Tyrosine kinase-1 and endoglin blamed for preeclampsia

Researchers today blamed two placenta produced proteins to be the main cause of Preeclampsia, a disorder fatal to the mother as well as the child.

Preeclampsia is said to be present when hypertension arises in pregnancy in association with significant protein in the urine. Abnormal levels of protein is the main cause and early detection can prove beneficial.

Dr. Elias Zerhouni, director of the National Institutes of Health, said that the research has opened new doors to find the cures for the disorder.

In 2003, one of the scourging proteins was discovered. Research was done on rodent’s year’s back, which suggested that injecting the protein mimics a few symptoms of the disorder. Latest research, done with the pair of proteins on rodents, elucidated the fact that the combined effect of both the proteins was more fatal, together producing the full spectrum of symptoms.

The early symptoms of the disorder are Hypertension, sudden weight gain, headache, nausea or vomiting, Changes in vision, racing pulse, mental confusion, heightened anxiety, trouble catching breath, stomach or right shoulder pain, pain in the lower back, hyperreflexia. High blood pressure and 300 mg of protein in a 24 hour urine sample (proteinuria) are also the symptoms of Preeclampsia. Swelling or edema (especially in the hands and face) was originally considered an important sign for a diagnosis of preeclampsia, but in current medical practice only hypertension and proteinuria are necessary for a diagnosis.

Dr. Richard J. Levine of the National Institute of Child Health and Human Development, who led the study, said that there are many more factors affecting the development of the disorder, but the two proteins play the major roles.

Dr. Marshall D. Lindheimer of the University of Chicago and Dr. Jason G. Umans of Georgetown University said the research has thrown sufficient light on the once cryptic disease. The recent study can be used to find out its cures and predictions.

Preeclampsia is much more common in the first pregnancy and usually becomes evident in a three month time period. It is also more common in women who have preexisting hypertension, diabetes, autoimmune diseases like lupus, various inherited thrombophilias like Factor V Leiden, or renal disease, in women with a family history of preeclampsia, and in women with a multiple gestation (twins, triplets and more). The single most significant risk for developing preeclampsia is having had preeclampsia in a prior pregnancy.

Usually diagnosed late in pregnancy, preeclampsia can progress to eclampsia, a serious complication of pregnancy that is characterized by convulsions. The convulsions may appear before, during or after labour, though cases of eclampsia after just 20 weeks of pregnancy have been recorded. About 15% of maternal deaths are caused by eclampsia.

Management of preeclampsia has centered on aggressive maternal and fetal assessment and earliest safe delivery. Frequent monitoring of maternal blood pressure, urinary protein excretion, weight change, and symptoms is compulsory. Regular biophysiologic assessment of the fetus is also substantive.

If the preeclampsia is mild and blood pressure is adequately controlled with no signs of imminent seizure, patients may be managed at home with bed rest.

Soluble fms-like tyrosine kinase-1, a protein which disables proteins that cause blood vessel growth, was founded in 2003 by Dr. S. Ananth Karumanchi of the Beth Israel Deaconess Medical Center in Boston and his colleagues, when they discovered increased levels of tyrosine in women suffering from preeclampsia.

The team looked at blood samples from women with preeclampsia and found the second protein, called endoglin that is also present in abnormally high levels in women with the disorder. Endoglin is also one of the major players for restricting the normal growth of blood vessels.

Proof suggests that the disorder is sparked when the fetus is unable to absorb oxygen from the placental blood supply. Responding to this condition, placenta ejects the two proteins into the bloodstream, which in turn hamper the growth of the blood vessels.

The fetus starts getting more oxygen due to the increased blood pressure, but health of the mother is in peril.

Preeclampsia and other hypertensive disorders of pregnancy are a leading global cause of maternal and infant illness and death. By conservative estimates, these disorders are responsible for 76,000 deaths each year. The disorder, once known as toxemia, affects as many as 8% of pregnancies.