Volume 39 Number 2 | April 2025
Marionette Yvonne Agatep-Cortez, AHI, MLS(AMT), ASCLS Today Volunteer Contributor
Case Study
A 31-year-old female came to the emergency room complaining of light headedness, ketoacidosis, and stomachache. She is non-English speaking and needed a Haitian interpreter for communication purposes. She is eventually admitted for observation upon the physician’s receipt of her laboratory results. Six months prior, the patient gave birth at the same facility via Caesarian section. She had developed post-partum syndrome, diabetes mellitus, and vitamin D deficiency prompting for regular checkups.
On the first day of her admission, a pathologist consult was ordered due to the parameter that did not meet the facility criteria of a normal peripheral smear, many target cells. On the third day, another pathologist consult was sent for review due to the presence of Hemoglobin C (Hgb C) crystals on the peripheral smear, which appear as dense, rectangular, rod shaped tetragonal and hexagonal shaped crystals within the red blood cells as per CAP description. It is caused by a mutation in the beta-globin chain of hemoglobin, which results in reducing the solubility and crystal formations under oxygenated conditions, and again many target cells are noted. The pathologist agreed with the findings and recommended having the patient’s blood tested using Hemoglobin Electrophoresis, which can show abnormal hemoglobin levels or types that can indicate a hemoglobin disorder and to rule out what the patient has, whether it be Hgb C disease or Hgb C trait.
Going further to the investigative process and to better understand the medical situation, there is a need-to-know what hemoglobin does to the body. Hemoglobin as the textbook says, is a protein containing iron that facilitates the transportation of oxygen in the red blood cells. And there are different types of hemoglobin, one is Hemoglobin C, which is an abnormal form of hemoglobin and is hereditary, primarily found in West Africans and descendants from that area. In the United States, hemoglobin C occurs in 2 to 3 percent of the African American population.
Finally, the result of the Hemoglobin Electrophoresis came back, and it was concluded that the patient has Hemoglobin C disease. The determining factor is the amount of Hgb C present. If there is a low amount of Hemoglobin C, this indicates Hgb C trait; if the amount of Hgb C is high, then it is Hgb C disease. Additional information on the difference between Hgb C trait and Hgb C disease are the following.
Hgb C trait occurs when a person inherits one gene for Hgb C from one parent and one gene for Hgb A from the other parent and is considered a carrier state. This does not cause health problems; it is a chronic condition that does not need any treatment and is common to African American, Middle Eastern, and people of Mediterranean descent.
On the other hand, Hgb C disease has two Hemoglobin C genes, one from each parent, and it causes red blood cells to become less flexible and contain too much Hgb C. This can lead to anemia but usually does not cause symptoms or problems and is not fatal. People who have the condition live long. This commonly affects African Americans, who have a shorter lifespan than with normal RBC and can cause lightheadedness, fatigue, weakness, paleness of the skin, and can cause mild hemolytic anemia. Furthermore, it occurs in one out of 5,000 to 10,000 African Americans who live a normal life. Genetic counseling is recommended because Hgb C in combination with Hgb S can result in sickle cell disease.
We now know that this patient had the disease, but she was only diagnosed at postpartum. What do we mean when we say postpartum? It is simply the period when the physiological changes related to pregnancy return to the non-pregnant state. Post partum care is extended up to 12 weeks, but OBGYN patients may be considered postpartum for as long as 12 months after birth. The importance of Hgb C in postpartum women is because at childbirth women are at a higher risk of anemia due to the blood loss during delivery. With a high Hgb C level, it could exacerbate this issue, potentially leading to symptoms like fatigue and weakness. Always discuss the blood test results with the provider as Hgb C disease can cause complications during pregnancy and after delivery, especially when associated with sickle cell disease.
So why was it not detected that the patient had Hgb C prior to her admission six months ago when she gave birth? It is because Hgb C crystals are not always seen on a patient’s peripheral smear, as the spleen usually removes the crystals from circulation unless the patient has undergone splenectomy. With each pregnancy, there is a 25 percent (or one in four) chance of having a child with Hemoglobin C disease and a 50 percent (or one in two) chance of having a child with Hemoglobin C trait.
I dug deeper on the mother’s background since her chart says she does not speak English and needs a Haitian interpreter—meaning she is most likely from Haiti, and Haitians are of African descent with origins in West and Central Africa. She is married to a Caucasian, so the baby inherited one gene of the Hgb C from the mother and one gene of the Hgb A from the father, so the baby most likely inherited Hgb C trait, and the newborn screen says baby is a carrier of hemoglobinopathy.
References
- https://together.stjude.org/en-us/medical-care/inherited-risk-genetic-testing/hemoglobin-c-trait.html
- https://www.update.com/contents/overview-of-the-postpartum-period-normal-physiology-and-routine-maternal-care#text=Thepostpartumperiod
- College of American Pathologists Laboratory Quality Solutions 2025 Hematology and Clinical Microscopy Glossary pp 11. Erythrocyte Inclusions. Hemoglobin C Crystal
Marionette Yvonne Agatep-Cortez is an MLSII and Lead Laboratory Safety Officer at Columbus Regional Health in Columbus, Indiana.
Figure 1: Peripheral smear on admission
Figure 2: Peripheral smear exhibiting Hgb C crystals on third day