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In my blood test: hematie 5.88, hematocrite 51%, hemoglobine 17.8g/dl all other numbers are normal. I am worried about Hemoglobin level, is it too high/dangerous?? limit is 17g/dl. please advise thx
13 أغسطس 2014
The process of red blood cells manufacturing in the bone marrow (erythropoiesis) is tightly orchestrated; one of the important enzymes involved is called erythropoietin (Epo), mainly produced and released by the kidneys and to a smaller extent by the liver.
Polycythemia is classified as primary polycythemia or secondary polycythemia, depending on the underlying disturbance. Primary polycythemia, which is rare, results from internal malfunction with the production of red blood cells. Secondary polycythemia is caused by another underlying medical condition.
Primary polycythemia occurs due to either inherent or acquired problems with red blood cell production. Two main conditions that are included in this category are polycythemia vera (PV or polycythemia rubra vera [PRV]) and primary familial and congenital polycythemia (PFCP).
• Polycythemia vera (PV) is caused by a genetic mutation in the JAK2 gene, which is thought to increase the sensitivity of bone marrow cells to Epo, leading to increased red blood cell production. Levels of other types of blood cells (white blood cells and platelets) are concomitantly often increased in this condition.
• Primary familial and congenital polycythemia (PFCP) is a condition related to a mutation in the EPOR gene and causes increased production of red blood cells in response to Epo.
In secondary polycythemia, more red cells are produced because of high levels of circulating Epo. The major factors that induce higher than normal levels of Epo are chronic hypoxia (poor blood oxygen levels over the long-term), poor oxygen delivery due to abnormal red blood cell structure, and tumors releasing inappropriately high amounts of Epo.
Some of the common conditions that can result in elevated erythropoietin due to chronic hypoxia or poor oxygen supply include:
• chronic obstructive pulmonary disease (COPD, emphysema, chronic bronchitis),
• pulmonary hypertension,
• hypoventilation syndrome,
• congestive heart failure,
• obstructive sleep apnea,
• poor blood flow to the kidneys, and
• living in high altitudes.
There also are more benign conditions that may cause increase Epo secretion, such as kidney cysts and kidney obstruction.
Chronic exposure to carbon monoxide (CO) can lead to polycythemia. CO is one of the toxins released from cigarettes. Hemoglobin naturally has a higher affinity for carbon monoxide than for oxygen. So when carbon monoxide molecules attach to hemoglobin, polycythemia may occur in order to compensate for the poor oxygen delivery by the existing hemoglobin molecules.
Relative polycythemia comprises a number of conditions in which RBC volume is elevated due to increased blood concentration of red cells as a result of dehydration – this is known as hemoconcentration, whereby the RBCs cluster together and give a false impression of elevated Hgb/Hct. It is commonly seen in scenarios of vomiting, diarrhea, and excessive sweating, where the number of red blood cells is normal, but because of the fluid loss affecting the blood (plasma), red blood cell counts may seem elevated.
Stress erythrocytosis (also known as pseudopolycythemia or Gaisbock's syndrome) is seen in obese middle aged men who are being treated with a diuretic medication (like thiazides or furosemide) for hypertension. These men are usually also cigarette smokers.
Other less common but more serious causes of polycythemia:
2,3-BPG deficiency is a condition in which the hemoglobin molecule in the red blood cells assumes an abnormal structure, and as a result hemoglobin holds on to oxygen very avidly and is less likely to release it to the tissues. In response to poor oxygen supply to the tissues, the bone marrow increases its production of RBCs to enable adequate oxygen delivery to the body organs.
Certain tumors have a tendency to secrete inappropriately high amounts of Epo, leading to polycythemia. The common Epo-releasing tumors are:
• liver cancer (hepatocellular carcinoma),
• kidney cancer (renal cell carcinoma),
• adrenal adenoma or adenocarcinoma, and
• uterine cancer.
Some of the risk factors for polycythemia include:
• chronic hypoxia;
• long-term cigarette smoking;
• familial and genetic predisposition;
• living in high altitudes (the mountains)
• long-term exposure to carbon monoxide (tunnel workers, car garage attendants, residents of highly polluted cities)
Symptoms of polycythemia can vary widely. They could range from no symptoms whatsoever, to a congregation of symptoms like:
• easy bruising;
• easy bleeding;
• blood clot formation (potentially leading to heart attacks, strokes, blood clots in the lungs [pulmonary embolism]);
• bone and joint pain (hip pain or rib pain);
• headache;
• itching;
• itching after taking a shower or bath (post-bath pruritus);
• fatigue;
• dizziness; and
• abdominal pain.
Primary polycythemia has potentially serious complications, such as formation of blood clots (heart attacks, strokes, blood clots in the lungs [pulmonary embolism] or legs [deep vein thrombosis]) and uncontrolled hemorrhaging (nosebleeds, gastrointestinal bleeding). As such, it cannot be overlooked and needs prompt medical attention. Secondary polycythemia can be managed by elimination of the underlying cause(s).
Most cases of polycythemia are detected incidentally on routine blood tests. A comprehensive medical history, physical examination, and social and occupational history are key to making the diagnosis. If an enlarged spleen (splenomegaly) is felt on physical exam, polycythemia vera should be ruled out.
Routine blood work including a compete blood count (CBC), clotting profile, and metabolic panel are basic components of laboratory tests in assessing the cause of polycythemia. Other typical tests to determine the potential causes of polycythemia include chest X-rays, electrocardiogram (ECG), echocardiogram, hemoglobin analysis, and carbon monoxide measurement.
In polycythemia vera, bone marrow examination (bone marrow aspiration or biopsy) can be necessary to assess blood cell production. JAK2 gene mutation is also recommended as a diagnostic criterion for polycythemia vera. Checking Epo levels are not required, but these can sometimes provide helpful information.
Secondary polycythemia, as previously indicated, is treated my addressing the underlying condition. So for example, if you have COPD, oxygen supply will help, in addition to smoking cessation of course. If you are on diuretics, increasing water intake, dose adjustments or changing your meds by your doctor may be necessary.
First line treatment for polycythemia vera remains phlebotomy (blood letting), which aims to maintain the hematocrit around 45% in men and 42% in women. The frequency of phlebotomy may be initially every 2-3 days to take out 250-500 mL of blood each session. Once the goal is reached, maintenance phlebotomy can be performed less frequently.
Another treatment option is a drug called hydroxyurea (Hydrea), especially useful in people at risk of clot formation. Aspirin has also been used in treating polycythemia to lower the risk of clotting (thrombotic) events. Its use is not advised in individuals with any bleeding tendency. Aspirin is usually used in conjunction with phlebotomy.
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this conditioncalled polycthemia vera wherered red cells hemoglobulin hematocrit are elevated tratment is phlebotomy and asp
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