Alfredo Leaños-Miranda

Urinary prolactin as a reliable marker for preeclampsia, its severity, and the occurrence of adverse pregnancy outcomes.

CONTEXT It has been proposed that preeclampsia may result from of an imbalance in angiogenic factors. Although prolactin (PRL) is mainly related to lactation, it is also involved in other biological functions, including angiogenesis. OBJECTIVE Our objective was to determine the relationship among preeclampsia, serum and urinary PRL (uPRL) levels, and excretion of antiangiogenic PRL fragments in urine. STUDY DESIGN Using a cross-sectional design, uPRL and serum PRL levels, and the presence of PRL isoforms were determined in 546 pregnant women: 207 healthy pregnant, 124 with gestational hypertension, 48 with mild preeclampsia, and 167 with severe preeclampsia (sPE). RESULTS uPRL concentrations were significantly (P < 0.001) higher in preeclampsia (11.99 ng/mg creatinine) than in healthy pregnancy (0.20 ng/mg creatinine) and gestational hypertension (0.19 ng/mg creatinine), and were even higher in sPE compared with mild preeclampsia (21.20 vs. 2.77 ng/mg creatinine, respectively; P < 0.001). Antiangiogenic PRL fragments (14-16 kDa) were detected in 21.6% of urine samples from women with sPE but in none from other groups. Patients with hemolysis, elevated liver enzymes, low platelet count syndrome, and/or eclampsia, placental abruption, acute renal failure, and pulmonary edema exhibited highest uPRL concentrations (P < or = 0.028) and frequency of antiangiogenic PRL fragments in urine (P < or = 0.036). High-serum PRL levels were associated with sPE independently of gestational age, proteinuria, and prolactinuria (P = 0.032). CONCLUSIONS Preeclampsia is characterized by increased uPRL excretion. uPRL concentrations and their isoforms appear to be suitable markers to assess the severity of preeclampsia and occurrence of adverse outcomes. PRL and and/or its isoforms might be involved in the pathophysiology of preeclampsia.

Biologic activity and plasma clearance of prolactin–IgG complex in patients with systemic lupus erythematosus

OBJECTIVE To characterize the clinical findings in hyperprolactinemic systemic lupus erythematosus (SLE) patients with or without macroprolactinemia (big, big prolactin [PRL]) due to anti-PRL autoantibodies (PRL-IgG complex), and to assess the bioactivity and structure of big, big PRL. METHODS Twenty-seven SLE patients with hyperprolactinemia (HPRL) were studied. Patients with (n = 8) or without (n = 19) big, big PRL were identified by gel filtration chromatography and affinity chromatography for IgG. PRL concentrations in serum and fractions by gel filtration chromatography and affinity chromatography were characterized by immunoradiometric assay (IRMA), Nb2 bioassay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting, and clearance studies. RESULTS SLE patients without big, big PRL had significantly higher levels of disease activity, cause-proven HPRL, and menstrual disturbances compared with patients with big, big PRL (P < or = 0.05). The big, big PRL fractions by Western blotting revealed a single 23-kd nonglycosylated PRL. The Nb2:IRMA ratio of the samples with big, big PRL was significantly higher than that of the samples without big, big PRL (P < or = 0.02). However, bioactivity of big, big PRL in the Nb2 cells was very similar to that of 23-kd nonglycosylated PRL. Clearance studies in rats demonstrated that the PRL-IgG complex was eliminated more slowly than monomeric PRL (little PRL). CONCLUSION We demonstrated that the PRL-IgG complex was formed by 23-kd nonglycosylated PRL that was noncovalently bound to IgG and showed that the complex was fully active in vitro. This result suggests that the absence of symptoms of HPRL or lower levels of lupus activity in these patients is not explained by lower bioactivity of the complex. Instead, because of the large molecular size of the complex, the PRL does not easily cross the capillary walls. Delayed clearance of the PRL-IgG complex may account for increased serum levels of PRL in SLE patients with anti-PRL autoantibodies.

Association of the Plasminogen Activator Inhibitor-1 Gene 4G/5G Polymorphism With ST Elevation Acute Myocardial Infarction in Young Patients

INTRODUCTION AND OBJECTIVES To investigate the role of the 4G/5G polymorphism in the plasminogen activator inhibitor-1 (PAI-1) gene in patients with ST-elevation myocardial infarction (STEMI) aged < or =45 years and its influence on regulation of the plasma PAI-1 concentration. METHODS This case-control study included 127 consecutive patients aged < or =45 years with a diagnosis of STEMI who were admitted to a cardiovascular intensive care unit and 127 controls recruited between January 2006 and March 2007. Participants were genotyped for the 4G/5G polymorphism using the polymerase chain reaction and restriction fragment length polymorphism analysis, and their plasma PAI-1 concentrations were measured. Informed consent was obtained from all participants. RESULTS There was a significant difference in genotype distribution between the two groups (P< .002). The 4G allele occurred more frequently in the patient group (P=.032). In addition, there were significant independent associations between STEMI and the 4G allele (i.e., 4G/4G plus 4G/5G; odds ratio [OR]=2.29; 95% confidence interval [CI], 1.12-4.68; P=.022), smoking (OR=23.23; 95% CI, 8.92-60.47; P< .001), a family history of cardiovascular disease (OR=4.66; 95% CI, 2.06-10.52; P=.001) and hypertension (OR=5.42; 95% CI, 1.67-17.56; P=.005). The plasma PAI-1 concentration was higher in individuals who were homozygous for the 4G allele (P< .001). CONCLUSIONS The study findings indicate that the 4G allele is an independent risk factor for acute myocardial infarction in young patients, as are smoking, hypertension and a family history of inherited cardiovascular disease.

Misrouted cell surface receptors as a novel disease aetiology and potential therapeutic target: the case of hypogonadotropic hypogonadism due to gonadotropin-releasing hormone resistance

Molecules that are incorrectly folded or defectively assembled are recognised by cellular quality control mechanisms. This leads such conformationally abnormal molecules to intracellular retention and eventual degradation. A number of diseases caused by mutations that interfere with proper processing and intracellular trafficking of key cell surface proteins have been described. These include a particular variant of hypogonadotropic hypogonadism, which results from mislocalisation of the gonadotropin-releasing hormone (GnRH) receptor. It has been shown recently that membrane expression and function of misfolded GnRH receptor mutants can be rescued by a peptidomimetic antagonist of GnRH (IN3) that permeates into the cell and reaches the abnormally manufactured nascent receptor, stabilising a conformation compatible with cell-surface transport and reversing intracellular retention. This approach seems applicable for the development of defined therapeutic strategies for an array of diseases caused by incorrectly routed cell surface or secreted proteins.

Changes in circulating concentrations of soluble fms-like tyrosine kinase-1 and placental growth factor measured by automated electrochemiluminescence immunoassays methods are predictors of preeclampsia.

Objective: Preeclampsia is characterized by an imbalance in angiogenic factors such as soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF). We herein assessed whether these factors measured by a newly developed automated electrochemiluminescence immunoassay are associated with risk to develop preeclampsia. Methods: We performed a nested case–control study within a cohort of 230 women with singleton pregnancies. The study included all 37 women who eventually developed preeclampsia and 29 normotensive controls. Serum samples were collected at 4-week intervals (from weeks 20th to 36th). sFlt-1 and PlGF were measured using a commercial automated immunoassay (Elecsys). Results: Women destined to develop preeclampsia had lower PlGF levels and higher sFlt-1 levels and sFlt-1/PlGF ratio than women with normal pregnancies. These changes became significant at 20 weeks in women destined to develop early preeclampsia (<34 weeks, P ⩽ 0.003), and at 24–28 weeks in women who later developed preeclampsia (P ⩽ 0.024). The risk for developing preeclampsia was higher among women with PlGF concentration values in the lowest quartile or with sFlt-1 levels and sFlt-1/PlGF ratio in the highest quartile of the control distribution. The odds ratios were higher and appeared earlier in women destined to develop early preeclampsia than in women who presented preeclampsia later. The sFlt-1/PlGF ratio was more tightly associated with risk of preterm or term preeclampsia than either angiogenic factor alone. Conclusion: Changes in circulating concentrations of PlGF, sFlt-1, and in the sFlt-1/PlGF ratio precede the onset of preeclampsia. The risk profile of circulating angiogenic factors for developing preeclampsia distinctly evolves depending on whether this condition is manifested at preterm or term.

Circulating Angiogenic Factors and Urinary Prolactin as Predictors of Adverse Outcomes in Women With Preeclampsia

Preeclampsia is characterized by an imbalance in angiogenic factors. Urinary prolactin (PRL) levels and its antiangiogenic PRL fragments have been associated with disease severity. In this study, we assessed whether these biomarkers are associated with an increased risk of adverse maternal and perinatal outcomes in preeclamptic women. We studied 501 women with preeclampsia attended at a tertiary care hospital. Serum concentrations of soluble fms-like tyrosine kinase-1 (sFlt-1), placental growth factor (PlGF), and soluble endoglin (sEng), as well as urinary PRL levels, were measured by enzymed-linked immunosorbent assay. Antiangiogenic PRL fragments were determined by immunoblotting. The risk for any adverse maternal outcome and for having a small-for-gestational-age infant was higher among women with sFlt-1/PlGF ratios, sEng, and urinary PRL level values in the highest quartile (odds ratios ≥2.7), compared with the lowest quartile. Both urinary PRL levels and the presence of antiangiogenic PRL fragments were more closely associated with the risk of specific adverse maternal outcomes (placental abruption, hepatic hematoma or rupture, acute renal failure, pulmonary edema, maternal death, and need for endotracheal intubation, positive inotropic drug support, and hemodialysis; odds ratios ≥5.7 and ≥4.7, respectively) than either sFlt-1/PlGF ratio or sEng alone. We concluded that in preeclamptic women at the time of initial evaluation, sFlt-1/PlGF ratio and sEng are associated with increased risk of combined adverse maternal outcomes. However, urinary PRL concentrations and its antiangiogenic fragments appear to be better predictors of an adverse maternal outcome and may be useful for risk stratification in preeclampsia.

Application of new homologous in vitro bioassays for human lactogens to assess the actual bioactivity of human prolactin isoforms in hyperprolactinaemic patients

Background   Prolactin (PRL) plays a central role in mammary gland development and lactation. Due to its molecular heterogeneity, measurement of PRL immunoreactivity does not necessarily reflect its intrinsic bioactivity. For many years the Nb2 rat lymphoma cell bioassay has been the only reference bioassay for human lactogens. This bioassay, however, does not always correlate with the clinical features found in some patients exhibiting normal or elevated immunoreactive serum PRL concentrations.

The Glu298ASP polymorphism of the endothelial nitric oxide synthase gene is associated with premature ST elevation myocardial infarction in Mexican population

BACKGROUND The polymorphism Glu298Asp of endothelial nitric oxide (eNOS) gene has been associated with hypertension and coronary artery disease in several populations worldwide, but results are still controversial. We examined the possible association of the Glu298Asp with premature ST elevation myocardial infarction (STEAMI) in young Mexican population. METHODS In a case-control study 180 unrelated patients with STEAMI < or =45years who were admitted to a cardiovascular intense care unit and 180 apparently healthy controls matched by age and gender were recruited from January 2006 to June 2009. The polymorphism Glu298Asp was determined in all participants by a polymerase chain-reaction-restriction fragment length polymorphism assay (PCR-RFLP). RESULTS There was a significant difference in the genotype distribution between 2 groups (P=0.001). The allele Asp occurred more frequently in the patients group (P=0.001). There were independent factors for STEAMI: the Asp allele (OR 2.2, 95% CI 1.1-3.5, P=0.03), smoking (OR 5.0, 95% CI 3.1-8.2, P<0.001), hypertension (OR 2.0, 95% CI 1.0-3.5, P=0.03), family history of cardiovascular disease, (OR 3.7, 95% CI 2.0-4.6, P=0.02), and dyslipidemia (OR 3.4, 95% CI 2.0-6.3, P=0.02). CONCLUSIONS The Asp allele from the Gu298Asp polymorphism represents an independent risk factor for premature STEAMI in Mexican Mestizo population.

Analysis of anti-prolactin autoantibodies in systemic lupus erythematosus.

Evidence has shown that prolactin is an essential component of an effective immune response. In systemic lupus erythematosus, clinical trials have produced controversial information about the role of PRL. Some results find association between serum PRL levels and disease activity. In contrast, other authors did not find this. Recently, autoantibodies against prolactin in SLE patients have been described. One hundred percent of SLE patients with anti-PRL autoantibodies had hyperprolactinemia (hPRL) and 31.7% of the SLE patients classified with idiopathic hPRL had anti-prolactin antibodies. A similar result was found in 103 pediatric SLE patients. The patients with idiopathic hyperprolactinemia and anti-PRL autoantibodies had less clinical and serological lupus activity than the SLE patients with idiopathic hyperprolactinemia, but without anti-PRL autoantibodies. This evidence suggests that anti-PRL autoantibodies or the complex with any other molecule, like macroprolactinemia (big-big PRL) could have attenuated biological activity and this could explain why some clinical studies did not find any association between serum PRL levels and disease activity in SLE patients. However, studies in vitro have shown normal or elevated biological activity in Nb2 cell lines using PRL from serum with anti-PRL autoantibodies from patients with or without autoimmune diseases. Several conclusions could be drawn. One is that while a set of hyperprolactinemic SLE patients display autoantibodies against PRL, it is not clear what role these autoantibodies play in the whole system. However, until now, we knew that the patients with antibodies to PRL lacked the clinical symptoms of hyperprolactinemia such as menstrual disturbances and/or galactorrhea and show less clinical and serological lupus activity.

The C677T Polymorphism of the Methylenetetrahydrofolate Reductase Gene Is Associated with Idiopathic Ischemic Stroke in the Young Mexican-Mestizo Population

Background and Purpose: Previous studies have demonstrated that a common polymorphism in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with an increased risk for stroke. However, this relation remains controversial. Our aim was to investigate the possible association between the C677T polymorphism in the MTHFR gene and idiopathic ischemic stroke in the young Mexican-Mestizo population. Methods: One hundred seventy-eight patients <45 years with idiopathic ischemic stroke and 183 controls were tested for the C677T polymorphism in the MTHFR gene. Causes of primary thrombophilia as well as classical risk factors for atherothrombotic disease were also evaluated. Results: There was a significant difference in the genotype distribution between patients and controls (p = 0.01), but the allele frequency was similar in both groups (p = 0.09). The univariate analysis identified the T allele as a risk factor for ischemic stroke (TT and CT carriers), as compared with homozygous for C allele (p = 0.01). Hypertension and smoking prevalences were significantly higher in the group of patients. Also the T allele was significantly associated with large-vessel ischemic stroke. The postoral methionine load homocysteine levels were higher in patients with ischemic stroke versus controls (p < 0.001). There was a low prevalence of primary thrombophilia markers. Conclusions: The T allele from the C677T polymorphism of the MTHFR gene represents an independent risk factor for idiopathic ischemic stroke at young age in the Mexican-Mestizo population. Also, hypertension and smoking were independent risk factors in our study population. Primary thrombophilic risk factors were not associated with ischemic stroke in our population.