What happens in red blood cells
The G6PD enzyme triggers reactions that supply the cell with reduced glutathione, a substance that neutralizes aggressive oxidants. The red blood cell does not have a nucleus and does not know how to synthesize proteins again, so this is the only way for it. With a lack of enzyme, any strong oxidizing agent damages hemoglobin, it precipitates, the cell membrane becomes rigid, and the spleen destroys such red blood cells. Massive cell death in a short time is a hemolytic crisis.
- The enzyme protects the red blood cell from oxidation
- The gene defect is located on the X chromosome
- Men get sick more often, women are usually carriers
- Severity depends on mutation variant
- Between provocations, blood tests may be normal.
What triggers a crisis
The most famous provocateur is fava (garden) beans, hence the name “favism”: a reaction is possible even to inhaling pollen from flowering beans. A second important source of risk is drugs with oxidative effects, including some antimalarials, sulfonamides, nitrofurans, and drugs used to treat urinary tract infections. A simple infection with a high fever can also trigger a crisis. Therefore, with any prescription, the doctor should know about the diagnosis, and the patient should carry a reminder with him.
- Fava beans in any form, including fresh and dried
- Some antimalarial drugs
- Sulfonamides and nitrofurans
- Selected painkillers and antiseptics
- Naphthalene and products containing it for storing clothes
- Viral and bacterial infections, high fever
- Henna when applied to the skin of a newborn
Symptoms of hemolytic crisis
Complaints usually appear 1–3 days after contact with the provocateur. A child or adult becomes lethargic and pale, complains of dizziness and palpitations, the skin and whites of the eyes turn yellow, and the urine darkens due to the release of hemoglobin breakdown products. There may be back or abdominal pain, nausea, and fever. The severity varies greatly: from mild jaundice to severe anemia requiring hospitalization. In newborns, G6PD deficiency is manifested by prolonged jaundice.
- Pallor and severe weakness
- Yellow tint to the skin and sclera
- Dark urine the color of tea
- Palpitations and shortness of breath on exertion
- Lower back or abdominal pain
- In newborns - severe and prolonged jaundice
Diagnostics
During a crisis, a general blood test shows a decrease in hemoglobin, and reticulocytes increase - the bone marrow tries to make up for the loss. Indirect bilirubin and LDH increase, characteristically damaged red blood cells are visible in the smear. The main confirmatory test is to determine the activity of the G6PD enzyme in the blood. An important detail: immediately after a crisis, activity may appear falsely normal, because deficient cells are already destroyed, and young ones contain more enzyme. Therefore, the study is repeated after 2–3 months.
- Complete blood count with reticulocytes
- Indirect bilirubin and LDH
- General urine analysis and hemoglobin in urine
- Activity of the G6PD enzyme in the blood
- Repeated examination 2–3 months after the crisis
- Examination of relatives and genetic counseling
Treatment and prevention
There is no specific treatment that restores the enzyme, so the main task is to prevent crises. The patient is given a list of prohibited drugs and products, which must be shown to any doctor, including the dentist. When a crisis develops, the provocateur is immediately discontinued, sufficient fluids and observation are provided; if there is a significant drop in hemoglobin, red blood cell transfusion is performed in the hospital. Newborns with jaundice are given phototherapy. Preventive “blood cleanses” and dietary supplements are useless and dangerous.
- Complete refusal of fava beans and products containing them
- Coordination of each new drug with a doctor
- Wearing a reminder or bracelet with a diagnosis
- Early treatment of infections and reduction of fever
- Hospitalization for severe crisis
- Family genetic counseling