Human mid-gestation amniotic fluid contains interleukin-16 bioactivity

The role of IL‑16 gene polymorphisms in endometriosis

Endometriosis is one of the most common gynecological diseases affecting up to 10% of the female population of childbearing age and a major cause of pain and infertility. It is influenced by multiple genetic, epigenetic and environmental factors. Interleukin-16 (IL-16) is a proinflammatory cytokine playing a pivotal role in many inflammatory and autoimmune diseases as well as in the pathogenesis of endometriosis. The aim of the present study was to evaluate the association of two IL-16 gene single nucleotide polymorphisms (SNPs), rs4072111 and rs11556218, with the risk of endometriosis in women from Greece as well as to gain insight about the structural consequences of these two exonic SNPs regarding development of the disease. A total of 159 women with endometriosis (stages I–IV) hospitalized for endometriosis, diagnosed by laparoscopic intervention and histologically confirmed, and 146 normal controls were recruited and genotyped. Subjects were genotyped using a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) strategy. A significant association was detected regarding the GG and GT genotype as well as 'G' allele of rs11556218 in patients with endometriosis. The rs4072111 SNP of the IL-16 gene was not found to be associated with an increased susceptibility to endometriosis either for all patients (stages I–IV) or for stage III and IV of the disease only. Our results demonstrated that rs11556218 is associated with endometriosis in Greek women, probably by resulting in the aberrant expression of IL-16, as suggested by the bioinformatics analysis conducted on the SNP-derived protein sequences, which indicated a possible association between mutation and functional modification of Pro-IL-16.

Placental Growth Factor, Soluble fms-Like Tyrosine Kinase 1, Soluble Endoglin, IL-6, and IL-16 as Biomarkers in Preeclampsia

Preeclampsia (PE), an important cause of maternal and perinatal morbidity and mortality worldwide, is a pregnancy-related disease characterized by hypertension and proteinuria after 20 weeks of gestation. The aim of our study was to find a practical panel of biomarkers useful in early diagnosis of PE. This study was carried out at the Obstetrics and Gynecology Department in Tîrgu Mureș University Hospital, Romania, between January 2014 and July 2015 and included 68 pregnant women (47 preeclamptic women and 21 controls) with gestational age between 16 and 20 weeks at enrollment. The biomarkers PlGF, sFlt-1, sEng, IL-6, and IL-16 were determined by ELISA test. We compared the serum levels of soluble markers analysed in preeclamptic women and controls during the second and third trimesters of pregnancy and we found that the best predictor for PE was PlGF with a sensitivity of 100% at a concentration threshold of 120.16 pg/mL, a diagnosis accuracy of 70.8%, and AUC of 0.684 (p = 0.005). We also estimated the risk for PE according to BMI and we found that pregnant women with weight >90 kg had 7 times higher risk for PE. Second-trimester PlGF serum level may serve as an early biomarker for the diagnosis of PE.

Association of interleukin-16 polymorphisms with disease progression and susceptibility in endometriosis

Interleukin-16 (IL-16) is a multifunctional pro-inflammatory cytokine that was previously found in association with complex disorders, and it is now cleared that this cytokine plays a critical role in regulation of cellular functions such as homoeostasis. Due to the complexity of endometriosis and its resemblance to cancer, we designed present case-control study to determine the effects of genetic polymorphisms of the human IL-16 gene on Iranian women's susceptibility to endometriosis. A total of 126 patients with endometriosis (stages I-IV) and 144 healthy women as control group were recruited to the study. We genotyped four single nucleotide polymorphisms of IL-16 gene (rs11556218 T>G, rs4778889 T>C, rs4072111 C>T and rs1131445 C>T). Genotyping was performed using PCR and restriction fragment length polymorphism. Our results showed that genotype distribution in two exonic polymorphisms including rs11556218 and rs4072111 was significantly different between Endometriosis patients and healthy individuals (P < 0.05). We have also found an association between rs4072111 and rs1131445 with progression to the severe stages (III-IV) of endometriosis (P < 0.05). Finally, we may conclude that IL-16 gene polymorphisms are highly associated with increased risk of endometriosis and could be considered as a susceptibility factor for endometriosis.

Reductions in circulating levels of IL-16, IL-7 and VEGF-A in myalgic encephalomyelitis/chronic fatigue syndrome

Recently, differences in the levels of various chemokines and cytokines were reported in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) as compared with controls. Moreover, the analyte profile differed between chronic ME/CFS patients of long duration versus patients with disease of less than 3years. In the current study, we measured the plasma levels of 34 cytokines, chemokines and growth factors in 100 chronic ME/CFS patients of long duration and in 79 gender and age-matched controls. We observed highly significant reductions in the concentration of circulating interleukin (IL)-16, IL-7, and Vascular Endothelial Growth Factor A (VEGF-A) in ME/CFS patients. All three biomarkers were significantly correlated in a multivariate cluster analysis. In addition, we identified significant reductions in the concentrations of fractalkine (CX3CL1) and monokine-induced-by-IFN-γ (MIG; CXCL9) along with increases in the concentrations of eotaxin 2 (CCL24) in ME/CFS patients. Our data recapitulates previous data from another USA ME/CFS cohort in which circulating levels of IL-7 were reduced. Also, a reduced level of VEGF-A was reported previously in sera of patients with Gulf War Illness as well as in cerebral spinal fluid samples from a different cohort of USA ME/CFS patients. To our knowledge, we are the first to test for levels of IL-16 in ME/CFS patients. In combination with previous data, our work suggests that the clustered reduction of IL-7, IL-16 and VEGF-A may have physiological relevance to ME/CFS disease. This profile is ME/CFS-specific since measurement of the same analytes present in chronic infectious and autoimmune liver diseases, where persistent fatigue is also a major symptom, failed to demonstrate the same changes. Further studies of other ME/CFS and overlapping disease cohorts are warranted in future.

Normative levels of Interleukin 16 in umbilical cord blood

OBJECTIVES

The need for early and accurate prediction of outcome in hypoxic-ischaemic encephalopathy (HIE) remains critical. We have previously demonstrated that Interleukin 16 (IL-16) is raised in the umbilical cord blood (UCB) of infants with moderate and severe HIE and has the potential to be developed as a predictive biomarker. Normal reference ranges for IL-16 in UCB have not been previously described. The aim of this study was to determine normative levels of IL-16 in full term neonates using UCB following uncomplicated deliveries and to examine the effect of labour on cord IL-16 values.

DESIGN AND METHODS

Full term infants were recruited as part of an ongoing birth cohort study, the Cork BASELINE Birth Cohort Study. All had UCB drawn and bio-banked at -80°C, within 3hours of birth. Samples for this experiment were chosen from this population based cohort study to represent uncomplicated pre-labour caesarean sections and spontaneous vaginal deliveries. Analysis was performed on plasma EDTA, using ELISA Quantikine® (R&D Systems, Europe).

RESULTS

Samples were analysed from 48 infants with two modes of delivery; spontaneous vaginal delivery (n=12 male, n=12 female) and elective caesarean section (n=12 male, n=12 female). The range of all samples was normally distributed between 87.0 and 114.6pg/ml. Overall mean (SD) for IL-16 was 102.9 (21.5) pg/ml. Levels were not affected by spontaneous vaginal delivery or gender.

CONCLUSION

For the first time we have described the expected range of cord plasma IL-16 levels in healthy term infants following pre-labour and post-labour delivery.

Immunological and biochemical markers in preeclampsia

A basic precondition for the development of preeclampsia is the presence of placental trophoblast cells in the maternal blood circulation. On the other hand, while trophoblast cells are present in the blood of all pregnant women, preeclampsia occurs in only 2-5% of them. Evidently, other factors play a crucial role. The aim of this study was to compare a set of selected immunological factors (anti-cardiolipin autoantibodies, trophoblast-induced cell-mediated immunity, C3 and C4 complement components) and biochemical factors (serum immunoglobulins IgA, IgG, IgM) among three groups of women with uncomplicated pregnancy, gestational hypertension, or preeclampsia. Blood samples were taken 2-12h before delivery. In the preeclampsia group, there was a significantly higher number of women positive for anti-cardiolipin autoantibodies, trophoblast-induced cell-mediated immunity was elevated, serum IgG was elevated and C4 complement component was reduced. We conclude that both elevated autoimmune reactivity and the higher immune reactivity to trophoblast may contribute to the onset of preeclampsia.