A K-negative patient was able to avoid complications associated with hemolytic disease of the fetus and newborn (K-HDFN) with administration of immune-modulating therapies, according to a case report published recently in the journal Cureus.
The report described a 32-year-old K-negative female who was pregnant for the second time. Her first pregnancy resulted in the birth of a healthy baby seven years prior to the study.
The patient became sensitizedSensitization The process by which a mother’s immune system becomes “primed” to recognize and attack fetal red blood cells carrying incompatible antigens. against the K antigen at the time of her previous pregnancy. Her sensitizationSensitization The process by which a mother’s immune system becomes “primed” to recognize and attack fetal red blood cells carrying incompatible antigens. to the K antigen likely occurred during her prior uneventful pregnancy with her K-positive husband.
Standard-of-care therapy for K-sensitized pregnancies typically involves the utilization of watchful waiting and IUTIntrauterine transfusion A procedure that delivers donor red blood cells to the fetus through the umbilical vein to treat severe anemia caused by HDFN., but if left untreated, K-HDFN can lead to the development of severe anemiaAnemia A condition that occurs when the body doesn’t have enough healthy red blood cells to carry oxygen to its tissues. In HDFN, anemia occurs when maternal antibodies destroy fetal red blood cells.. In fact, early pregnancy is known to be the time when the use of IUT is less feasible.
In an effort to avoid the development of HDFN, the patient underwent preventive treatment to decrease her immune response.
Prophylactic therapy and delivery of a healthy baby
The pregnant patient underwent three rounds of therapeutic plasma exchange (TPE), which were able to lower her anti-K antibodyAntibody A protein made by the immune system that recognizes and attacks foreign substances, such as bacteria, or in HDFN, fetal red blood cells carrying incompatible antigens. titer. The TPE was followed by weekly intravenous immunoglobulinIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus. (IVIGIntravenous immunoglobulin A therapy made from donated antibodies that may help reduce the mother’s immune response and protect the fetus.) infusions, which were administered at a dosage one g/kg of body weight.
In addition, she underwent middle cerebral artery peak systolic velocity (MCA-PSVDoppler ultrasound A non-invasive scan that measures blood flow speed in the fetus' brain to diagnose anemia. Specifically, it checks the middle cerebral artery peak systolic velocity (MCA-PSV).) Doppler imaging to monitor for the presence of fetal anemia.
Read more about the testing and diagnosis of HDFN
Ultimately, the fetus required the administration of two intrauterine transfusions (IUTs) in the woman’s third trimester.
She delivered a healthy baby at 36 weeks’ gestational age. Mild anemia and a positive direct antiglobulin testDirect antiglobulin test A blood test used to detect antibodies attached to red blood cells. It helps confirm HDFN in newborns. were reported.
“It is possible that this pregnancy may have been viable without the TPE/IVIG therapy,” the authors noted. “[I]t is also possible that this pregnancy might have ended in severe early anemia and fetal death.”
K sensitization is both dangerous and unpredictable in pregnancy. The use of a combination therapeutic regimen of TPE/IVIG provides a possible “way for clinicians to protect their pregnant patients from the uncertainty of HDFN.”
The results of this report are in accordance with many other small case studies in which a link between a combined TPE/IVIG treatment regimen and satisfactory outcomes has been noted.
