Paroxysmal nocturnal hemoglobinuria with onset in childhood and adolescence

Article Abstract:

Blood plasma contains, among other things, a system of proteins called complement. The complement chain helps protect the body against foreign organisms, and can literally punch holes in the cell membranes of invading microorganisms. In some patients, however, complement occasionally punches holes in the patient's own red blood cells. This lead to the release of large amounts of hemoglobin. Most of this red protein ends up in the urine, and the condition is, in fact, called paroxysmal nocturnal hemoglobinuria (PNH). The defect in this condition seems to be in the stem cells in the bone marrow. Stem cells give rise to the blood cells that mature and ultimately circulate in the blood stream. For some reason, the stem cell defect results in red blood cells that are extraordinarily sensitive to the effects of complement. The presence of this defect in the bone marrow puts patients with PNH at high risk for bone marrow failure. Paroxysmal nocturnal hemoglobinuria usually begins in adulthood, and little has been recorded about the course of the disorder in children and adolescents. For this reason, a study was conducted of 26 patients with indications of PNH starting before the age of 21 years. The features of the disease appear to be different for younger patients. While hemoglobin in the urine is the first symptom that causes half of adult patients to seek medical attention, among the younger patients it was the presenting symptom in only 15 percent of the cases. Conversely, 58 percent of the younger patients presented with signs of bone marrow failure, in contrast with about 25 percent of adults. Eight of the younger patients in the present study have died; about half the patients have survived 13.5 years or more after diagnosis. Bone marrow failure seems to be more common among the patients who were under 21 years when they began to experience symptoms; these patients may be good candidates for bone marrow transplantation. (Consumer Summary produced by Reliance Medical Information, Inc.)

Risk factors, Prognosis, Demographic aspects, Hemoglobinopathy, Hemoglobinopathies, Pure red cell aplasia

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Effect of serum parathyroid hormone and bone marrow fibrosis on the response to erythropoietin in uremia

Article Abstract:

Increased blood levels of parathyroid hormone and bone marrow fibrosis - a proliferation of fibrous connective tissue in the bone marrow - may increase the dosage of erythropoietin required by patients with anemia as a complication of chronic kidney failure. Erythropoietin is used to increase red blood cell production in some patients suffering from anemia. Among 18 patients with chronic kidney failure who were treated with erythropoietin over a one- to three-year period, seven responded poorly to treatment and 11 responded well to treatment. The average dosage of erythropoietin required by patients who responded poorly to treatment was approximately three times higher than that required by patients who responded well to treatment. Patients who responded poorly to treatment were more likely to have increased blood levels of parathyroid hormone and bone marrow fibrosis than those who responded well to treatment.

Health aspects, Complications and side effects, Physiological aspects, Erythropoietin, Chronic kidney failure, Hyperparathyroidism, Fibrosis

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Benign paroxysmal positional vertigo

Article Abstract:

Benign paroxysmal positional vertigo is dizziness caused by movements of the head. It is often caused by small particles in the inner ear, specifically in the semicircular canals. The condition can be diagnosed by moving the patient's head in various positions. This is also the most common treatment for the condition, because moving the head causes the particles to move to a position where they will not cause symptoms. This treatment, called Epley's maneuver, is described.

Care and treatment, Vertigo

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