Evaluation of Macrocytic Anemias.

Macrocytic anemia, defined as a mean cell volume (MCV) ≥100 fL in adults, has a narrow differential diagnosis that requires evaluation of the peripheral blood smear as well as additional laboratory testing taken in conjunction with clinical information that includes patient history and physical examination findings. This review is an update on the approach to a patient with macrocytic anemia with attention paid to the differentiation of megaloblastic and non-megaloblastic macrocytic anemias. Critical to the determination of the diagnosis is the judicious use of laboratory testing and the evaluation of those findings in conjunction with the patient medical, surgical, and medication history.

Hydroxyurea increases plasma concentrations of microparticles and reduces coagulation activation and fibrinolysis in patients with sickle cell anemia.

Microparticles (MPs) are present in healthy subjects and their concentration increases in patients at high risk of thrombosis. We evaluated 10 patients with sickle cell anemia (SCA) treated with hydroxyurea (HU) and 13 SCA patients without this treatment. MP concentrations were determined by flow cytometry. Coagulation was evaluated using the thrombin-antithrombin complex (TAT) and D-dimers. Total MP concentrations were increased in the HU-treated group (265 × 10(6)/ml vs. 67.45 × 10(6)/ml; p = 0.0026), as well as MPs derived from RBC (67.83 × 10(6)/ml vs. 26.31 × 10(6)/ml; p = 0.05), monocytes (51.31 × 10(6)/ml vs. 9.03 × 10(6)/ml; p = 0.0084), monocytes with tissue factor (TF) expression (2.27 × 10(6)/ml vs. 0.27 × 10(6)/ml; p = 0.0058), endothelium (49.42 × 10(6)/ml vs. 7.23 × 10(6)/ml; p = 0.007) and endothelium with TF (1.42 × 10(6)/ml vs. 0.26 × 10(6)/ml; p = 0.0043). Furthermore, the concentrations of TAT (7.56 vs. 10.98 µg/l; p = 0.014) and D-dimers (0.65 vs. 1.29 µg/ml; p = 0.007) were reduced with HU. The MP elevation may suggest a direct cytotoxic effect of HU. Another explanation is a cell surface increase secondary to a megaloblastic process, resulting in increased vesicle release. In our opinion, the known benefits of HU on SCA patients, along with the reduction in coagulation activation, surpass its potential detrimental effect on MPs. Future studies should elucidate the role of MPs and demonstrate their significance in different contexts.

[Pronounced pancytopenia with concomitant jaundice in a 66-year-old woman]. / Ausgeprägte Trizytopenie mit Ikterus bei einer 66-jährigen Patientin.

HISTORY AND ADMISSION FINDINGS: A previously healthy 66-year-old women presented with onset of general weakness, shortness of breath and significant weight loss. Due to appearance of jaundice, biliary obstruction had been ruled out by a CAT scan previous to the patients presentation in our practice. INVESTIGATIONS: The laboratory tests already arranged by the patients general practitioner showed a pronounced pancytopenia with megaloblastic anemia and hyperbilirubinemia. The bone marrow aspiration revealed a hypercellular bone marrow with megaloblastic erythropoiesis. The diagnosis of pernicious anemia was confirmed by the low cobalamin (vitamin B12) serum level and the presence of atrophic gastritis. TREATMENT: Pernicious anemia was treated with intramuscular injection of Cyanocobalamin (1000 µg) which resulted in an immediate reticulocytosis and a widely normalized blood cell count and bilirubin level four weeks after initiation of treatment. CONCLUSION: The differential diagnosis of megaloblastic anemia covers a wide spectrum of diseases with different etiology. This case report demonstrates an example of a pernicious anemia with atypical and foudroyant clinical course.

Embryo-fetal erythroid megaloblasts in the human coelomic cavity.

The coelomic cavity is part of the extraembryonic mesoderm, surrounding amniotic cavity, embryo, and yolk sac in the early gestation. It is now believed to represent an important transfer interface and a reservoir of nutrients for the embryo. Coelocentesis by ultrasound-guided transvaginal puncture offers an easier access to the early human embryo, from 28 days post-fertilization. However, despite some studies about its biochemical composition being reported, our knowledge about the presence of cellular elements and their quality in this compartment are still limited. Here we studied human coelomic fluids sampled from 6.6 (48 days) to 10 weeks of gestation, demonstrating the presence of functional embryonic erythroid precursors, that is, megaloblasts in the coelomic cavity. The ease of access of the coelomic cavity could allow the development of novel strategies for diagnostic or therapeutic purposes by ultrasound imaging and ultrasound-guided puncture.

Reversible bone marrow dysplasia in patients with systemic lupus erythematosus.

OBJECTIVE: Several reports of bone marrow dysplasia in patients with systemic lupus erythematosus (SLE) have been published. However, the reports are restricted primarily to descriptions of the erythroid lineage; no follow-up studies have been reported, and the clinical significance of the dysplasias is unknown. Therefore, in the present study, the dysplasias noted in bone marrow aspirates obtained from SLE patients were characterized. PATIENTS AND METHODS: The smears of bone marrow aspirates obtained from 17 SLE patients who had bone marrow aspiration due to cytopenia (WBC < 1,500/microl, or Hb < 10.5 g/dl, or platelet count < 10 x 10(4)/microl) were examined retrospectively. Of the 17 patients, 4 had a repeat bone marrow aspiration during follow-up. Clinical and laboratory data were obtained from the medical records. RESULTS: Of the 17 SLE patients, 12 had dysplasias, including: erythroid cell multinuclearity (trinuclear or more) (5 patients), megaloblastoid changes (4), pseudo-Pelger abnormalities (6), annular nuclear myeloid cells (2), separated nuclear megakaryocytes (4), and micromegakaryocytes (5). In the 4 patients who had follow-up bone marrow aspiration, these dysplasias were correlated with disease activity; some abnormalities disappeared with remission of SLE. Diffuse proliferative glomerulonephritis (3 patients) and cerebral lupus/neuropsychiatric lupus (4 patients) were seen only in patients with dysplasia. CONCLUSION: This study found that bone marrow dysplasia can be observed in all lineage cells of SLE patients, and that the dysplasia is reversible during the course of the disease. The presence of dysplasias appears to be associated with disease severity.

DNA ploidy and cell cycle analyses in the bone marrow cells of patients with megaloblastic anemia using laser scanning cytometry.

BACKGROUND: Megaloblastic anemias are characterized by several hematopoietic cells with dysplastic nuclear morphology. The analyses of DNA ploidy and cell cycle of these cells are important to understand the property of such diseases. METHODS: As laser scanning cytometry (LSC) is a useful tool to evaluate the morphology of the cells fixed on the slide glass together with the quantitative analysis of the fluorescence information of each cell by rapid scanning of the specimens, the authors examined the DNA ploidy and cell cycle of six cases with megaloblastic anemia using LSC. RESULTS: Giant neutrophilic series such as giant metamyelocytes and giant band cells were found to have extraordinarily higher DNA ploidy, while hypersegmented neutrophils represented the normal diploid pattern like normal neutrophils. As to megaloblasts, cell cycle analysis showed that the proportion of the cells in S phase was increased as compared with the case of normal erythroblasts. CONCLUSIONS: The present study clearly demonstrates the abnormal aspects of the hematopoietic cells with megaloblastic anemia from the viewpoint of the DNA ploidy and cell cycle analyzed by the use of LSC.

A new disease categorization of low-grade myelodysplastic syndromes based on the expression of cytopenia and dysplasia in one versus more than one lineage improves on the WHO classification.

Multilineage dysplasia was advanced by the World Health Organization to increase prognostic accuracy in myelodysplastic syndromes (MDS) classification. We performed a structured cytomorphological examination of bone marrow (BM) in 221 low-grade MDS patients, this in conjunction with strict guidelines for cytopenias. A dysplasia scoring system was developed utilizing dysplastic changes, which were associated with worse outcome on univariate and multivariate analysis corrected for the International Prognostic Scoring System (IPSS). Dysplasia >or=10% in one BM lineage and one cytopenia constituted the low-risk category UCUD or Unilineage Cytopenia and Unilineage Dysplasia. The high-risk category comprised patients with cytopenia in >or=2 lineages and dysplasia in >or=2 BM lineages, namely MCMD or Multilineage Cytopenia and Multilineage Dysplasia. Intermediate-risk patients had one cytopenia and multilineage dysplasia, or cytopenia in >or=2 lineages and unilineage BM dysplasia, designated UCMD/MCUD or Unilineage Cytopenia and Multilineage Dysplasia/Multilineage Cytopenia and Unilineage Dysplasia. This system utilizing cytopenia-dysplasia scoring at diagnosis enabled comprehensive categorization of low-grade MDS cases that predicted for overall as well as leukemia-free survival. Cytopenia-dysplasia categorization added additional prognostic values to the lower risk IPSS categories. This suggests that a standardized dysplasia scoring system, used in conjunction with cytopenia, could improve diagnostic and prognostic sub-categorization of MDS patients.

Megaloblastosis: from morphos to molecules.

OBJECTIVE: Megaloblastosis (i.e., megaloblastic transformation of erythroid precursor cells in the bone marrow) is the cytomorphological hallmark of megaloblastic anemia resulting from vitamin B12 and folate deficiency. It is characterized by a finely stippled lacy pattern of nuclear chromatin, which is believed to be an expression of deranged cellular DNA synthesis. However, the molecular basis of these cytomorphological aberrations still remains obscure. The current presentation describes the results of our studies on some molecular events associated with the development of megaloblastosis. METHODS: Transmission electron microscopy was used to study megaloblasts as well as DNA fibers extracted from megaloblastic and normoblastic bone marrows with and without treatment with proteinase K during the extraction procedure; cellular DNA synthesis in bone marrow cultures was studied by incorporation of 3H-thymidine and deoxyuridine suppression test, while histone biosynthesis in bone marrow cells was studied by in vitro incorporation of 3H-tryptophan, 3H-lysine and 3H-arginine into histones. RESULTS: Derangement of DNA synthesis occurred due to an impaired de novo pathway of thymidylate synthesis in both vitamin-B12- and folate-deficient human megaloblastic bone marrows as well as in the bone marrows of rhesus monkeys and rats with experimentally induced folate deficiency. Interestingly, folate-deficient monkeys developed frank megaloblastic bone marrows, but folate-deficient rats did not. On the other hand, megaloblastic changes in the bone marrow of human patients with myelodysplastic syndrome and erythroleukemia were not associated with this DNA synthetic abnormality. Biosynthesis of predominantly arginine-rich histones in megaloblastic bone marrows was markedly reduced as compared to normoblastic bone marrows, which was consistently associated with elongation and despiralization of chromosomes and finely stippled nuclear chromatin in megaloblasts. CONCLUSION: The impaired biosynthesis of predominantly arginine-rich nuclear histones appeared to be a common molecular event (a denominator) underlying the development of megaloblastosis with or without abnormal DNA synthesis.

On the pathogenesis of erythroleukaemia (H0493).

In erythroleukaemia megaloblastic changes can co-exist with leukaemic changes in the marrow. The cause of the disease must therefore be such as can cause megaloblastosis and at the same time be mutagenic. Failure of the thymidylate synthelase reaction, the commonest cause of megaloblastic anaemia, can be eliminated in erythroleukaemia because (a) the dU suppression test is normal in the disease and (b) failure of the thymidylate synthelase reaction is not mutagenic. The deamination of both cytosine and adenine is mutagenic but the deamination of cytosine alone is apparent and the nucleotide of cytosine is the prime mutagenic nucleotide in leukaemia and cancer. Megaloblastic changes can result from an inadequate supply of any one of the four nucleotides that enter into the composition of DNA and it is suggested that an inadequate supply of the mutagenic nucleotide of cytosine, possibly through impaired synthesis, could cause both the megaloblastic and leukaemic changes in erythroleukaemia.

Sulfasalazine-induced Megaloblastic Anemia in Normal Serum Folate Level / 대한류마티스학회지

Sulfasalazine produces a varied spectrum of adverse reactions on the hematopoietic system. Sulfasalazine-induced megaloblastic anemia is very rare and a few cases have been reported in patients with inflammatory bowel disease. Most of them show a low serum folate level. The pathogenesis is known as folate deficiency by intestinal folate malabsorption, inhibition of folate enzyme, or hemolysis. We experienced a 43-year old female with Behcet's disease, who presented with megaloblastic anemia having normal serum folate level after treatement of sulfasalazine (2 g/day for 3 months). Megaloblastic anemia recovered after withdrawal of the drug only.

Causes and Clinical Features of Vitamine B12 Deficiency Megaloblastic Anemia / 대한혈액학회지

BACKGROUND: Vitamim B12 deficinecy is not a common disease and the causes and clinical findings were not clearly documented in Korea so far. Concerning that vitamin B12 deficiency caused by gastrectomy is not uncommon, we analysized the causes of vitamin B12 deficiency and clinical findings. METHODS: We reviewed the clinical records of cases diagnosed as vitamine B12 deficiency megaloblastic anemia in Hallym Medical Center from July, 1992 to Octorber, 2004. RESULTS: Forty five cases were included. Twenty five cases were performed gastrectomy and 8 cases had pernicious anemia, however the causes of 10 cases with vitamin B12 deficiency were not clear. The rate of the cases induced by gastrectomy were increased after 2001 compared with the rate before this point. Six cases were combined with iron deficient anemia. In five of the 6 cases who were combined with iron deficient anemia, the MCV and MCH were not increased. Forty three cases had anemia and anemia-associated symptoms such as dyspnea and weakness. Some of the cases complained diarrhea, numbness, or ataxia. CONCLUSION: We found that the gastrectomy was the dominant cause of vitamin B12 deficient megaloblastic anemia in this study. We suggest that vitamin B12 deficient megaloblastic anemia should be considered in follow-up of the cases of gastrectomy.

Two Cases of Megaloblastic Anemia Induced by Vitamin B12 Deficiency in Children / 대한소아혈액종양학회지

Megaloblastic anemia induced by Vitamin B12 deficiency is a disorder caused by impaired DNA synthesis. It has been previously thought to be rare in children, however, recent studies suggest that this condition is more common than previously recognized. Deficiency can lead to a wide spectrum of hematologic and neuropsychiatric disorders. Especially in children, it often presents with nonspecific manifestations, such as developmental delay, irritability, weakness, and failure to thrive. Early diagnosis and prompt treatment might resolve these complications, but permanent neurologic damage may have already occurred. We experienced two cases of Megaloblastic Anemia induced by Vitamin B12 deficiency and report them with a brief review of the literature.

RAEB-t in young adults--a rare entity.

Refractory anemia with excess blasts in transformation (RAEB-t) in young adults is a rare entity. RAEB-t presenting with megaloblastic erythropoiesis should be differentiated from nutritional B12 and folic acid deficiency and from acute erythroleukemia. We report two cases in the present article.

Thiamine-responsive Megaloblastic Anemia Syndrome in a Mother and Five Daughters / 대한소아혈액종양학회지

Thiamine-responsive megaloblastic anemia (TRMA) syndrome is an early-onset autosomal recessive disorder characterized by megaloblastic anemia with ringed sideroblasts, diabetes mellitus and progressive sensorineural deafness, all of which respond in varying degrees to the administration of thiamine, in pharmacologic doses. TRMA syndrome has been reported in less than 30 families, but has never been reported in Korea. It has been demonstrated recently that TRMA is consistently associated with a defect in thiamine transport across cellular membranes and with impaired intracellular pyrophosphorylation. The TRMA syndrome gene, SCL19A2, locates on chromosome 1q23.2-23.3, and encodes a high-affinity thiamine transporter protein. We recently experienced 6 cases of thiamine-responsive megaloblastic anemia syndrome in a family, including a mother and five daughters. All the six cases revealed megaloblastic anemia refractory to vitamin B12 and folic acid therapy but responded to thiamine. We report the cases with a brief review of the literature.

Assessment of the Diagnostic Utility of Methylmalonic Acid in Megaloblastic Anemia due to Vitamin B12 Deficiency / 대한진단검사의학회지

BACKGROUND: Methylmalonic acid (MMA) is one of the metabolites of the DNA synthesis metabolic pathway wherein vitamin B12 acts as a coenzyme. Vitamin B12 deficiency leads to inhibition of methyl-malonyl CoA mutase, and sequential elevation of blood and urine concentrations of MMA. It has been known that the urine concentration of MMA is a more specific and sensitive marker than the hema-tologic indices and the serum concentration of vitamin B12 for the diagnosis of vitamin B12 deficiency. We investigated the sensitivity of urine concentration of MMA and the usefulness as a differential mark-er for myelodysplastic syndrome (MDS) and megaloblastic anemia (MA). METHODS: We identified 37 cases that were examined for both urine concentrations of MMA and bone marrow studies from January 1996 to December 2000. Serum concentrations of vitamin B12 and folate were measured by the chemiluminescence immunoassay using ACS:180 (Bayer Diag-nostics). Urine concentration of MMA was measured by isotope dilution gas chromatography-mass spectrometry (GC 8000-gas chromatography MD800). RESULTS: Of 36 patients, 12 patients were diagnosed with MA, 8 patients with MDS, 5 patients with aplastic anemia based on the bone marrow study. Increased urine concentration of MMA was observed in all the patients with MA, but none of the patients with MDS. Using a cut-off value of 5 mmol/mol creatinine urine concentration MMA, the sensitivity and specificity in diagnosis for MA were 100% and 80%. The correlation between the urine concentration of MMA and the serum con-centration of vitamin B12 was insignificant (r=-0.25, P=0.21). The highest correlation index with urine concentration of MMA was the red cell distribution width (r=0.74, P < 0.01). CONCLUSIONS: We concluded that the urine concentration of MMA was a sensitive marker for diagno-sis of MA caused by vitamin B12 deficiency and could be a useful test in the differentiation for MA from MDS. Although a consensus for a diagnostic value of the urine concentration of MMA would be nec-essary, we recommend using both the urine concentration of MMA and the serum vitamin B12 as prima-ry tests for diagnosis of MA caused by vitamin B12 deficiency.

Two Cases of Erythroleukemic Blast Crisis in Chronic Myelogenous Leukemia / 대한임상병리학회지

The erythroleukemic blast crisis in chronic myelogenous leukemia (CML) is rarely reported. We present two cases of erythroleukemic blast crisis of CML. In both cases, they had been treated with interferon and hydroxyurea prior to a blast crisis of CML. On blastic transformation, one patient underwent an acute clinical transformation marked with fever and hematochezia but the other showed no clinical deterioration. The blasts appeared in the peripheral blood. The bone marrow aspirates revealed megaloblastic erythroid hyperplasia (about 72%, 54% of all nucleated cells), increasing the number of myeloblasts (about 46%, 59% of all non-erythroid cells), and erythroblasts with a positive PAS stain. The cytogenetic studies revealed Philadelphia chromosomes with additional chromosomal abnormalities, t(3;21)(q26;q22) and the FISH studies revealed bcr-abl fusion signals in bone marrow cells. One case expired 8 months later despite of hydroxyuria therapy. The other case received allogeneic bone marrow transplantation (alloBMT) without complete remission but expired 34 weeks after alloBMT due to GVHD.