Autoimmune hemolysis is defined as accelerated destruction of erythrocytes by antibodies directed against red cell membrane proteins. During pregnancy, this hemolytic process gets aggravated. The cause of aberrant antibody production in this uncommon condition is unknown. Anemias caused by these factors may be due to warm-active antibodies (80 to 90 percent), cold-active antibodies, or a combination. Cold-agglutinin disease may be induced by infectious etiologies such as Mycoplasma pneumonia or Ebstein-Barr viral mononucleosis. Hemolysis and positive antiglobulin test results may be the consequence of either IgM or IgG anti-erythrocyte antibodies. Spherocytosis and reticulocytosis are characteristic of the peripheral blood smear.
Here we will describe the case of a 23-year-old woman, who presented during her first pregnancy with severe autoimmune haemolytic anaemia (AIHA) due to idiopathic warm antibody (IgG) which developed in the early second trimester of pregnancy. Her haemolytic process was responsive to steroid therapy and blood transfusions. She delivered a healthy male baby at 32 weeks of birth weight of 1.5 kg with mild hyperbilirubinemia.
autoimmune haemolytic anaemia, direct antiglobulin test, pregnancy, hyperbilirubinemia.
Unexplained severe hemolytic anemia sometimes develops during early pregnancy and resolves within months post-partum. Autoimmune haemolytic anaemia (AIHA), caused primarily by pregnancy, is poorly described in the literature[1,2,3,4]. AIHA is characterized by the development of antibodies directed against oneís own red cell antigens. These syndromes may be classified as primary (idiopathic) or secondary due to underlying diseases or other factors. Examples of the latter include lymphomas and leukemias, connective-tissue diseases, infections, chronic inflammatory diseases, and drug-induced antibodies. When such an autoantibody belongs to the IgG class, the condition is potentially dangerous to both the mother and the fetus, since IgG crosses the placenta readily. In most reported cases, idiopathic AIHA occurred late in the pregnancy and responded well to steroid therapy and/or transfusions, with slight or no haemolytic process in the newborn.
Case Report :
A 23- year-old pregnant female reported to our antenatal clinic at 15 weeks gestation with features of severe anemia which required immediate admission and blood transfusion. She did not have any prior history of blood transfusion in the past or any symptoms of any infection during her pregnancy and the only drugs she had been taking was oral iron, calcium and folic acid tablets.
On admission the patient complained of generalized weakness and easy fatiguability. Clinically the patient was both pale and icteric. Physical examination showed tachycardia and tachypnea. The fetal status was normal. Her investigations revealed her Hb to be 6.8, Direct Coombs Test (DCT) was positive, PCV 21.1, MCV 119.9, MCH 38.6, MCHC 32.3, Total WBC count 13500 and platelets 3.11 lakhs. She received two units of PRBC which raised her Hb to 9.4 as measured 48 hours after the transfusion. All other investigations including serum iron, ferritin, total iron binding capacity (TIBC), transferin saturation and serum folate and vitamin B12 levels were normal. Her peripheral smear showed evidence of hemolysis.
Fig. 1. Peripheral smear showing acanthocytes and poikilocytes.
She was then started on oral prednisolone with 40 mg (Wysolone) tablets once daily which corresponded to a dose of 1mg/kg body weight (approx.). The patient's body weight was 43 kgs. Her complete blood count (CBC) and DCT was repeated weekly and if her Hb level was above 9 then the dose of prednisolone was tapered down by 10 mg per week. Her DCT showed falling titres which was initially positive at 1:64 at the time of diagnosis. She received two further units of PRBC transfusion at 28th week when her Hb again fell to 7 gm/dl. After that she was managed solely on oral prednisolone. Iron supplementation was stopped after AIHA was diagnosed, but she continued to receive calcium and folic acid tablets. Her dose of oral prednisolone was tapered weekly up to 20 mg daily and then she was given 20 mg and 15 mg on alternate days. Fetal status was checked weekly by Doppler study of uumbilical and middle cerebral artery from the 28th week onwards which was normal. Her pregnancy continued uneventfully till the 32nd week when she was admitted again for excessive vaginal discharge. She was diagnosed with bacterial vaginosis (BV) according Amsel's criteria and was treated with Clindamycin ovules, 100 mg, intravaginally once at bedtime for 3 days. But on the 4th day after her admission she experienced preterm prelabour rupture of membranes and she was started on parenteral antibiotic for the prevention of chorioamnionitis. But her liquor subsequently became meconium stained and she had to be taken up for an emergency caesarean section for fetal distress. She delivered a male baby of 1.5 kgs which was otherwise healthy. The baby was admitted in the NICU for low birth weight and developed mild jaundice after 24 hours. Total bilirubin was 13.9 with unconjugated being 13. The Direct Coomb's Test of the baby was negative. The baby was managed on phototherapy.
Unfortunately, this condition has rarely been reported in literature, and not enough data are available for management of such cases, especially when steroidal treatment fails and there are challenges in determining criteria for fetal prognosis. Pathogenesis must be further studied, keeping in mind the feto-placental immunological, hormonal and biochemical factors that could be responsible for this condition occurring during pregnancy and disappearing post partum.
Fortunately in our case the severe hemolytic process responded well to steroids and blood transfusions. There was no evidence of hemolytic disease of the newborn as evidenced by the negative DCT.