Lymphocyte subpopulation abnormalities in sickle cell anemia: a distinctive pattern from that of AIDS

In this study, we evaluated lymphocyte subpopulations in 23 adults with SCA. When compared to controls, SCA patients had higher lymphocyte counts with normal numbers of T101+ cells (T-lymphocytes) and T4+ cells. T8+ cells were significantly increased in SCA patients in comparison to controls (1684 +/- 243 vs 980 +/- 367, p less than .001). This increment was largely dependent on a T101-, T8+ cell population. The SCA patients as a group had significantly decreased T4/T8 ratio (p less than .0001). The SCA patients with history of blood transfusions had higher T4+ cells numbers and higher T4/T8 ratio, but no other significant differences from nontransfused patients were noted. Our results are different from those reported for nontransfused children with SCA who showed normal T4/T8 ratio. Thus, a distinct pattern of abnormalities is seen in the lymphocyte subpopulations of adult SCA patients, unrelated to their exposure to blood transfusions.

Impaired IgM antibody responses to an influenza virus vaccine in adults with sickle cell anemia

Type-specific IgM and IgG antibody responses to a polyvalent influenza vaccine were evaluated in 16 adults with sickle cell anemia, with the use of an enzyme-linked immunosorbent assay. When compared to healthy controls, 8 out of the 16 patients had decreased or undetectable postvaccination anti-influenza IgM antibody levels. These patients were found to have significantly lower serum IgM levels and nondetectable splenic tissue (by 99Tc scans), as compared to those with normal IgM responses. Impaired IgM antibody primary immune responses may play a role in the pathogenesis of infectious complications seen in adult patients with sickle cell anemia.

Effect of zinc supplementation on hyperprolactinaemia in uraemic men

Zinc and prolactin levels were measured in 32 male haemodialysis patients; 12 were receiving 50 mg zinc per day as zinc acetate and 20 were not. Zinc-treated patients had significantly higher plasma zinc levels (134 +/- 10 micrograms/dl v 88 +/- 2 micrograms/dl) and lower serum prolactin levels (11 +/- 4 ng/ml v 29 +/- 7 ng/ml) than untreated patients. Plasma zinc and serum prolactin were inversely related in zinc-treated and untreated patients (r = -0.79, p less than 0.001).

Clinical and biochemical manifestation zinc deficiency in human subjects

During the past two decades, essentiality of zinc for man has been established. Deficiency of zinc in man attributable to nutritional factors and several diseased states has been recognized. High phytate content of cereal proteins decreases availability of zinc, thus the prevalence of zinc deficiency is likely to be high in the population subsisting on cereal proteins mainly. Zinc deficiency has been noted to occur in patients with malabsorption syndrome, chronic renal disease, cirrhosis of the liver, sickle cell disease, AE, and other chronically debilitating diseases. Growth retardation, male hypogonadism, skin changes, poor appetite, mental lethargy and delayed wound healing are some of the manifestations of chronically zinc-deficient human subjects. In severely zinc-deficient patients, dermatological manifestations, diarrhea, alopecia, mental disturbances and intercurrent infections predominate. If untreated, the condition becomes fatal. Zinc deficiency affects testicular functions adversely in man and animals. This effect of zinc is at the end-organ level. It appears that zinc is essential for spermatogenesis. Zinc is involved in many biochemical functions. Several zinc metalloenzymes have been recognized in the past decade. Zinc is required for each step of cell cycle in microorganisms and is essential for DNA synthesis. The effect of zinc on protein synthesis may be attributable to its vital role in nucleic acid metabolism. The activities of many zinc-dependent enzymes have been shown to be affected adversely in zinc-deficient tissues. Zinc atoms in some of the enzyme molecules participate in catalysis and also appear to be essential for maintenance of structure of apoenzymes. Zinc also plays a role in stabilization of biomembrane structure and polynucleotide confirmation.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical, endocrinological and biochemical effects of zinc deficiency

The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal disease, certain diuretics, the use of chelating agents such as penicillamine for Wilson's disease, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. The requirement of zinc is increased in pregnancy and during the growing age period. The clinical manifestations in severe cases of zinc deficiency included bullous-pustular dermatitis, alopecia, diarrhoea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males and it is fatal if untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss and hyperammonaemia. Zinc is a growth factor. As a result of its deficiency, growth is affected adversely in many animal species and in man. Inasmuch as zinc is needed for protein and DNA synthesis and cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level and the hypothalamic--pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in a cell division, its deficiency may adversely affect testicular size and thus its function. In mice, the incidence of degenerate oocytes, and hypohaploidy and hyperhaploidy in metaphase II oocytes were increased due to zinc deficiency. Zinc at physiological concentrations reduced prolactin secretion from the pituitary in vitro and it has been suggested that this trace element may have a role in the in vivo regulation of prolactin release. Thymopoietin, a hormone needed for T-cell maturation, has also been shown to be zinc dependent. It is clear that zinc may have several roles in biochemical and hormonal functions of various endocrine organs. Future research in this area is very much needed.

Clinical manifestations of zinc deficiency

The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present. Thymopoeitin, a hormone needed for T-cell maturation, has also been shown to be zinc dependent. Zinc deficiency affects T-cell functions and chemotaxis adversely. Disorders of cell-mediated immune functions are commonly observed in patients with zinc deficiency. Zinc is beneficial for wound healing in zinc-deficient subjects. In certain zinc-deficient subjects, abnormal taste and abnormal dark adaptation have been noted to reverse with zinc supplementation.

Laboratory diagnosis of zinc deficiency

Zinc status in human subjects is assessed by measurement of zinc in plasma, erythrocytes, neutrophils, lymphocytes, and hair. Available data indicate that zinc in neutrophils and the assay of activity of alkaline phosphatase in neutrophils may be the best tools for the diagnosis of zinc deficiency. Measurement of zinc in the plasma is simple and readily available in many laboratories. Plasma zinc is useful provided the plasma is unhemolyzed and conditions, such as infections, acute stress, myocardial infarction and intravascular hemolysis, are ruled out. Inasmuch as hair and erythrocytes turn over slowly, their zinc levels do not reflect recent changes with respect to zinc status. Other useful parameters for assessment of zinc status include metabolic balance studies, urinary zinc excretion. Cu:Zn ratio, zinc tolerance test, and measurement of activities of zinc-dependent enzymes in suitable biological samples.

Decreased natural killer cell activity in patients with zinc deficiency with sickle cell disease

Zinc deficiency is associated with depression of a number of immune responses. To assess the relationship of zinc and natural killer activity, we studied natural killer activity in adults with sickle cell disease and in two normal volunteers rendered zinc deficient by dietary restriction. Natural killer activity was significantly lower in patients with sickle cell disease and zinc deficiency (5.1 +/- 2.9 lytic units per 10(6) cells) than in controls (11.7 +/- 5.0 lytic units per 10(6) cells). In the two volunteers, natural killer activity declined during zinc restriction and returned to near initial levels with zinc repletion. These results suggest that zinc deficiency is associated with a lowering of natural killer activity.

Clinical and biochemical manifestations of zinc deficiency in human subjects

During the past two decades, essentiality of zinc for man has been established. Deficiency of zinc in man attributable to nutritional factors and several diseased states has been recognized. High phytate content of cereal proteins decreases availability of zinc; thus the prevalence of zinc deficiency is likely to be high in the population subsisting mainly on cereal proteins. Zinc deficiency has been noted to occur in patients with malabsorption syndrome, chronic renal disease, cirrhosis of the liver, sickle cell disease, AE (acrodermatitis enteropathica), and other chronically debilitating diseases. Growth retardation, male hypogonadism, skin changes, poor appetite, mental lethargy, and delayed wound healing are some of the manifestations of chronically zinc-deficient human subjects. In severely zinc-deficient patients, dermatological manifestations, diarrhea, alopecia, mental disturbances, and intercurrent infections predominate. If untreated, the condition becomes fatal. Zinc deficiency affects testicular functions adversely in man and animals. This effect of zinc is at the end-organ level. It appears that zinc is essential for spermatogenesis. Zinc is involved in many biochemical functions. Several zinc metalloenzymes have been recognized in the past decade. Zinc is required for each step of cell cycle in microorganisms and is essential for DNA synthesis. The effect of zinc on protein synthesis may be attributable to its vital role in nucleic acid metabolism. The activities of many zinc-dependent enzymes have been shown to be affected adversely in zinc-deficient tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Interactions of trace elements: clinical significance

We examined interaction of the trace element zinc with copper and lead. In sickle cell anemia, the usual situation is one of mild to moderate zinc deficiency owing to renal loss of zinc. Zinc deficiency seems to produce a mild overburden of copper and an increased ceruloplasmin level, probably by enhancing copper absorption. With zinc therapy, this process is reversed. Pharmacological doses of zinc, when administered in a way to ensure effectiveness (without food) will usually lead to copper deficiency. We have taken advantage of the copper-depleting effect of zinc to design a new therapy for Wilson's disease. Zinc, by inducing intestinal metallothionein, inhibits absorption of copper from food, and inhibits reabsorption of endogenously secreted copper, thereby producing a negative copper balance in Wilson's disease. Once we are certain that zinc blocks accumulation of copper in the liver of Wilson's disease patients, zinc therapy will be available as one approach for treating this fatal disease. The animal literature indicates that zinc protects against lead toxicity when both elements are given orally, no doubt through the intestinal metallothionein mechanism. In preliminary experiments in rats, we have not been able to show that toxicity from lead that arrives into the body through a nonoral route is affected by oral zinc supplements.

Pharmacokinetics and tolerance of intravenous and intramuscular recombinant alpha 2 interferon in patients with malignancies

Fifteen patients with advanced hematopoietic and other malignancies were treated with recombinant DNA produced Alpha 2 Interferon (IFN) (Schering) by intravenous (IV) and intramuscular (IM) routes at weekly intervals in escalating doses from 1 X 10(6) IU to 100 X 10(6) IU in order to determine the tolerance and pharmacokinetics. The most common side effects included fever, chills, myalgia, and arthralgia. At doses of 60 X 10(6) or above, severe but reversible hypotension was observed in five patients receiving interferon by intravenous route. Patients receiving interferon by intramuscular route had fever, chills, and myalgias but did not develop hypotension at the same dosage. Two patients with non-Hodgkin lymphoma showed objective evidence of regression. Our data suggest a biphasic pattern of elimination with terminal half-life ranging from 1.9 to 2.9 hours and peak titer of 16,000 units and under for IV interferon, and terminal half-life of 6 hours with peak titers of 600 units for intramuscular interferon. However, interpatient variability precludes a definite conclusion. Although the areas under the serum concentration vs time curves were similar, the intravenous route provided higher but unsustained levels of interferon than the intramuscular route.

Discovery and importance of zinc in human nutrition

The present explosion in knowledge of zinc has been the result of several factors, the major ones being the recognition of the important role of zinc in human health and diseases, its vital functions in biochemical reactions, and the technological advances that make it feasible to quantitate this essential trace element in biological fluids. Deficiency of zinc in humans due to nutritional factors and several disease states has now been recognized. The high phytate content of cereal proteins is known to decrease the availability of zinc; thus, the prevalence of zinc deficiency is likely to be high in a population consuming large quantities of proteins. Alcoholism, malabsorption, sickle cell anemia, chronic renal disease, and chronically debilitating diseases are now known to be predisposing factors for zinc deficiency. A severe deficiency of zinc such as that seen in patients with acrodermatitis enteropathica may be life-threatening. A spectrum of clinical manifestations ranging from mild to severe degrees has now been recognized in human zinc deficiency states. Zinc appears to be involved in many biological functions including DNA synthesis. Roles for zinc in enzymatic functions, cell membranes, and immunity are now well established.

Zinc supplementation and growth in sickle cell disease

With the use of flameless atomic absorption spectrophotometry, we have devised a technique for measuring zinc in neutrophils. Neutrophil zinc levels in patients with sickle cell anemia correlated significantly with height and weight, and with serum testosterone in men. Such correlations were not seen with zinc levels in plasma or erythrocytes. We also report the beneficial effects of zinc supplementation on longitudinal growth and body weight in 14- to 18-year-old patients with sickle cell anemia. Thus, the neutrophil zinc level is a reliable and sensitive indicator of zinc deficiency in these patients.

Zinc metabolism and taste acuity in renal transplant recipients

To determine the effect of renal transplantation on taste acuity and zinc metabolism, we tested 43 patients with functioning allografts for 2.5 to 96 months. They were tested for taste by the 3-drop stimulus technique. In 30 of them, we determined zinc levels in plasma, hair, and urine. Subnormal plasma and hair zinc, as well as hyperzincuria, was present in all of the 15 patients less than 12 months posttransplant. In contrast, 10 patients who were more than 12 months posttransplant had plasma zinc levels, hair zinc, and urinary zinc excretions in the normal range. Zinc concentrations in plasma and hair of 5 patients who were more than 12 months posttransplant with renal failure, were subnormal and were similar to those in hemodialysis patients. Similarly, taste detection and recognition thresholds for sodium chloride, sucrose, urea, and hydrochloric acid were normal only in patients more than 12 months posttransplant with normal renal function. Plasma zinc, hair zinc, and urinary zinc were not related to prednisone or azathioprine dosage. These results suggest that abnormalities of zinc and taste persist up to 12 months posttransplant and may be related to increased urinary zinc losses.

Determination of ultrafiltrable zinc in plasma by flameless atomic absorption spectrophotometry

Ultrafiltrable zinc can be determined in small volumes of plasma by using Amicon ultrafiltration membrane cones and either flameless atomic absorption spectrophotometry or 65Zn. The ultrafiltration membrane cone is made sufficiently zinc-free by acid washing, followed by rinsing with de-ionized water. Within-run CVs were 12 and 10%, respectively, for the two methods. Matrix effects are compensated for by using standards in solutions with an inorganic matrix that simulates the sample matrix. Results for ultrafiltrable zinc by the two techniques agreed, and agreed with previously published data obtained by different ultrafiltration techniques. The mean (and SD) percentage of plasma zinc that was ultrafiltrable in 12 control subjects was 1.0 (0.5) by AAS and 0.7 (0.3) by 65Zn.

Determination of ultrafiltrable zinc in plasma by flameless atomic absorption spectrophotometry

Ultrafiltrable zinc can be determined in small volumes of plasma by using Amicon ultrafiltration membrane cones and either flameless atomic absorption spectrophotometry or 65Zn. The ultrafiltration membrane cone is made sufficiently zinc-free by acid washing, followed by rinsing with de-ionized water. Within-run CVs were 12 and 10%, respectively, for the two methods. Matrix effects are compensated for by using standards in solutions with an inorganic matrix that simulates the sample matrix. Results for ultrafiltrable zinc by the two techniques agreed, and agreed with previously published data obtained by different ultrafiltration techniques. The mean (and SD) percentage of plasma zinc that was ultrafiltrable in 12 control subjects was 1.0 (0.5) by AAS and 0.7 (0.3) by 65Zn.

The role of zinc in gastrointestinal and liver disease

Zinc is essential for many metabolic and enzymatic functions in man. Deficiency of zinc in man has now been recognized to occur not only as a result of nutritional factors, but also in various disease states, including malabsorption syndromes, acrodermatitis enteropathica, Crohn's disease, alcoholism and cirrhosis of the liver. The deficiency state in human subjects exists as a spectrum extending from mild to severe degree. The clinical manifestations of mild zinc deficiency include oligospermia, weight loss and hyperammonaemia. Moderate zinc deficiency is characterized clinically by growth retardation, hypogonadism in males, skin changes, poor appetite, mental lethargy, delayed wound healing, taste abnormalities and abnormal dark adaptation. In severe zinc deficiency states, bullous-pustular dermatitis, alopecia, diarrhoea, emotional disorders, weight loss, intercurrent infections, hypogonadism in males and, if unrecognized, death have been observed. Zinc is needed for the functions of over 100 enzymes. It is essential for DNA, RNA and protein synthesis and, as such, is important for cell division. Zinc is an inducer of mRNA of metallothionein, a protein which may have an important role in the regulation of intestinal zinc absorption. Zinc has a specific effect on testes in animals and man. Recent reports indicate that in human subjects thymopoietin may be zinc dependent and in animal studies somatomedin may be affected adversely due to dietary zinc restriction. Zinc plays an important role in the protection of cell membrane integrity and may be protective against free radical injury. Zinc is known to compete with cadmium, lead, copper, iron and calcium for similar binding sites. In the future, a potential use of zinc may be to alleviate toxic effects of cadmium and lead in human subjects. Recent evidence suggests that thymic-dependent lymphocytes (T cells are zinc dependent. T-helper and suppressor cells, T-effector cells and T-natural killer cells appear to be zinc dependent. Zinc is also essential for some of the neutrophil functions. Thus, it appears that zinc may play an important role in immunity. One may suggest that some of the clinical features of cirrhosis of the liver, such as testicular atrophy, loss of body hair, night blindness, poor wound healing, poor appetite, susceptibility to infections and enhanced sensitivity to drugs, may be related to conditioned deficiency of zinc, future studies are required to determine whether or not zinc supplementation is beneficial to these patients.

Oral zinc therapy for Wilson's disease

Wilson's disease is an inherited disorder of copper accumulation that is fatal if untreated. Because penicillamine, the established treatment, is toxic in a substantial number of patients, we studied the efficacy of zinc treatment. We induced a negative or neutral copper balance in five out of five patients with Wilson's disease who were receiving no therapy other than zinc. Zinc acetate was given every 4 hours during the day, and the patient was not allowed to eat for 1 hour before and 1 hour after each dose. Oral zinc therapy, used according to our regimen, may now be considered in the treatment of patients with penicillamine intolerance. However, it is premature to convert patients to zinc therapy if they tolerate penicillamine well. The efficacy of zinc therapy in the initial removal of the copper burden in acutely ill patients with Wilson's disease has not yet been evaluated.

Essential thrombocythemia: a clonal disorder of hematopoietic stem cell

We studied 5 patients with essential thrombocythemia utilizing glucose-6-phosphate dehydrogenase (G-6-PD) enzyme as a cell marker for determining clonality. One of the patients was found to be heterozygous for isoenzymes B and A in the nonhaemopoietic tissues such as fibroblasts, but manifested only isoenzyme type B in the erythrocytes, neutrophils, and platelets. Our studies support the concept that essential thrombocythemia is a clonal disorder arising in a multipotent stem cell.