T Ahsan, F Wahab, M Kamal, S Islam
eclampsia, pre-eclampsia, serum immunoglobulins
T Ahsan, F Wahab, M Kamal, S Islam. Serum Immunoglobulins (IgG, IgA, IgM) levels in Preeclampsia and Eclampsia Pregnancies. The Internet Journal of Third World Medicine. 2008 Volume 8 Number 1.
Preeclampsia is the most common pregnancy-specific complication that still ranks as one of obstetrics major problems. It is a placenta dependent pregnancy disorder. Preeclampsia is associated with modulation of immune response and defective trophoblast invasion (1). Syndrome of preeclampsia is described as excessive maternal inflammatory responses, perhaps directed against foreign fetal antigens that induce a chain of events including surface trophoblast invasion, defective spiral artery remodeling, placental infarction and release of pro-inflammatory cytokines and placental fragments in the systemic circulation. Currently preeclampsia, consequently eclampsia are suggested to be caused by changes in immunity. Therefore, in addition to treating hypertension in preeclampsia, attempts of modifying immune responses may be a future treatment modality. There have been several observations on modulation of immune responses in pregnancy (2,3) and preeclampsia (1,4-9), most of which documented inflection of lymphocytes and cytokines. Report on immunoglobulin status is rare. We report here the serum IgG, IgA and IgM levels in preeclampsia and eclampsia patients.
Materials And Methods
Serum Immunoglobulins were estimated by solid phase indirect enzyme-linked immunosorbant assay (ELISA), as described by Islam (10). In brief, microtitre ELISA plates (Nunc Immuno plate, Denmark) were coated with 100 µl of anti-human IgG, IgA and IgM (Sigma Chemicals Company, USA; diluted 1:1000 with PBS), incubated overnight at 4ºC, washed (×3) with PBS (containing 0.5% Tween 20) and dried by wads of paper towels. The wells were blocked with 100 µl of sheep serum solution, incubated for 1 hour at 37ºC and treated as above. Then 100µl of diluted test sera and serially diluted standard immunoglobulins-IgG, IgA, IgM (Sera-Pak®, Immuno, Bayer, USA) were pipetted into the premarked wells, incubated and treated as above. Next, 100 µl of peroxidase-conjugated anti-human IgG, IgA or IgM of Sigma Chemicals Co., USA; diluted 1:500 with 0.1% BSA) was pipetted into each well and incubated and treated as above. Finally, 100 µl of substrate solution (0.001% tetramethylbanzidine in 0.1M sodium acetate buffer containing H2O2) was added to each well of the plates and incubated in the dark at room temperature for 50 minutes. Peroxidase reaction was stopped by adding 50 µl of 10% sulfuric acid to each well. The plates were read at 450nm in an ELISA plate reader (Labsystems, MultiskanEX, Finland).
Clinical parameters of preeclampsia, eclampsia and normotensive pregnant are shown in the table 1. The mean age of preeclampsia patient (27.18±6.49years) was found to be higher than the eclampsia patient (22.67±3.57years), but was equivalent to the normotensive pregnant (24.114.93years). Gestational age for preeclampsia and eclampsia were also matched. As anticipated, the mean systolic and diastolic blood pressures of eclampsia patient (162.78±20.17mmHg, 111.67±15.21mmHg respectively) were higher than the preeclampsia patient (143.18±12.3mmHg, 102.27 ± 6.47mmHg respectively).
*Values were expressed in meansd.
In preeclampsia patients, serum IgG, IgA and IgM concentrations were 7.95±0.69g/L, 4.07±0.32g/L and 2.01±0.21g/L; in eclampsia, it were 7.66±0.46g/L, 4.10±0.32g/L and 2.92±0.29g/L; and in normotensive pregnant, it were 7.10±0.61g/L, 3.65±0.32g/L and 2.16±0.16g/L respectively. There were no significant change in IgG and IgA between pre-eclampsia and eclampsia, but IgM level was found to be significantly higher in eclampsia than that in pre-eclampsia (t=7.87, p=0.0001). Compared to the normotensive pregnants, serum concentrations of all of the immunoglobulins were found significantly high in both pre-eclampsia and eclampsia (table 2). It was observed that except systolic blood pressure with IgG (r=0.689, p=0.04) and to some extent with IgA (r=-0.637, p=0.065), gestational age (r= -0.890, p=0.0001) and proteinuria (r=0.747, p= 0.008) with IgM; none of the maternal characteristics is associated with the serum immunoglobulins concentrations in pre-eclampsia or eclampsia. Multiple regression analysis did not show any effect of systolic or diastolic blood pressure on any of the serum immunoglobulins.
Preeclampsia affects 2.7% of all pregnancies with varying severity and it is a leading cause of maternal and fetal morbidity and mortality (9). In addition to etiopathophysiology hypothesis, it is suggested that preeclampsia may be caused by modulation or maladaptation of both adaptive and innate immunity (4). Several reports addressed modulation of lymphocyte populations and cytokine levels in preeclampsia (5-8). We report here the changes in serum immunoglobulin levels in preeclampsia and eclampsia patients.
Analysis of serum immunoglobulins showed that there was a significant increase of IgG, IgA and IgM in both pre-eclampsia and eclampsia as compared to normotensive pregnants. The raised immunoglobulin concentrations may be because of increased lymphocyte populations5, particularly of immunoglobulin producing B-lymphocytes. This study also observed that with few exceptions such as systolic blood pressure with IgG, and gestational age and proteinuria with IgM; none of the maternal characteristics is associated with the serum immunoglobulins concentrations in pre-eclampsia or eclampsia. It is revealed that serum immunoglobulins are found to be elevated in preeclampsia and eclampsia.
Authors thank the University of Dhaka for part financial support to conduct this study.