23. Additionally, the secretion of the Th2 cytokine IL-6 was up-regulated. Estrogen, on the other hand, decreased the production of IFN-α and IL-2, increased the production of IL-6 but did not affect IL-17A and IL-23 secretion. Progestogens and estrogen can decrease the production of some Th1/Th17 inflammatory cytokines secreted by lymphocytes from uRSM and upregulate the production of anti-inflammatory cytokines. These data support the notion that progestogens can be used for altering maternal cytokine profiles to manage pregnancy complications.

Multivariate Comparison of Cytokine Profiles for Normal- and Low-Bone-Density Subjects

Osteoporosis is a serious worldwide public health concern. The role of the immune system in the onset of osteoporosis in postmenopausal women is an area of current research. Here we study data from a panel of 10 cytokines obtained from postmenopausal women, with both normal and low bone mineral density (BMD). Normal- and low-BMD groups are compared and contrasted, and further low-BMD participants are sub-classified into osteopenic and osteoporotic based on BMD levels, and compared to each other. Via the use of multivariate statistical tools, we examine contrasting groups in relation to: (a) the presence of subgroups/clusters; (b) whether groups have statistically different multivariate distributions; (c) how strongly groups differ (if at all), which relates to the practical/clinical significant of any differences; and (d) which cytokines contribute most to any differences between groups. We find that the normal- vs. low-BMD groups are markedly different (p-value = 0.00013), with IL-23, IL-12, TNF-α, IL-4 and IL-6 being the most important differentiating cytokines. No significant difference between the osteopenic and osteoporotic groups is found (p-value = 0.81). These findings may aid the development of cytokine therapies for osteoporosis, and suggest the use of certain cytokine profiles as biomarkers for osteoporosis risk factors, and ways to quantify the progress of treatment therapies.

Multivariate analysis of cytokine profiles in pregnancy complications

PROBLEM

The immunoregulation to tolerate the semiallogeneic fetus during pregnancy includes a harmonious dynamic balance between anti- and pro-inflammatory cytokines. Several earlier studies reported significantly different levels and/or ratios of several cytokines in complicated pregnancy as compared to normal pregnancy. However, as cytokines operate in networks with potentially complex interactions, it is also interesting to compare groups with multi-cytokine data sets, with multivariate analysis. Such analysis will further examine how great the differences are, and which cytokines are more different than others.

METHODS

Various multivariate statistical tools, such as Cramer test, classification and regression trees, partial least squares regression figures, 2-dimensional Kolmogorov-Smirmov test, principal component analysis and gap statistic, were used to compare cytokine data of normal vs anomalous groups of different pregnancy complications.

RESULTS

Multivariate analysis assisted in examining if the groups were different, how strongly they differed, in what ways they differed and further reported evidence for subgroups in 1 group (pregnancy-induced hypertension), possibly indicating multiple causes for the complication.

CONCLUSION

This work contributes to a better understanding of cytokines interaction and may have important implications on targeting cytokine balance modulation or design of future medications or interventions that best direct management or prevention from an immunological approach.

FRAX- vs. T-score-based intervention thresholds for osteoporosis

Many current guidelines for the assessment of osteoporosis, including those in Kuwait, initiate fracture risk assessment in men and women using BMD T-score thresholds. We compared the Kuwaiti guidelines with FRAX-based age-dependent intervention thresholds equivalent to that in women with a prior fragility fracture. FRAX-based intervention thresholds identified women at higher fracture probability than fixed T-score thresholds, particularly in the elderly.

PURPOSE

A FRAX® model been recently calibrated for Kuwait, but guidance is needed on how to utilise fracture probabilities in the assessment and treatment of patients.

METHODS

We compared age-specific fracture probabilities, equivalent to women with no clinical risk factors and a prior fragility fracture (without BMD), with the age-specific fracture probabilities associated with femoral neck T-scores of -2.5 and -1.5 SD, in line with current guidelines in Kuwait. Upper and lower assessment thresholds for BMD testing were additionally explored using FRAX.

RESULTS

When a BMD T-score of -2.5 SD was used as an intervention threshold, FRAX probabilities of a major osteoporotic fracture in women aged 50 years were approximately twofold higher than those in women of the same age but with an average BMD. The increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 83 years or more, a T-score of -2.5 SD was associated with a lower probability of fracture than that of the age-matched general population with no clinical risk factors. The same phenomenon was observed from the age of 66 years at a T-score of -1.5 SD. A FRAX-based intervention threshold, defined as the 10-year probability of a major osteoporotic fracture in a woman of average BMI with a previous fracture, rose with age from 4.3% at the age of 50 years to 23%, at the age of 90 years, and identified women at increased risk at all ages. Qualitatively comparable findings were observed in the case of hip fracture probability and in men.

CONCLUSION

Intervention thresholds based on BMD alone do not optimally target women at higher fracture risk than those on age-matched individuals without clinical risk factors, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a 'fracture threshold' consistently target women at higher fracture risk, irrespective of age.

Pro-inflammatory and anti-inflammatory cytokine profiles in fetal growth restriction

The purpose of this investigation was to measure cytokine production by maternal peripheral blood lymphocytes from women with intrauterine growth restriction (IUGR) and from healthy pregnant women, and to investigate the relationship between cytokine profiles and IUGR. Thirty-six women with IUGR and 22 control healthy pregnant women with normal fetal growth were studied. Levels of pro-inflammatory cytokines (IFNy, TNFa, IL-8, IL-12, IL-18, IL-23) and anti-inflammatory cytokines (IL-4, IL- 10, IL-13) produced by mitogen-stimulated peripheral blood mononuclear cells were measured by ELISA. Levels of the anti-inflammatory cytokine IL-4 were higher in normal pregnancy compared to IUGR, indicating an anti-inflammatory bias. Levels of the pro-inflammatory cytokines IL-6, TNFα, and IL-12 were significantly higher and levels of the anti-inflammatory cytokine IL- 10 lower in IUGR with placental insufficiency than in IUGR without placental insufficiency, suggesting a stronger pro-inflammatory bias in IUGR with placental insufficiency. Ratios of pro- to anti-inflammatory cytokines suggest a dominance of pro-inflammatory cytokines. The authors conclude that an increased pro-inflammatory cytokine bias is observed in IUGR compared to normal pregnancy, and an increased pro-inflammatory cytokine dominance is seen in IUGR with placental insufficiency compared to IUGR without placental insufficiency.

Association between levels of vitamin D and inflammatory markers in healthy women

Background

No one can deny that the biological importance of vitamin D is much beyond its classical role in bone metabolism. Several recent publications have highlighted its potential role in the functioning of the immune system. The overall objective of this study was to look into possible correlations between levels of vitamin D and inflammatory markers in sera of healthy adult women. These markers included proinflammatory cytokines (interleukin [IL]-1β, IL-6, IL-8, IL-17, interferon [IFN]-γ, and tumor necrosis factor [TNF]-α), anti-inflammatory cytokines (IL-4, IL-10, and IL-13), as well as C-reactive protein (CRP) as a general indicator of inflammation.

Methods

Venous blood samples were collected from 118 healthy adult women and serum levels of vitamin D, CRP, proinflammatory cytokines (IL-1β, IL-6, IL-8, IL-17, IFN-γ, and TNF-α), and anti-inflammatory cytokines (IL-4, IL-10, and IL-13) were measured.

Results

There were no significant direct correlations between serum levels of vitamin D and any of the inflammatory markers measured. However, subjects with deficient levels of vitamin D and high CRP produced significantly higher levels of the proinflammatory cytokines (TNF-α and IL-8) as compared to subjects with low CRP levels with nondeficient and deficient levels of vitamin D. Further, the anti-inflammatory/proinflammatory ratios suggest a role of vitamin D in maintaining an anti-inflammatory environment at low levels of CRP, an association that is weaker at high CRP levels in subjects with subclinical inflammatory situations.

Conclusion

These data point to a possible role of vitamin D as a contributing factor in balancing cytokines toward an anti-inflammatory role in inflammatory situations.

Relationship between leptin levels and suppressed CD4 counts in HIV patients

OBJECTIVE

To examine the relationship between serum leptin levels and suppression of CD4 count in HIV-infected individuals with highly active antiretroviral therapy (HAART).

SUBJECTS AND METHODS

Thirty seropositive HIV male patients selected from the Infectious Disease Hospital were classified into two groups according to their immunological and virological response to HAART. The first group included 15 male patients with low viral load and low CD4 counts; the second included 15 male patients with low viral load and high CD4 counts. Morning serum leptin and tumor necrosis factor-α levels of HIV patients were measured and correlated with fasting serum insulin, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR), HIV viral load and CD4 count.

RESULTS

Serum leptin levels were significantly higher in patients with high CD4 counts than in patients with low CD4 counts (mean serum leptin level 47.3 vs. 10.9 ng/ml, respectively; p < 0.0001). A positive correlation was observed between serum leptin levels and CD4 counts (r = 0.697; p < 0.0001); positive correlations were also seen between leptin levels and fasting serum insulin and HOMA-IR (r = 0.633, p < 0.0001, and r = 0.537, p < 0.003, respectively).

CONCLUSION

Serum leptin level was higher in HIV patients with high CD4 count and correlated with fasting serum insulin and HOMA-IR, thereby indicating that HAART treatment could lead to decreased levels of leptin in HIV patients, which might lead to impaired immunological recovery.

Evaluation of bone mineral density in postmenopausal women in Kuwait

Menopause is the major risk factor for the loss of bone mineral density (BMD) and bone mineral content (BMC) in women. In this study, we determined the prevalence of osteoporosis in postmenopausal women in Kuwait and compared it with that of other Middle East and west countries. Two thousand two hundred ninety-six postmenopausal women ranging in age from 40 to 87yr were included in the study and divided into 4 age groups by decade. We measured body weight, height, body mass index (BMI), BMD, and BMC. The mean age, height, and weight were 59.1+7.9yr, 154.7+6.5cm, and 77.3+14.9kg, respectively. The mean BMI and BMC were 32.4+6.6kg/m(2) and 0.9+0.14g/cm(2), respectively. The average T-scores for the hip and lumbar spine were -0.280+1.2 and -1.297+1.33, respectively. BMC significantly decreased with age from 0.95 to 0.81g/cm(2). Four hundred forty-four (19.3%) were found to have osteoporosis. The incidence of osteoporosis significantly increased from 4.3% to 39.9% with age, which is lower than that reported for Saudi (40%) and Moroccan women (39.6%) and higher than that for US/European (31%) and Lebanese women (11%).

Progesterone-induced blocking factor (PIBF) modulates cytokine production by lymphocytes from women with recurrent miscarriage or preterm delivery

Spontaneous miscarriage and preterm delivery are common complications of pregnancy. Pro-inflammatory cytokines have been shown to be associated with recurrent spontaneous miscarriage (RSM) and preterm delivery (PTD) and these have led to exploration of ways to downregulate pro-inflammatory cytokines and/or to upregulate anti-inflammatory cytokines. Progesterone-induced blocking factor (PIBF) is a molecule with inhibitory effects on cell-mediated immune reactions. We have ascertained the effects of PIBF on secretion of selected type 1 and type 2 cytokines by peripheral blood mononuclear cells from healthy non-pregnant women, women undergoing normal pregnancy, women with unexplained RSM and women with PTD. Peripheral blood mononuclear cells from 30 women with a history of unexplained RSM, 18 women undergoing PTD, 11 women with normal pregnancy and 13 non-pregnant healthy women were stimulated with a mitogen in the absence and presence of PIBF after which the levels of cytokines released into culture supernatants were determined by ELISA. Production of the type 2 cytokines IL-4, IL-6 and IL-10 by lymphocytes from the RSM and PTD groups and of IL-4 and IL-10 by lymphocytes from healthy pregnant women was significantly increased upon exposure to PIBF, while the levels of type 1 cytokines were not affected. Ratios of type 1:type 2 cytokines were decreased, suggesting a shift towards Th2 bias. PIBF did not affect cytokine production by lymphocytes from non-pregnant women. Thus, PIBF acts on lymphocytes in pregnancy to induce a type 1 to type 2 cytokine shift by upregulating the production of type 2 cytokines.

Redirection of cytokine production by lymphocytes from women with pre-term delivery by dydrogesterone

PROBLEM

To study the ability of dydrogesterone to modulate the production of pro-inflammatory and anti-inflammatory cytokines by lymphocytes from women undergoing pre-term delivery (PTD).

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMC) from 18 subjects undergoing PTD were stimulated with the mitogen phytohemagglutinin in the presence and absence of progesterone and dydrogesterone. The levels of interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-10 in culture supernatants were then estimated by enzyme-linked immunoabsorbant assay. Cytokine production in the presence and absence of progesterone and dydrogesterone were compared.

RESULTS

The exposure of PBMC to dydrogesterone resulted in a significant inhibition in the production of the pro-inflammatory cytokines IFN-gamma and TNF-alpha and a significant increase in the levels of the anti-inflammatory cytokine IL-4, resulting in a substantial shift in the ratio of Th1/Th2 cytokines.

CONCLUSION

Dydrogesterone induces a shift in cytokine bias, by inhibiting pro-inflammatory cytokine production and increasing anti-inflammatory cytokine production.

Modulation of cytokine production by dydrogesterone in lymphocytes from women with recurrent miscarriage

OBJECTIVE

To examine the effects of dydrogesterone on the production of Th1 and Th2 cytokines by lymphocytes from women undergoing unexplained recurrent spontaneous miscarriage (RSM).

DESIGN

Controlled prospective, clinical study conducted in a maternity hospital and a university-based immunology laboratory.

SETTING

Faculty of Medicine, Kuwait University and Kuwait Maternity Hospital.

SAMPLE

Thirty women with unexplained RSM.

METHODS

Peripheral blood mononuclear cells (PBMC) from women with unexplained RSM were isolated from venous blood by density gradient sedimentation and stimulated with phytohaemagglutinin (PHA). Culture supernatants assayed for interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-4, IL-6 and IL-10 by ELISA. Levels of the progesterone-induced blocking factor (PIBF) were also measured.

MAIN OUTCOME MEASURES

Cytokine production in the presence and absence of progesterone and dydrogesterone.

RESULTS

Dydrogesterone significantly inhibited the production of the Th1 cytokines IFN-gamma (P= 0.0001) and TNF-alpha (P= 0.005) and induced an increase in the levels of the Th2 cytokines IL-4 (P= 0.03) and IL-6 (P= 0.017) resulting in a substantial shift in the ratio of Th1/Th2 cytokines. The effect of dydrogesterone was blocked by the addition of the progesterone-receptor antagonist mifepristone, indicating that dydrogesterone was acting via the progesterone receptor. Dydrogesterone induced the production of PIBF.

CONCLUSION

Dydrogesterone inhibits the production of the Th1 cytokines IFN-gamma and TNF-alpha from lymphocytes and up-regulates the production of the Th2 cytokines IL-4 and IL-6, inducing a Th1 to Th2 cytokine shift.

Maternal Cytokine Production Patterns in Women with Pre-eclampsia

PROBLEM

To determine the levels of cytokines produced upon mitogenic or antigenic stimulation of maternal peripheral blood mononuclear cells (PBMC) from women with pre-eclampsia.

METHOD OF STUDY

PBMC from 54 women with a history of successful pregnancy and 32 women undergoing pre-eclamptic delivery were stimulated with a mitogen or with autologous placental cells or with trophoblast antigens, and the levels of cytokines released into the culture supernatants then assessed by enzyme-linked immunosorbent assay.

RESULTS

Significantly higher levels of the Th1 cytokines, interferon-gamma, and tumor necrosis factor-alpha were produced by the pre-eclamptic group than by the normal pregnancy group, which on the contrary showed significantly greater production of the Th2 cytokines, interleukin (IL)-4, IL-5, IL-6 and IL-10. A comparison of the ratios of Th2 to Th1 cytokines indicates a higher Th1 cytokine bias in pre-eclampsia as compared with normal pregnancy.

CONCLUSIONS

These data are suggestive of a maternal pro-inflammatory cytokine bias in pre-eclampsia.

Th1/Th2 cytokine patterns and clinical profiles during and after pregnancy in women with multiple sclerosis

Pregnancy in multiple sclerosis (MS) patients is associated with a lower risk of progression and lower rate of exacerbation. These beneficial effects are reversed postpartum. Considering that the pathogenesis of MS appears to involve cell-mediated immune reactivity, and that pregnancy is accompanied by a depressed cell-mediated immunity, it has been proposed that the lower relapse rate and risk of progression of MS during pregnancy may be due to a pregnancy-associated down-regulation of cell-mediated immunity. In addition, pregnancy results in a shift towards a T helper (Th) 2 cytokine profile, which is presumably protective for MS. This study was aimed at investigating the relationship between clinical status of MS and cytokine levels in eight patients with MS who were followed through pregnancy and after delivery. Peripheral blood lymphocytes from these women were stimulated with a mitogen at different time points during and after gestation and the levels of Th1 cytokines (IFNgamma, TNFalpha) and Th2 cytokines (IL-4, IL-10) were estimated by ELISA. It was established that six of the eight MS patients studied showed a distinct shift from a Th2 cytokine bias during pregnancy towards a Th1 cytokine bias after delivery. These results suggest a possible association between decreased incidence of exacerbation of MS in pregnancy and a pregnancy-induced shift towards Th2 cytokine bias.

Increased Expression of Pro-Inflammatory Cytokines in Placentas of Women Undergoing Spontaneous Preterm Delivery or Premature Rupture of Membranes

PROBLEM

The objective of this study was to determine the levels of cytokines in the placentas of women undergoing preterm delivery (PTD) or premature rupture of membranes (PROM) as compared with women undergoing normal delivery at term.

METHOD OF STUDY

Placentas were obtained from 30 subjects with spontaneous PTD, 30 women with PROM and 30 women with a history of normal delivery at term. Levels of interleukin (IL)-2, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, TNF-beta, IL-4, IL-5, IL-6 and IL-10 and IL-12 were estimated by ELISA in detergent lysates of placentas from the subjects.

RESULTS

We found significantly increased levels of the Th1 cytokines IL-2 and IFN gamma and of the Th1-inducing cytokine IL-12 in placentas from the PTD and PROM groups as compared with those delivering at term. In contrast, the levels of the Th2 cytokines IL-4, IL-6 and IL-10 were significantly higher in placentas from term pregnancy.

CONCLUSIONS

These data support our observation of a pro-inflammatory cytokine bias in women with PTD and PROM.

Pro-inflammatory maternal cytokine profile in preterm delivery

PROBLEM

The objective of this study was to determine the levels of cytokines produced by maternal peripheral blood mononuclear cells (PBMC) upon stimulation with a mitogen, with autologous placental cells and with a trophoblast antigen extract.

METHOD OF STUDY

Peripheral blood mononuclear cells from 54 women with a history of successful pregnancy and 30 women undergoing preterm delivery (PTD) were stimulated with the mitogen and antigens, and the cytokine levels in mitogen-stimulated culture supernatants assessed.

RESULTS

Significantly higher levels of the type 1 cytokines, interferon (IFN)-gamma and interleukin (IL)-2, were produced by the PTD group than by the normal pregnancy group, which on the contrary showed significantly greater production of the type 2 cytokines, IL-4, IL-5 and IL-10. A comparison of the ratios of type 2 to type 1 cytokines is indicative of a type 1 cytokine bias in PTD.

CONCLUSIONS

These data are suggestive of a maternal type 1 cytokine bias in PTD.

Th1 and Th2 cytokine profiles in recurrent aborters with successful pregnancy and with subsequent abortions

BACKGROUND

This study compared Th1-Th2 cytokine profiles in a subgroup of recurrent aborters who had an abortion with those in a subgroup of recurrent aborters who had a successful pregnancy.

METHODS

Fifty-four women with a history of at least three normal pregnancies, 24 women with a history of recurrent spontaneous abortion (RSA) followed by abortion (RSA-->A) and 39 women with a history of RSA followed by normal pregnancy (RSA-->N) were studied. Blood samples and placentas were obtained at the time of delivery or abortion; peripheral blood mononuclear cells were stimulated separately with phytohaemagglutinin and with autologous placental cells, and the secreted cytokines estimated.

RESULTS

Peripheral blood mononuclear cells from the RSA-->N subgroup secreted higher concentrations of Th1-type cytokines as compared with normal pregnant women, indicating a higher Th1 bias in these women. However, women in the RSA-->N subgroup had significantly higher concentrations of Th2 cytokines as compared with women in the RSA-->A subgroup. A comparison of Th1:Th2 cytokine ratios indicated a higher Th2 bias in RSA-->N women as compared with RSA-->A women.

CONCLUSIONS

We conclude that abortion-prone women who proceed to have successful pregnancy are more Th2-biased than abortion-prone women who abort, and that recurrent aborters who undergo spontaneous abortion have a stronger Th1 bias than aborters who have normal pregnancy.

Cytokine patterns in maternal blood after premature rupture of membranes

OBJECTIVE

To compare two types of cytokines, type 1, which activate cell-mediated reactions and are important in cytotoxic and delayed-type hypersensitivity reactions, and type 2, which encourage vigorous antibody production and are commonly found in association with humoral immune responses, in blood of women with premature rupture of membranes (PROM).

METHODS

Forty-four women with histories of at least three successful pregnancies and who currently delivered normally served as controls. The PROM group consisted of 30 women with spontaneous rupture of fetal membranes at term. Peripheral blood mononuclear cells were stimulated separately with a mitogen, placental cells, and a trophoblast antigen extract, and the supernatants examined for type 1 and type 2 cytokines.

RESULTS

Mitogen-stimulated blood cells produced significantly higher levels of type 1 cytokines in PROM women than in normal controls. Higher levels of the type 1 cytokine interferon-gamma were produced by PROM samples stimulated with autologous placental cells and with trophoblast antigens. Ratios of type 1 to type 2 cytokines were higher in PROM compared with normal pregnancy, and in some cases as much as 25-fold higher.

CONCLUSION

Women in the PROM group had a stronger type 1 reactivity whereas normal women were more predisposed to type 2 immunity; thus, PROM appears to be associated with a maternal type 1 bias.

Th1 and Th2 cytokine profiles in sickle cell disease

We have investigated the levels of Th1 (IL-2 and IFN-gamma) and Th2 (IL-4) cytokines in the plasma and supernatants following peripheral blood mononuclear cell culture and mitogen stimulation in a group of 39 patients with sickle cell disease (SCD) made up of 29 SS, 8 Sbeta-thal and 2 Hb SD in steady state. Five SS patients were studied during 7 episodes of vaso-occlusive crisis. Twenty-four control (3 Hb AS and 21 Hb AA) were also studied; 10 were acutely ill while 14 were healthy at the time of the study. The plasma levels of IL-2 and IFN-gamma were similar in the patients and the controls. However, plasma IL-4 was significantly higher among the steady-state SS patients than in the controls. While there was no significant difference in cytokine levels following mitogen stimulation in the different groups, plasma IL-2 to IL-4 and IFN-gamma to IL-4 ratios were significantly lower among the steady-state SS patients, indicating a possible Th2 bias in our sickle cell patients and suggesting a possible mechanism to explain the predisposition of SCD patients to bacterial infections. However, SS patients with good splenic function showed a relative Th1 bias, which may be an additional explanation for the protection against bacterial infections in such patients.

Circulating cytokines and CD30 in normal human pregnancy and recurrent spontaneous abortions

Concentrations of the T-helper (Th) 1 cytokines interleukin (IL)-2, tumour necrosis factor (TNF) -alpha, TNF-beta and interferon-gamma, Th2 cytokines IL-4, IL-5, IL-6, IL-10 as well as those of soluble CD30 in sera have been examined during the three trimesters of gestation, at delivery in normal pregnancy, and at the time of spontaneous abortion in women with a history of unexplained recurrent spontaneous abortion (RSA). Significantly higher concentrations of the Th2 cytokines IL-6 and IL-10 were found at normal delivery than in women with RSA, and conversely significantly increased concentrations of the Th1-type cytokine TNF-alpha were found in RSA as compared with successful pregnancy. In abortion-prone women who had a successful pregnancy, significantly higher concentrations of IL-6 and significantly lower concentrations of TNF-alpha were found as compared with abortion-prone women who had another abortion, supporting the notion that Th2- and Th1-bias are associated with successful and unsuccessful pregnancy respectively. Serum CD30 concentrations did not correlate with the outcome of pregnancy. These findings support observations drawn from experiments on the cytokine secretion profiles of peripheral blood mononuclear cells and decidual lymphocytes which suggest that normal pregnancy is Th2-biased and that unexplained RSA is associated with Th1-type reactivity.

Tumor necrosis factor-alpha is undetectable in the plasma of SS patients with elevated Hb F

Steady-state sickle cell disease (SCD) patients may have increased plasma levels of acute phase reactants and pro-inflammatory cytokines because of subclinical inflammation. We have estimated TNF-alpha levels in the plasma and in supernatants following peripheral blood mononuclear cell (PBMC) activation with phytohemagglutinin (PHA) in a group of Kuwaiti SCD patients using ELISA. The group consisted of 28 SS, 8 Sbeta-thal, and 2 SD patients all in steady state; 5 SS patients were studied during 7 episodes of painful crisis. The subjects were aged 2 to 16 years, with a mean of 7.3 +/- 3.5 years. The beta(S)-globin gene cluster haplotype, alpha-tha1 status, and spleen function were determined in the SS group using standard techniques. Most (82%) were homozygous for the Saudi Arabia/India haplotype and had elevated Hb F levels ranging from 15% to 35%. There were 24 controls (Hb AA or AS), of whom 14 were healthy and 10 were acutely ill at the time of the study. None of the children with SCD (either in steady state or crisis) had detectable plasma TNF-alpha, but four controls (3 acutely ill and one healthy) had levels ranging from 61.7 to 249.8 pg/mL. Following PHA stimulation most subjects responded with high levels of TNF-alpha, with the median level among the steady-state SS patients being significantly higher than that in the controls (both the acutely ill or healthy). It therefore appears that because of the mild disease among our Arab SS children, TNF-alpha is not detectable in their plasma in steady state; these children, however, had a significantly higher response than controls following PBMC activation.

GM-CSF in sickle cell anemia patients with elevated Hb F

We estimated plasma GM-CSF levels in a group of 28 steady-state sickle cell anemia (SS) patients in Kuwait, using an ELISA technique. There were 24 age-matched Hb AA controls, 14 of whom were healthy while 10 were acutely ill at the time of the study. Five SS patients were also studied during 6 episodes of painful crisis. Among the SS patients, 82.1% were homozygous for the Saudi Arabia/India (SAI) haplotype with Hb F ranging from 15 to 35% and total Hb from 8.5 to 11 g/dl. Three patients (siblings) were SAI/Benin compound heterozygotes with Hb F of 9-23% and total Hb >10 g/dl. One patient each was homozygous for the Benin or the Bantu haplotype; they had Hb F <2% and total Hb of 6.6 and 7.2 g/dl, respectively. Four (14. 3%) steady-state SS patients had detectable plasma GM-CSF ranging from 75 to 1,817.6 pg/ml. These included the 2 patients with Hb F <2. 0% and 2 with the SAI/Benin compound heterozygotes with Hb F of 11 and 9%, respectively. Four (66.7%) SS patients in crisis, 6 (42.9%) healthy controls and 6 (60%) acutely ill controls had detectable plasma GM-CSF. A clearcut association of GM-CSF with Hb F level or degree of anemia in steady-state SS patients could not be established. The appearance of GM-CSF in the plasma of patients in crisis and also among control subjects raises the possibility that other factors are involved in the production of this cytokine in the subjects studied.

Cytokine production by maternal lymphocytes during normal human pregnancy and in unexplained recurrent spontaneous abortion

It has been proposed that successful pregnancy is a T helper 2-type phenomenon, and that T helper (Th)1-type reactivity is deleterious to pregnancy. The objective of this study was to compare the concentrations of Th1 and Th2 cytokines produced by peripheral blood mononuclear cells from women undergoing unexplained recurrent spontaneous abortion (RSA) with those produced during normal pregnancy at a similar gestational stage. The control group consisted of 24 women with a history of successful pregnancies and the abortion group comprised of 23 women with a history of unexplained RSA. Blood from the control group was obtained at the end of the first trimester as gestational age controls for the abortion group from whom blood was collected at the time of abortion. Phytohaemagglutinin-stimulated peripheral blood cell culture supernatants were analysed for concentrations of cytokines. Significantly higher concentrations of Th2 cytokines were produced by the first trimester normal group than by the RSA group, while significantly higher concentrations of Th1 cytokines were produced by the abortion group as compared to first trimester normal pregnancy, indicating a distinct Th2-bias in normal pregnancy and a Th1-bias in unexplained RSA.

Th1-type cytokines production is decreased in kidney transplant recipients with active cytomegalovirus infection

Cytomegalovirus (CMV) infection is a major complication after kidney transplantation. Despite antiviral therapy the infection contributes significantly to high morbidity. The present study was aimed at determining: (a) the stimulation index (S.I.) of phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) and (b) the levels of Th1- and Th2- related cytokines in kidney transplant recipients with and without active CMV infection. Thirty-five patients with, and 44 without active CMV infections, as diagnosed by a CMV antigenemia assay, were inducted into this study. After PHA stimulation of PBMC from patients, stimulation index (S.I.) was determined by radioactive thymidine uptake while the production of Th1-type cytokines (interleukin-2 [IL-2], interferon-gamma [IFN-gamma], and tumor necrosis factor-alpha [TNF-alpha]) and Th2-type cytokines (IL-4, IL-10) were measured by enzyme-linked immunosorbent assay. PBMC of patients with active CMV infection showed significantly lower S.I. values than patients without an ongoing CMV infection (P <.0001). Levels of Th2-type cytokines in CMV-infected and uninfected kidney recipients were similar; however, the levels of the Th1-type cytokines were significantly lower in CMV-infected patients. Low levels of Th1-type cytokines seem to correlate well with active CMV infection in kidney recipients.

Sequential production of cytokines by dengue virus-infected human peripheral blood leukocyte cultures

The study was undertaken to elucidate the sequence of appearance of T helper (Th)1- and Th2-type cytokines in human peripheral blood leucocyte cultures infected in vitro with dengue type 2 virus. Commercial sandwich enzyme-linked immunosorbent assay kits were used to assay the levels of tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10 in culture supernatants. Culture supernatants were also screened for the cytotoxic factor and the dengue virus titres determined. The cytokines that appeared in the culture supernatants on the first day post-infection (p.i.) were cytotoxic factor, TNF-alpha, IL-2, and IL-6; their levels were highest on the second day p.i. IFN-gamma appeared on the second day with a peak on the third day p.i. The levels of these cytokines declined quickly, except for human cytotoxic factor (hCF) and IL-2. The cytokines that appeared later were IL-10 and IL-5 on the fourth day and IL-4 on the sixth day p.i. Dengue virus replicated in the peripheral blood leucocyte (PBL) cultures and was present throughout the course of the study. The findings of the present study show that dengue virus induced a predominant Th1-type cytokine response during the first 3 days of infection of PBL cultures that was replaced by a Th2-type response later.

Mitogen-induced cytokine responses of maternal peripheral blood lymphocytes indicate a differential Th-type bias in normal pregnancy and pregnancy failure

PROBLEM

Profiles of Th1- and Th2-type cytokines were studied in women with a history of successful pregnancy and in women with a history of unexplained recurrent spontaneous abortions (RSA) with the objective of elucidating Th1- and Th2-type bias in normal pregnancy and pregnancy failure.

METHOD OF STUDY

Peripheral blood mononuclear cells (PBMCs) from 54 women with a history of normal pregnancy and 23 women with a history of unexplained RSA, obtained at delivery or on the day of abortion, respectively, were stimulated with phytohemagglutinin (PHA), followed by the estimation of four Th2 cytokines and four Th1 cytokines.

RESULTS

Significantly greater levels of Th2 cytokines were produced by the normal group than by the RSA group. On the other hand, significantly higher levels of Th1 cytokines were produced by the RSA group than by the normal pregnancy group.

CONCLUSIONS

These data support the concept that unexplained recurrent spontaneous abortion is associated with an increase in Th1-type reactivity, while Th2 dominance is a feature of successful pregnancy.

Sequential production of cytokines by dengue virus-infected human peripheral blood leukocyte cultures

The study was undertaken to elucidate the sequence of appearance of T helper (Th)1- and Th2-type cytokines in human peripheral blood leucocyte cultures infected in vitro with dengue type 2 virus. Commercial sandwich enzyme-linked immunosorbent assay kits were used to assay the levels of tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10 in culture supernatants. Culture supernatants were also screened for the cytotoxic factor and the dengue virus titres determined. The cytokines that appeared in the culture supernatants on the first day post-infection (p.i.) were cytotoxic factor, TNF-alpha, IL-2, and IL-6; their levels were highest on the second day p.i. IFN-gamma appeared on the second day with a peak on the third day p.i. The levels of these cytokines declined quickly, except for human cytotoxic factor (hCF) and IL-2. The cytokines that appeared later were IL-10 and IL-5 on the fourth day and IL-4 on the sixth day p.i. Dengue virus replicated in the peripheral blood leucocyte (PBL) cultures and was present throughout the course of the study. The findings of the present study show that dengue virus induced a predominant Th1-type cytokine response during the first 3 days of infection of PBL cultures that was replaced by a Th2-type response later.

A placenta-derived suppressor factor with a T-cell bias

PROBLEM

Functional and mechanistic aspects of immunosuppression by murine placental supernatants (MPS) were investigated.

METHOD OF STUDY

MPS and a low molecular weight fraction of the supernatant (MPSf) were tested for suppressive action on T-cell reactivity in vitro and in vivo, on B-cell responses and on T-cell activation events.

RESULTS

MPS and MPSf suppress mitogen-induced proliferation and mixed lymphocyte reactions of human and murine lymphocytes, antigen-induced proliferation of T cells in vitro and in vivo, proliferation of CD8+ lymphocytes, proliferation induced by cross-linking of surface CD3 and the in vivo response of mice to allogeneic stimuli. MPSf affects cell cycling of activated T cells and blocks interleukin (IL)-2 production. MPSf does not affect antibody production or the induction of MHC class II expression on B cells.

CONCLUSIONS

MPSf is a potent inhibitor of T-cell responses in vitro and in vivo, with no demonstrable effect on B-cell function.

Maternal Th1- and Th2-type reactivity to placental antigens in normal human pregnancy and unexplained recurrent spontaneous abortions

Spontaneous abortion is the most common complication of pregnancy, but the etiology of a significant proportion of abortions is still unknown. We have examined the production of Th1- and Th2-type cytokines by women with unexplained recurrent spontaneous abortion (RSA) since it appears that successful murine pregnancy occurs in a Th2-dominant situation and that Th1-type immunity is associated with pregnancy failure. We have compared maternal reactivity toward placental antigens in women with a history of successful pregnancy with that in women with a history of RSA. This was done by coculturing maternal peripheral blood mononuclear cells (PBMC) with autologous placental cells and also by stimulating maternal PBMC with antigens from a choriocarcinoma cell line of trophoblastic origin. We detected significantly greater levels of the Th2 cytokines IL-6 and IL-10 in normal pregnancy compared to unexplained RSA and significantly higher levels of the Th1 cytokine IFN-gamma in RSA compared to normal pregnancy. These results suggest that women with normal pregnancy have a higher Th2 bias, while women with a history of RSA evince a bias toward Th1-type reactivity.

Elevated levels of IL-8 in dengue hemorrhagic fever

Dengue virus causes dengue fever, a mild febrile illness, and at times dengue hemorrhagic fever (DHF), a severe illness the pathogenesis of which is not fully understood. Given the crucial roles played by interleukin-8 (IL-8) as a chemoattractant cytokine and in inflammatory processes, levels of circulating IL-8 in the sera and IL-8 mRNA in the peripheral blood mononuclear cells (PBMC) were measured in 99 patients of a recent dengue epidemic that occurred in India in 1996 and in 21 normal healthy controls. Twenty-six of the patients had dengue fever (DF) and the remaining 73 were diagnosed as having different grades of DHF. All the control normal sera were negative for IL-8, so were their PBMC for IL-8 mRNA. Increased levels of IL-8 in the sera and IL-8 mRNA in their PBMC were observed in patients with severe illness of DHF grades III and IV. Only two out of 26 patients of DF and one out of 10 DHF grade I patient were positive for IL-8 and all three deteriorated to DHF grade IV within 24 hr. All six patients of DHF grade IV who died had higher serum level of IL-8 above 200 pg/ml, the highest being 5,568 pg/ml in one patient; the presence of mRNA for IL-8 was very high in all patients. A striking correlation was observed between increased levels of IL-8 and severe DHF, with greater levels in patients with increased grade of the disease and death. These results suggest that IL-8 may have an important role and may be an indicator of increasing severity of the disease and death.