Hemoglobinuria - Causes, Symptoms, Pathophysiology, Diagnosis, and Treatment

Introduction:

Hemoglobin is a protein in the red blood cells that transport oxygen to the different body parts and carry carbon dioxide from the other organs and body parts back to the lungs. Hemoglobinuria is the presence of hemoglobin in urine. It happens due to the destruction of the red blood cells resulting in the excretion of hemoglobin in the urine, giving it a reddish color. Hemoglobinuria can occur in kids, adults, and pregnant women. It occurs due to kidney infection, kidney stones, pyelonephritis, or cancer.

What Are the Causes of Hemoglobinuria?

Various factors that cause hemoglobinuria are,

• Kidney stones.

• Tumors.

• Intake of toxic drugs.

• Pregnancy.

• Reaction to blood transfusion.

• Kidney Infarction is a sudden blockage of blood supply in the kidney blood vessels.

• Burns.

• Tuberculosis - A disease of the lungs.

• Paroxysmal Nocturnal Hemoglobinuria (PNH) - It is a rare blood disease. It is an acquired, life-threatening disease. PNH is caused by the destruction of red blood cells, the formation of blood clots, and weakened bone marrow function. It is associated with aplastic anemia.

• Drugs such as sulphonamides, quinine, and phenylhydrazine.

• Infections include malaria, blackwater fever, gas gangrene, yellow fever, and anthrax.

• Direct injury to the red blood cells due to exercise, heart surgery involving valve prosthesis.

• Microangiopathic Hemolytic Anemia (MAHA) - Any hemolytic anemia related to the breakdown of red blood cells, occurring in small blood vessel disease.

• Disseminated Intravascular Coagulopathy (DIC) - This is a rare condition that drastically interrupts blood flow. This is a blood clotting disorder that can lead to uncontrollable bleeding. It usually affects individuals with cancer or sepsis- the body’s response to a severe infection.

• Hemolysis or breakdown of red blood cells in the donor blood due to improper storage.

• Hemoglobinuria can also be caused due to excess cold.

What Is the Pathophysiology of Hemoglobinuria?

Breakdown of the red blood cells occurs at a specific gravity lower than 1.010. This happens due to the breakdown of the red blood cells in the urinary tract. The breakdown of red blood cells within the blood vessels leads to hemoglobinuria. No red blood cells are visible in such cases.

The free hemoglobin in the plasma splits into molecules. It attaches itself to a protein produced by the liver-haptoglobin forming a haptoglobin-hemoglobin complex that is not filtered by the kidneys. In certain conditions like hemolytic anemias, burns, reactions to blood transfusion, heavy exercise, and infections, hemoglobin becomes more than haptoglobin. This is because the free hemoglobin can pass through the tiny filters within the kidneys (glomeruli), whereas the excess is absorbed in some kidney tubules. Therefore, the free hemoglobin can easily pass out in the urine as hemoglobinuria. Hemoglobinuria can also occur because of the breakdown of the blood cells in the urinary tract.

What Are the Signs and Symptoms of Hemoglobinuria?

The symptoms of hemoglobinuria are as follows,

• The reddish color of the urine.

• Shortness of breath.

• Anemia - A decrease in the number of red blood cells in the body.

• Headache.

• Arrhythmia - The presence of an irregular heartbeat.

• Pain in the chest.

• Abdominal pain.

• Susceptibility to bruises.

• Blood clots.

• Yellow or pale skin.

How Is Hemoglobinuria Detected?

The diagnosis of hemoglobinuria is made based on,

• Medical history.

• Blood tests - A complete blood count is done to evaluate the cause of red blood cell breakdown.

• Serum Biochemistry - This test determines the factors causing hemolytic anemia.

• Urine Test - A urine sample is tested for hemoglobin or blood cells.

• Dipstick Method - A dipstick is a plastic strip with chemicals over it. It is dipped in the urine. The chemical strips change color when it comes in contact with certain substances like blood or hemoglobin in the urine.

• O-toluidine Test - It gives a blue color in the presence of hemoglobin.

How Is Hemoglobinuria Treated?

The treatment of hemoglobinuria is primarily symptomatic.

• Folic acid is prescribed to help the bone marrow make red blood cells.

• Use of iron supplements for new red blood cell generation.

• Ravulizumab - This medicine is used to avert the breakdown of red blood cells, thus improving anemia and reducing the formation of blood clots.

• Eculizumab - The mode of action of Eculizumab is similar to that of Ravulizumab, but the former has persisted longer. Patients are given six or seven infusions in a year.

• Pegcetacoplan - It is a therapy prescribed for patients who are new to the treatment.

• Blood transfusions.

• Bone Marrow Transplant - In the case of paroxysmal nocturnal hemoglobinuria, a bone marrow transplant is a necessary solution. This procedure gives healthy stem cells (immature cells that grow into different blood cells. These stem cells are formed in the bone marrow within the bones. In this procedure, the individual’s bone marrow that is not working well is damaged with drugs or radiation and replaced with the healthy bone marrow of a donor. This transplant is advised for patients who do not respond well to the drug Eculizumab or those with a severe reduction in red blood cells. A bone marrow transplant is also recommended for patients with severe disease.

• Blood Thinners - These medicines do not let the blood clot within the blood vessels.

• Eating a balanced and healthy diet. The body absorbs iron when it is eaten with vitamin C.

• Exercise - Instead of heavy and strenuous workouts, one should opt for slow activities that would not make the heart beat fast.

• Maintaining proper hygiene to avoid contracting unnecessary infections. Practices include regular washing of hands and avoiding crowded places and sick individuals.

• Vaccines such as flu shots can be taken to keep infections at bay.

Conclusion:

Hemoglobinuria is the presence of hemoglobin in the urine. Hemoglobin is the protein in the red blood cells that helps transport oxygen gas to various body parts and organs and carbon dioxide from the different organs and tissues back to the lungs. The life cycle of red blood cells is around one hundred and twenty days, after which it breaks down in the organ called the spleen, bone marrow, or liver.

If this breakdown occurs within the blood vessels, the different constituents, including hemoglobin, move to the kidneys, eventually filtered out through the urine, causing hemoglobinuria. However, the presence of hemoglobin in the urine is often not symptomatic; hence, it is usually detected by urine tests. Taking proper medications and maintaining a healthy lifestyle to treat the symptoms can help the individual to overcome the condition.