From the Guidelines
The patient's increasing lactate dehydrogenase (LDH) and decreasing hemoglobin (Hg) likely indicate hemolysis, which is the breakdown of red blood cells, as almost anything that results in cellular lysis or injury can cause elevations of LDH 1. This pattern is characteristic of hemolytic anemia, where red blood cells are destroyed faster than they can be replaced. The elevated LDH occurs because this enzyme is released from damaged red blood cells into the bloodstream, while hemoglobin decreases as red blood cells are destroyed. Some possible causes of this condition include:
- Autoimmune conditions like autoimmune hemolytic anemia
- Medications (such as certain antibiotics, quinine, or ribavirin)
- Infections
- Inherited disorders like sickle cell disease or thalassemia
- Mechanical heart valves
- Microangiopathic processes like DIC or TTP Management depends on identifying the underlying cause, which requires additional testing such as a peripheral blood smear, reticulocyte count, direct Coombs test, and haptoglobin level. Treatment may include corticosteroids (prednisone 1-2 mg/kg/day) for autoimmune causes, discontinuation of offending medications, or specific treatments for underlying conditions, and in severe cases, blood transfusions may be necessary, though these should be approached cautiously in autoimmune hemolysis as they can exacerbate the condition, and extended matched red cells should be considered 1. It is crucial to initiate supportive care, including erythropoietin with or without IV iron, and a shared decision-making process is critical in managing such cases 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Possible Causes of Increasing LDH and Decreasing Hemoglobin
- Hemolysis: a condition where red blood cells are destroyed faster than they can be made, leading to an increase in lactate dehydrogenase (LDH) and a decrease in hemoglobin (Hg) 2, 3, 4, 5
- Anemia: a condition where the body does not have enough red blood cells or the red blood cells do not have enough hemoglobin, leading to a decrease in Hg 2, 3, 6, 4
- Thrombotic thrombocytopenic purpura (TTP): a rare blood disorder that can cause hemolysis, leading to an increase in LDH and a decrease in Hg 2
- Paroxysmal nocturnal hemoglobinuria (PNH): a rare blood disorder that can cause hemolysis, leading to an increase in LDH and a decrease in Hg 4
- Cardiogenic shock with a trans valvular micro-axial flow pump: a condition where the heart is not pumping enough blood, leading to an increase in LDH and a decrease in Hg 5
Relationship Between LDH and Hemoglobin
- LDH is an enzyme found in red blood cells, and when these cells are destroyed, LDH is released into the bloodstream, leading to an increase in LDH levels 2, 3, 4, 5
- Hemoglobin is a protein in red blood cells that carries oxygen, and when red blood cells are destroyed, hemoglobin levels decrease 2, 3, 6, 4
- An increase in LDH and a decrease in Hg can indicate hemolysis or anemia 2, 3, 4, 5
Studies Supporting the Relationship Between LDH and Hemoglobin
- A study published in the American Journal of Hematology found that a patient with TTP had an increase in LDH and a decrease in Hg 2
- A study published in Herz found that a patient with aortic valve replacement had an increase in LDH and a decrease in Hg 3
- A study published in Drugs in R&D found that patients with PNH treated with pegcetacoplan had an increase in Hg and a decrease in LDH 4
- A study published in Artificial Organs found that patients with cardiogenic shock and a trans valvular micro-axial flow pump had an increase in LDH and a decrease in Hg 5