Iron deficiency and dyserythropoiesis

N-picolyl derivatives of Kemp's triamine as potential antitumor agents: a preliminary investigation

Preorganized tripodal ligands such as the N-picolyl derivatives of cis,cis-1,3,5-triamino-cis,cis-1,3,5-trimethylcyclohexane (Kemp's triamine) were prepared as analogues to N,N',N''-tris(2-pyridylmethyl)-cis,cis-1,3,5-triaminocyclohexane (tachpyr) in hopes of enhancing the rate of formation and stability of the metal complexes. A tricyclic bisaminal was formed via the reduction of the Schiff base, while the tri(picolyl) derivative was synthesized via reductive amination of pyridine carboxaldehyde. Their cytotoxicities to the HeLa cell line were evaluated and directly compared to tachpyr and N,N',N''-tris(2-pyridylmethyl)tris(2-aminoethyl)amine (trenpyr). Results indicate that N,N',N''-tris(2-pyridylmethyl)-cis,cis-1,3,5-triamino-cis,cis-1,3,5-trimethylcyclohexane (Kemp's pyr) exhibits cytotoxic activity against the HeLa cancer cell line comparable to tachpyr (IC50 approximately 8.0 microM). Both Kemp's pyr and tachpyr show higher cytotoxic activity over the aliphatic analogue of trenpyr (IC50 approximately 14 microM), suggesting that the major contributor to the activity is the ligand's ability to form a stable and tight complex and that the equatorial/axial equilibrium impacting the complex formation for the cyclohexane-based ligands is not significant.

Temporary dysplastic hematological features due to iron deficiency in a case of Poland syndrome

Poland syndrome has been sporadically associated with hematological conditions, primarily acute leukemias. The authors report a child with this syndrome coexisting with temporary hematological dysplasia due to iron deficiency. Further hematological evaluation failed to demonstrate malignancy. Because of its premalignant nature, in patients with Poland syndrome, hematological dysplastic features should be an indication for further investigation. However, in addition to the well-known hematological malignancies, treatable causes may be responsible.

Incidence of high erythrocyte count in infants and young children with iron deficiency anemia: re-evaluation of an old parameter

PURPOSE

To investigate the frequency of high erythrocyte count (red blood cell count >or=5.0 x 106/microL) in infants and young children with iron deficiency anemia and to document the differences in hematologic parameters at diagnosis and during iron therapy in IDA patients with and without a high erythrocyte count.

PATIENTS AND METHODS

A total of 140 infants and young children aged 6 to 48 months with nutritional IDA without a history of any bleeding disorder were the subjects of this study. The patients were divided into three groups according to the severity of anemia. Group A1 children had Hb values 8.0 g/dL or less (severe anemia); group A2, 8.1 to 10.0 g/dL (moderate anemia); and group A3, 10.1-11.0 g/dL (mild anemia). All children received oral iron (3-5 mg/kg per day) for 12 weeks. Complete blood counts were done weekly during treatment.

RESULTS

A total of 36 of the 140 patients (26%) had a high erythrocyte count. Of the 140 patients, 37 were in group A1, 80 in A2, and 23 in A3. The frequency of high erythrocyte count was 11%, 23%, and 61% in groups A1, A2, and A3, respectively. The patients with a high erythrocyte count had significantly higher Hb and Hct but significantly lower mean corpuscular volume and mean corpuscular hemoglobin (MCH) values than those with a low erythrocyte count (n = 104). A continuous elevation in the erythrocyte count has been observed in patients with a high red cell count, as in those with a low red cell count, after the institution of iron therapy.

CONCLUSIONS

A high erythrocyte count is a common feature of iron deficiency anemia in infants and young children, with an increasing frequency from severe to moderate to mild anemia. High erythrocyte count cannot be regarded as a reliable preliminary parameter in differentiating iron deficiency from thalassemias in infants and children aged up to 48 months.

Dyserythropoiesis in iron-deficiency anemia: ultrastructural reassessment

Iron deficiency is usually included among the causes of acquired dyserythropoiesis. This concept was derived mainly from light microscopic studies. To reassess such a notion at ultrastructural level, a transmission electron microscopic evaluation of bone marrow was performed in seven patients with iron-deficiency anemia. In contrast to the widely accepted concept, derived from light microscopic studies, only a small proportion (2-4%, not different from controls) of erythroblasts displayed some of the features of nuclear dyserythropoiesis. On the contrary, when examining the cytoplasm, we found a significantly increased number of void ropheocytotic vesicles in the majority of late erythroblasts as compared to controls (P less than 0.001). This feature may be considered as an ultrastructural marker of iron deficiency and is consistent with the present knowledge on transferrin-mediated delivery of iron to the cell.

Acquired iron-deficiency anaemia due to impaired iron transport

A previously healthy 39-year-old woman presented with severe iron-deficiency anaemia, but she had lost no blood and her serum iron level was high. Her bone marrow was hypercellular with a predominance of erythroid elements and had no stainable iron deposits, but it also showed dyserythropoiesis and an excess of apparently normal plasma cells. IgM was demonstrated on her bone-marrow erythrocytes and their precursors. On azathioprine and prednisone therapy she had a complete clinical and haematological remission. The impaired iron transport and the associated dyserythropoiesis were probably due to an IgM-mediated autoimmune process. Diabetes mellitus, which first appeared during her anaemic illness, could also have been due to an autoimmune process. This is the first report of an iron-deficiency anaemia caused by a naturally acquired impairment of iron transport.

Bone marrow and peripheral blood globin chain biosynthesis in iron deficiency

Globin chain synthesis was studied in 13 iron-deficient patients. The mean whole-cell globin alpha/beta ratio in the peripheral blood of 11 patients was 1.05 +/- 0.06 which is similar to the value 0.99 +/- 0.08 obtained for 10 controls. The ratios obtained for stroma-free globin were not significantly different from those of whole cell preparations. In contrast, the alpha/beta ratio of bone marrow was 0.73 +/- 0.14 in 10 iron deficient patients, which is significantly lower than that of controls. Two other patients had decreased alpha/beta ratios in the peripheral blood, probably because of the presence of an alpha-thalassemia gene. These results demonstrate a reduced rate of synthesis of alpha chains relative to that of beta chains in the bone marrow of iron-deficient patients that is not demonstrable in the peripheral blood.

The laboratory evaluation of microcytic red blood cells

Microcytic red blood cell states are common clinical problems in both adult and pediatric age groups. The recent widespread availability of electronic blood cell counters for performing routine blood counts has increased the detection of microcytic red blood cells. Physicians must workup both symptomatic and asymptomatic patients with microcytic red blood cells before they can initiate proper therapy and/or counseling. The purpose of this review is threefold: (1) to discuss the causes of microcytic red blood cells in terms of disorders of decreased heme production vs. disorders of decreased globin production, (2) to review the clinical laboratory tests useful in differentiating microcytic red blood cell states, and (3) to present a practical approach for the laboratory workup of microcytic red blood cells.

Large basophilic cells in the bone marrow in iron deficiency anemia

Many large cells with a strongly basophilic cytoplasm and large nuclei with a delicate chromatin pattern and large nucleoli were studied in 1 mu sections of core biopsies in 8 patients with iron deficiency anemia and in 5 patients with pernicious anemia. In 2 normal controls these cells were rare. Possible features of granulocytic differentiation were assessed with the Giemsa stain and with the naphtol-ASD-chloroacetate esterase reaction which is indicative of early granule formation: the large cells were constantly negative. In thin sections the morphological appearances of the large basophilic cells are rather similar in such different haematological disorders as pernicious anemia or iron deficiency anemia. A clear difference can be demonstrated by karyometry, which shows that the large basophilic cells in pernicious anemia are significantly larger than those in iron deficiency anemia or in the normal control.

Effect of iron deficiency and desferrioxamine on DNA synthesis in human cells

Desferrioxamine (10(-3) M) caused a fall in the deoxyadenosine triphosphate level after 4 h incubation in normal phytohaemagglutinin-stimulated lymphocytes. There was a rise in the concentrations of the other three deoxyribonucleoside triphosphates (deoxythymidine-,deoxycytidine-and deoxyguanosine-triphosphate). The changes are similar to those caused by hydroxyurea, a known inhibitor of ribonucleotide reductase. Desferrioxamine (10(-3 M) was found to inhibit human lymphocyte ribonucleotide reductase to a mean of 11% of control activity after 45 min incubation. Both drugs, desferrioxamine and hydroxyurea, inhibited incorporation of [3H]thymidine DNA into lymphocytes in the presence or absence of deoxyuridine, and inhibited production of lymphocytic thymidine kinase, having opposite effects to methotrexate on both [3H]thymidine incorporation and thymidine kinase activity. Phytohaemagglutinin-stimulated lymphocytes from patients with chronic iron deficiency showed lower levels of all our deoxyribonucleoside triphosphates than normal lymphocytes. It is suggested that this may be due to reduced ribnucleotide reductase activity of the iron-deficient cells.