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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The high incidence of megaloblastic anemia observed at our institution (2.1% of hospital admissions) prompted us to analyze the causes of cobalamin and/or folate deficiency in 30 patients admitted during the period 1983-1991 to the Medical Department of Locarno District Hospital. The study population includes 19 women and 11 men with a mean age of 69 years (range 28-91 years). All patients had severe macrocytic anemia (mean hemoglobin 74 +/- 23 g/l, MCV 121 +/- 12 fl), striking megaloblastic changes in aspirated marrow, and an elevated serum level of LDH (2170 +/- 2150 U/l). 19 patients had associated thrombocytopenia, 12 leukopenia and 11 both thrombocytopenia and leukopenia. Treatment led to prompt reticulocytosis and correction of megaloblastic changes in all patients, as well as to nearly complete resolution of the neurologic disorder in a patient with severe spastic ataxia. In 15 patients, megaloblastic anemia was caused by folate deficiency related to alcoholism (n = 6, mean age 55 years) and old age or poverty (n = 9, mean age 73 years). Cobalamin deficiency was present in 9 patients (mean age 69 years); it was due to pernicious anemia in 6 patients and to malabsorption in 2, while the cause remained unexplained in 1. The last patients (mean age 76 years) had deficiency of both cobalamin and folate, related to alcoholism (n = 3) or poverty (n = 3).
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PMID:[Megaloblastic anemia: 30 cases in a district hospital]. 787 99

Imerslund-Najman-Grasbeck disease is a rare inherited megaloblastic anaemia secondary to a selective malabsorption of vitamin B12 by ileal enterocytes. The authors report on a 4 year-old tunisian girl who presented as visceral infantile leishmaniasis because of huge splenomegaly and major anaemia. The diagnosis of Imerslund disease was performed on the basis of the association of typical megaloblastic cells in the marrow, permanent proteinuria and favourable outcome under parenteral B12 administration. In addition, ther were no folate deficiency, no anti-intrinsic factor antibodies and no intrinsic factor deficiency. The outcome of the disease is always favourable if parenteral administration of vitamin B12 maintained.
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PMID:[Imerslund-Najman-Grasbeck anemia. Apropos of a case]. 801 68

The literature on folate related neuropathy has been reviewed. Twenty patients fulfilled the following criteria (a) they presented with neurological findings for which no other cause could be found (b) the serum or red cell and/or the CSF folate was low (c) the serum vitamin B12 or vitamin B12 absorption was normal and (d) they showed a significant response to folic acid. Ten presented with a peripheral neuropathy, eight with subacute combined degeneration of the cord and two with a myelopathy. In two patients the neuropathy occurred when treatment for congenital malabsorption of folate--an isolated lesion affecting folate alone--lapsed. Two patients with subacute combined degeneration died and posterio-lateral sclerosis of the cord was confirmed at autopsy. Three patients were mentally retarded and nine showed mental changes which also responded to folate in addition to the neurological disorder. A single biochemical reaction, the methionine synthetase reaction, is suggested as the basis for the neurological as well as the haematological consequences of both vitamin B12 and folate deficiency. The pitfalls in diagnosis are discussed and a greater awareness of the condition urged.
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PMID:Folate responsive neuropathy. 817 46

We prospectively studied 41 consecutive elderly patients with serum cobalamin (vitamin B12) levels lower than 125 pmol/l. The protein-bound cobalamin absorption test (PBAT) was performed in 34 of them and in 27 selected elderly control patients. The lower decision limit was 0.18% and an abnormal test was detected in only 9 (26%) of the 34 patients with low serum cobalamin level. When the PBAT was compared to the Schilling (Dicopac method) test, a concordant result was found in 80%. Serum methylmalonic acid and/or total homocysteine concentrations were elevated in 75% (26/35) of the patients with low serum cobalamin levels but also in 30% (5/17) of the control patients. Of the 12 and 9 cobalamin-deficient patients with elevated serum levels of methylmalonic acid and homocysteine, normalization after cobalamin therapy was obtained in 11 and 5 respectively. In conclusion, determination of serum metabolites and their response to cobalamin therapy are a sensitive index of significant cobalamin deficiency and a useful means of distinguishing between cobalamin and folate deficiency. The PBAT offers little advantage over the Schilling test in diagnosing cobalamin malabsorption in elderly patients.
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PMID:Cobalamin absorption and serum homocysteine and methylmalonic acid in elderly subjects with low serum cobalamin. 834 41

Elderly persons are more likely to have low values for serum and erythrocyte folate, and for serum cobalamin. Many of those with low vitamin levels have biochemical abnormalities consistent with true deficiency, including increased formiminoglutamic acid excretion, abnormal marrow deoxyuridine suppression, and raised serum levels of methylmalonic acid and homocysteine. Therapy with the appropriate vitamin reverses the biochemical defect. Despite this, the clinical consequences for most elderly persons are remarkably few. True megaloblastic anaemia is rare, and the small number of therapeutic trials to date have not improved the levels of haemoglobin in the treated subjects, although the mean corpuscular volume has decreased significantly. There has been recent concern that these low blood vitamin levels might be important causes of nervous system damage, but studies specifically of the elderly have not demonstrated overall improvements in neurological function following therapy. Vascular damage from high blood homocysteine levels secondary to cobalamin or folate deficiency remains a potential hazard. Dietary insufficiency, malabsorption of protein-bound vitamin B12 secondary to atrophic gastritis, and defective absorption of folyl polyglutamates seem the likeliest possible causes. Pernicious anaemia, although a common cause of severe megaloblastic anaemia in the elderly, is an infrequent cause for the low cobalamin levels in population studies. Although the benefits are uncertain, the balance of the evidence suggests that one should treat elderly persons with low values of cobalamin or folate. Crystalline vitamin B12 and folic acid are absorbed normally and are therefore suitable for replacement therapy, provided that pernicious anaemia is excluded.
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PMID:Cobalamin and folate deficiency in the elderly. 853 67

A 43-year-old woman developed abdominal pain and diarrhea following a travel to Malaysia. Examinations in another hospital proved no evidence of infection, an empirical antibiotic therapy with ciprofloxacin yielded no benefit. One and a half year later, the patient was admitted to our department because of persistent diarrhea and wasting. Laboratory tests showed megaloblastic anemia, folate deficiency and steatorrhea. Stool specimens for bacterial pathogens and parasites were negative. Endoscopy and biopsy from the distal portion of the duodenum revealed broadening and shortening of the villi and an increased infiltration of the lamina propria by chronic inflammatory cells (plasma cells and lymphocytes). In conclusion, diagnosis of tropical sprue was established. The therapy comprised of tetracycline for six weeks and folic acid for six months. Subsequently, the diarrhea disappeared, the patient continuously gained weight and was free of any complaints. The complete remission following this regimen proved the suspected diagnosis. Differential diagnosis in any patient who recently returned from the tropics may be a challenge. Tropical sprue predominantly occurs during or after a longer stay in endemic areas. However, if chronic diarrhea and signs of malabsorption develop after a short journey to India, South-East Asia and parts of the Caribbean, tropical sprue has to be considered, too.
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PMID:[Tropical sprue as the cause of chronic diarrhea after travel to Southeast Asia]. 984 68

Several fundamental questions relating to the biochemical basis of megaloblastic hemopoiesis in vitamin B12 (B12) and folate deficiency and neurological damage in B12 deficiency remain to be answered. Among them is the explanation underlying (1) the failure of B12-deficient animals to develop megaloblastic hemopoiesis despite indirect evidence of impaired thymidylate synthesis and (2) the inverse relationship between the extent of hematologic and neurological damage in B12 deficiency. Diagnostic advances have led to the awareness that many patients with B12 or folate deficiency are hematologically normal and that subtle hematologic or neuropsychiatric manifestations may be found at a fairly early stage of developing B12 deficiency. Studies of the mechanism of absorption of B12 in food have identified the syndrome of food B12 malabsorption in which the degree of B12 deficiency is commonly, although not invariably, mild. Folate intake influences the prevalence of neural tube defects (NTDs) and a suboptimal folate status may be associated with an increased risk for dysplasia and cancer. The latter may be at least partly the result of uracil misincorporation into DNA and consequent DNA strand breaks. Folate status has also been linked to arteriosclerotic vascular disease through its effect on serum homocysteine levels. Uracil misincorporation into DNA and increased serum homocysteine levels may also be found in B12 deficiency. These adverse associations form the basis of a case for improving B12 or folate status in individuals with a mild degree of deficiency. Because inadequate folate intake is relatively common, especially in the elderly and the poor, the fortification of staple foods with folate is currently under active consideration.
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PMID:The wide spectrum and unresolved issues of megaloblastic anemia. 993 May 65

Folate or cobalamin deficiencies are usually detected by hematologic abnormalities, such as a macrocytic megaloblastic anemia, or often milder signs, such as hypersegmented neutrophils. In fact, these vitamin deficiencies may be associated with clinical conditions in which anemia and/or macrocytosis are absent, such as neuropsychiatric disorders and inborn errors of folate or cobalamin metabolism. A battery of sensitive tests, including blood vitamin levels, serum methylmaIonic acid and homocysteine assays, and the deoxyuridine suppression test in the bone marrow, allows for early detection of vitamin deficiency. Additional tests may be included to identify the causes of deficiency, such as the Schilling test using crystalline cyanocobalamin, or a modified Schilling test for showing food cobalamin malabsorption. Strategies for diagnosing a vitamin deficiency differ according to the hematologic and clinical presentations. The deleterious effects (aside from anemia) that arise from cobalamin or folate deficiency and include neurological complications, increased risk of vascular disease due to hyperhomocysteinemia, and increased risk of some types of cancer related to folate deficiency, underscore the importance of making an early diagnosis and instituting treatment with the appropriate vitamin in preventing permanent damage.
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PMID:Modern clinical testing strategies in cobalamin and folate deficiency. 993 May 67

Folate plays a key role in nucleic acid synthesis. As a consequence, the most conspicuous complication of folate deficiency or of derangements of folate metabolism is megaloblastic macrocytic anemia caused by interdiction of normal proliferation of rapidly dividing bone marrow cells. Other rapidly dividing cells, including those in the gastrointestinal tract, may also be affected by the megaloblastic process. This may result in malabsorption. However, there is mounting evidence to indicate that there are other earlier manifestations of folate deficiency or of longstanding suboptimal folate nutrition. Chief among these manifestations of folate deficiency are an increased predisposition to occlusive vascular disease and thrombosis, which have been linked to increased levels of homocysteine found in folate deficiency and abnormal states of folate metabolism. In addition, folate deficiency, previously considered free of neurological consequences, is now known to be associated with disturbances of mood, and even spinal cord syndromes similar to those seen in vitamin B12 deficiency. Finally, there is both experimental and clinical evidence to suggest that folate deficiency may interfere with immunologic status and may be associated with an increased predisposition to neoplasia. Nutritional as well as genetic factors may contribute to these various nonhematological manifestations of folate insufficiency.
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PMID:Folate deficiency beyond megaloblastic anemia: hyperhomocysteinemia and other manifestations of dysfunctional folate status. 993 May 68

Serum vitamin B12 levels are often low in human immunodeficiency virus (HIV)-infected patients. However, only a few patients appear to have actual vitamin B12 deficiency. A low red cell folate level accompanying the low vitamin B12 level makes the presence of vitamin B12 deficiency more likely. Our experience suggests that a low red cell folate level always indicates deficiency, but does not differentiate between vitamin B12 and folate deficiency. The deoxyuridine suppression test and the assay of serum or plasma total homocysteine and/or of methylmalonic acid levels can also be useful in the identification of patients with true vitamin B12 deficiency. HIV-positive patients frequently have absorption disorders, including vitamin B12 malabsorption. However, the correlation between vitamin B12 malabsorption and serum vitamin B12 and plasma homocysteine levels is poor. Abnormalities in vitamin B12-binding proteins, which are often found in HIV-positive patients, may explain many cases of low vitamin B12 levels. Current evidence suggests that low vitamin B12 levels are more common as the HIV disease progresses. The results of vitamin B12 treatment have been disappointing thus far, including the prevention of toxicity induced by azidothymidine. The possible role of vitamin B12 treatment in the long-term survival of HIV-infected patients is at present unknown. However, it is important to identify those patients who have real vitamin B12 deficiency to treat or prevent their hematologic and/or neurological symptoms.
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PMID:Cobalamin deficiency in patients infected with the human immunodeficiency virus. 993 May 70


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