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654 Part VI: The Erythrocyte Chapter 44: Anemia Resulting From Other Nutritional Deficiencies 655

SELENIUM DEFICIENCY An abrupt fall in hemoglobin following protein feeding may be an
Selenium deficiency occurs in patients who live in areas where the sele- ominous harbinger of an adverse and even fatal outcome and prompt
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nium content of the soil is very low and has been observed in patients transfusion to restore hemoglobin may be life-saving. It has been sug-
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receiving total parenteral nutrition. 75,76 Although this results in a strik- gested that erythroblastic aplasia may be a manifestation of riboflavin
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ing decrease in the level of red cell glutathione peroxidase, there do not deficiency.
appear to be any adverse hematologic consequences. Although plasma volume is reduced to a variable degree in chil-
An examination of the relationship between serum selenium and dren with kwashiorkor, total circulating red cell volume decreases in
hematologic indices found that low serum selenium was independently proportion to a decrease in lean body mass as protein deprivation
associated with anemia among older men and women in the United reduces metabolic demands. During repletion, an increase in plasma
States. A similar association has been reported in adolescent girls liv- volume may occur before an increase in red cell volume, and anemia
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ing in rural Vietnam. 78 may seem to become more severe despite reticulocytosis. In a report
from Turkey of patients with protein-energy malnutrition, the major
cause of anemia was identified as associated with either iron deficiency
ANEMIA OF STARVATION or defective utilization of iron. 89
From study of anemia of protein deficiency in rats, it was deduced
Studies conducted during World War II among prisoners of war and that oxygen consumption and, therefore, erythropoietin production
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conscientious objectors demonstrated that semistarvation for 24 weeks are reduced. Other studies confirmed this observation but related the
can result in a mild to moderate normocytic normochromic ane- reduction to calorie deprivation with associated decrease in blood levels
mia. Marrow cellularity is usually reduced and is accompanied by a of triiodothyronine (T ) and thyroxine (T ). As a result, erythropoie-
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4
3
decreased erythroid-to-myeloid ratio. Measurements of red cell volume sis decreases and reticulocyte count falls. Plasma iron turnover and red
and plasma volume suggest that dilution is a major factor responsible cell uptake of radioactive iron are markedly reduced, and red cell vol-
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for a reduction in hemoglobin concentration. ume gradually declines. Protein deficiency also produces a maturation
In persons subjected to complete starvation, either for experimen- block at the erythroblast level and slight decrease in the erythropoietin-
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tal purposes or treatment of severe obesity, anemia was not observed sensitive progenitor cell pool. If exogenous erythropoietin is provided,
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during the first 2 to 9 weeks of fasting. Starvation for 9 to 17 weeks normal erythropoiesis is restored despite protein depletion, an obser-
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produced a decrease in hemoglobin and marrow hypocellularity. vation that explains the successful use of starved rats in a bioassay for
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Resumption of a normal diet was accompanied by reticulocytosis and erythropoietin.
the disappearance of anemia. It has been suggested that the anemia Anemia seen in anorexia nervosa shows some features that resem-
of starvation is a response to a hypometabolic state with its attendant ble protein energy malnutrition. Anemia and leukopenia are found in
decrease in oxygen requirements. 82 approximately one-third of patients, and 50 percent of these show mar-
row atrophy with gelatinous transformation of the marrow stroma. 93
ANEMIA OF PROTEIN DEFICIENCY ALCOHOLISM
(KWASHIORKOR)
Chronic alcohol ingestion is often associated with anemia. This anemia
Even strict vegetarians do not seem to develop hematologic problems may result from nutritional deficiencies, chronic gastrointestinal bleed-
related to the absence of animal proteins. Vegans may, however, ing, hepatic dysfunction, or direct toxic effects of alcohol on erythro-
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develop vitamin B deficiency. The anemia in this situation is caused poiesis. Quite commonly, all these factors work in concert to produce
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by cobalamin insufficiency rather than animal protein insufficiency, and anemia. Pyridoxal phosphate and folate deficiency are common in alco-
results from the natural occurrence of cobalamin exclusively in foods of holics. Alcohol affects not only red cells, as described here, but also
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animal origin. Kwashiorkor is largely a disease of the underdeveloped platelet production (Chap. 113). 95,96
world, but occasionally is seen even among the children of educated and Macrocytosis is common in chronic alcoholics and is often asso-
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well-to-do parents when the children are fed an inappropriate diet. 85,86 ciated with megaloblastic anemia. Among hospitalized malnourished
In infants and children with protein-calorie malnutrition, hemo- alcoholics, it is the most common type of anemia, occurring alone or
globin concentration may fall to 8 g/dL of blood, 86,87 but some children in combination with ringed sideroblasts in approximately 40 percent
with kwashiorkor have normal hemoglobin levels, probably because of of patients. 98,99 In contrast, megaloblastic anemia is rarely observed in
a decreased plasma volume. The anemia is normocytic and normochro- nonhospitalized chronic alcoholics or relatively well-nourished sub-
mic, but the size and shape of red cells on blood film vary considerably. jects admitted to the hospital for alcohol withdrawal. Anemia, when
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White blood cells and platelets are usually normal. Marrow is cellular associated with megaloblastic marrow changes in alcoholics, almost
or slightly hypocellular, with a reduced erythroid-to-myeloid ratio. Ery- always results from folate deficiency. Iron deficiency often is associated
throblastopenia, reticulocytopenia, and marrow containing a few giant with folate deficiency in alcoholics. In patients with both nutritional
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pronormoblasts may be found, particularly if the child has an infection. deficiencies, the blood film is “dimorphic,” with macrocytes, hyperseg-
With treatment of the infection, erythroid precursors may appear in the mented neutrophils, and hypochromic microcytes. This is also the case
marrow, and reticulocyte count may rise. When nutrition is improved when folate deficiency coexists with a sideroblastic process. 98,99 Conse-
by giving high-protein diets (powdered milk or essential amino acids), quently, the MCV may be normal but, because of marked anisopoiki-
reticulocytosis, a slight fall in hematocrit because of hemodilution, and locytosis, the red cell distribution width (RDW) is elevated. Although
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then rises in hemoglobin level occurs. Improvement is very slow, how- liver disease is frequently present in alcoholics with megaloblastic ane-
ever, and during the third or fourth week, when patients are clinically mia, it is not responsible for the folate deficiency. Megaloblastic anemia
improved and serum protein levels are approaching normal, another occurs almost exclusively in alcoholics who have been eating poorly. It
episode of erythroid marrow aplasia may develop. This relapse is not is seen more commonly in heavy drinkers of wine and whiskey, which
associated with infection, does not respond to antibiotics, and does not contain little or no folate, than in drinkers of beer, which is a rich source
remit spontaneously. It may respond to either riboflavin or prednisone. of the vitamin.

Kaushansky_chapter 44_p0651-0656.indd 654 9/17/15 6:30 PM