Human C-terminal CUBN variants associate with chronic proteinuria and normal renal function

BACKGROUNDProteinuria is considered an unfavorable clinical condition that accelerates renal and cardiovascular disease. However, it is not clear whether all forms of proteinuria are damaging. Mutations in CUBN cause Imerslund-Gräsbeck syndrome (IGS), which is characterized by intestinal malabsorption of vitamin B12 and in some cases proteinuria. CUBN encodes for cubilin, an intestinal and proximal tubular uptake receptor containing 27 CUB domains for ligand binding.METHODSWe used next-generation sequencing for renal disease genes to genotype cohorts of patients with suspected hereditary renal disease and chronic proteinuria. CUBN variants were analyzed using bioinformatics, structural modeling, and epidemiological methods.RESULTSWe identified 39 patients, in whom biallelic pathogenic variants in the CUBN gene were associated with chronic isolated proteinuria and early childhood onset. Since the proteinuria in these patients had a high proportion of albuminuria, glomerular diseases such as steroid-resistant nephrotic syndrome or Alport syndrome were often the primary clinical diagnosis, motivating renal biopsies and the use of proteinuria-lowering treatments. However, renal function was normal in all cases. By contrast, we did not found any biallelic CUBN variants in proteinuric patients with reduced renal function or focal segmental glomerulosclerosis. Unlike the more N-terminal IGS mutations, 37 of the 41 proteinuria-associated CUBN variants led to modifications or truncations after the vitamin B12-binding domain. Finally, we show that 4 C-terminal CUBN variants are associated with albuminuria and slightly increased GFR in meta-analyses of large population-based cohorts.CONCLUSIONCollectively, our data suggest an important role for the C-terminal half of cubilin in renal albumin reabsorption. Albuminuria due to reduced cubilin function could be an unexpectedly common benign condition in humans that may not require any proteinuria-lowering treatment or renal biopsy.FUNDINGATIP-Avenir program, Fondation Bettencourt-Schueller (Liliane Bettencourt Chair of Developmental Biology), Agence Nationale de la Recherche (ANR) Investissements d'avenir program (ANR-10-IAHU-01) and NEPHROFLY (ANR-14-ACHN-0013, to MS), Steno Collaborative Grant 2018 (NNF18OC0052457, to TSA and MS), Heisenberg Professorship of the German Research Foundation (KO 3598/5-1, to AK), Deutsche Forschungsgemeinschaft (DFG) Collaborative Research Centre (SFB) KIDGEM 1140 (project 246781735, to CB), and Federal Ministry of Education and Research (BMB) (01GM1515C, to CB).

Iron deficiency anemia and megaloblastic anemia in obese patients

BACKGROUND

The association between obesity and different types of anemia remained uncertain. The present study aimed to assess the relation between obesity parameters and the occurrence of iron deficiency anemia and also megaloblastic anemia among Iranian population.

METHODS AND MATERIALS

This cross-sectional study was performed on 1252 patients with morbid obesity that randomly selected from all patients referred to Clinic of obesity at Rasoul-e-Akram Hospital in 2014. The morbid obesity was defined according to the guideline as body mass index (BMI) equal to or higher than 40 kg/m2. Various laboratory parameters including serum levels of hemoglobin, iron, ferritin, folic acid, and vitamin B12 were assessed using the standard laboratory techniques.

RESULTS

BMI was adversely associated with serum vitamin B12, but not associated with other hematologic parameters. The overall prevalence of iron deficiency anemia was 9.8%. The prevalence of iron deficiency anemia was independent to patients' age and also to body mass index. The prevalence of vitamin B12 deficiency was totally 20.9%. According to the multivariable logistic regression model, no association was revealed between BMI and the occurrence of iron deficiency anemia adjusting gender and age. A similar regression model showed that higher BMI could predict occurrence of vitamin B12 deficiency in morbid obese patients.

CONCLUSION

Although iron deficiency is a common finding among obese patients, vitamin B12 deficiency is more frequent so about one-fifth of these patients suffer vitamin B12 deficiency. In fact, the exacerbation of obesity can result in exacerbation of vitamin B12 deficiency.

[Etiological profile of anemia in a department of internal medicine]

Anemia is a major public health problem worldwide despite remarkable improvement in living conditions. The World Health Organization (WHO) classifies it as one of the ten most serious problems in the world. This study aims to describe the epidemiologic and etiologic profiles of the cases of anemia treated during our training. We conducted a retrospective study involving 150 patients carried out over 5 years, from January 2011 to December 2015. The average age of our patients was 48.8 years and women were more likely to be affected than men, with a sex ratio of 1.78. The mean hemoglobin was 8 g/dl, ranging from 3.4 to 11.4 g/dl. Iron deficiency anemia was the leading etiologic diagnosis made in 60% of cases, followed by megaloblastic anemia in 21% of patients and haemolytic anemia in 7.33% of cases. The occurrence of anemia in adults may represent a real diagnostic challenge for the internist as it is sometimes associated with an emergency context. Specialized examinations may be necessary.

Bone marrow examination in pancytopenia

Pancytopenia is defined by reduction of all the three formed elements of blood below the normal reference. It may be a manifestation of a wide variety of disorders, which primarily or secondarily affect the bone marrow. Haematological investigation forms the bedrock in the management of patients with pancytopenia and therefore needs detailed study. The total number of cases studied were 100 over a period of two years in the department of pathology, JSS Hospital, Mysore. Megaloblastic anaemia (33%) was the commonest cause of pancytopenia. Other causes were nutritional anaemia (16%), aplastic anaemia (14%), hypersplenism (10%), sepsis (9%) and leukaemia (5%). Less common causes were alcoholic liver disease, haemolytic anaemia, HIV, dengue, systemic lupus erythematosus, viral hepatitis, disseminated TB and multiple myeloma. Most of the patients were in the age group of 11-30 years with a male:female ratio of 1.6:1.Generalised weakness and fatigue (88%) were the commonest presenting complaints. Haemoglobin level varied from 1-10 g/dl with majorIty (70%) of them in the range of 5.1-10 g/dI. TLC was in the range of 500-4000 cells/cmm. Most (34%) of them had 3100-4000 cells/cmm. Platelet count was in the range of 4000-1,40,000 cells/cmm. Reticulocyte count varied from 0.1%-15% with majority (82%) of them ranging from 0.1%-2%. The bone marrow cellularity was hypocellular in 14%, hypercellular in 75%, and normocellular in 11% of the patients. Pancytopenia is a relatively common entity with inadequate attention in Indian subcontinent. A comprehensive clinical and haematological study of patients with pancytopenia will usually help in the identification of the underlying cause. However in view of wide array of aetiologies, pancytopenia continues to be a diagnostic challenge for haematologists.

Frequency and characterisation of pancytopenia in megaloblastic anaemia

BACKGROUND

A wide variety of clinical conditions, that primarily or secondarily affect the bone-marrow may present with pancytopenia, one of such conditions is megaloblastic anaemia. The purpose of this study was to determine the frequency and nature of pancytopenia in megaloblastic anaemia.

METHODS

This was a prospective, cross-sectional descriptive study conducted in Medical Units, Ayub Teaching Hospital, Abbottabad, Pakistan during July 2010-January 2011. Total 90 patients were included in this study. Data were collected including history, clinical examination, haemoglobin level, mean cell volume, bone marrow examination and peripheral smear examination.

RESULTS

Of total 90 patients, 54 were male and 36 were female. Mean age was 28 +/- 15.84 years. Common presenting features were weakness, fever and bleeding manifestations. Pancytopenia was present in 63 (70%) patients. Most common presenting feature related to anaemia was weakness (80%). Bleeding manifestations, related to low platelet count were found in 35 (39%) patients. Physical Examination findings were: pallor (100%), splenomegaly (33%), bleeding manifestations (25%), hepatomegaly (17%), and hepatosplenomegaly (19%). Mean peripheral blood findings of the study population included haemoglobin level (6.25 g/dL), total leukocyte count (2818.7/microL), platelet count (44040/uL), and reticulocyte count (1.7%). Mean values for red cells indices included red blood cells count (2.6 million/uL), mean corpuscular volume (114.3 fL), mean corpuscular haemoglobin (27.3 pg) and mean corpuscular haemoglobin concentration (31.8 g/dL).

CONCLUSIONS

In megaloblastic anaemia, pancytopenia is a common and important clinical and haematological problem. Patients should be properly investigated for pancytopenia and its causes because many of them are completely curable while others are manageable. This will help to reduce patients' suffering, improve quality of life and prolong survival.

Vitamin B12 deficiency--a major cause of megaloblastic anaemia in patients attending a tertiary care hospital

BACKGROUND

Folate and vitamin B12 deficiencies have been known to cause megaloblastic anaemia. Since the deficiencies of these two vitamins are very common in Pakistani population, it would be imperative to investigate their role in causing megaloblastic anaemia. The objective of this study was to find out the contribution of folate and vitamin B12 deficiencies in causing megaloblastic anaemia in our patient population.

METHODS

In this retrospective cohort study, clinical records of 220 patients (101 females and 119 males with an age range of 1-80 years) who presented themselves with macrocytic anaemia at the Aga Khan University Hospital were collected. Data pertaining to complete blood count and serum levels of folate and vitamin B12 were analysed.

RESULTS

The mean haemoglobin (Hb) level was 6.8 +/- 0.2 gm/dl. Sixty-nine percent of the patients had severe anaemia (Hb < 8 gm/dl). Mean +/- SEM values of haemoglobin, serum folate and serum B12 were not significantly different between males and females (Hb 6.4 +/- 0.3 gm/dl vs 6.3 +/- 0.3 gm/dl; folate 6.9 +/- 0.8 etag/ml vs 7.8 +/- 1 etag/ml; B12 259 +/- 65 rhog/ml vs 225 +/- 45 rhog/ml, respectively). Linear regression analysis showed that serum folate was inversely related with the mean corpuscular volume (MCV, p = 0.04). Spearman's correlation analysis indicated an inverse mild association between MCV and serum folate (correlation coefficient = -0.18). Folate deficiency was 43.4%, while vitamin B12 deficiency was 78.5% in these patients. Seventy-one percent of folate-deficient patients had vitamin B12 deficiency as well, while 26.1% of patients with B12 deficiency had a co-occurrence of folate deficiency.

CONCLUSION

Vitamin B12 deficiency appears to be the major factor leading to megaloblastic anaemia in our study population. Inadequate dietary intake, over-cooking of our food and poor absorption might be contributing to high prevalence of vitamin B12 deficiency in this population.

Thiamine responsive megaloblastic anemia

This report describes a female child with thiamine responsive megaloblastic anemia syndrome (Rogers syndrome), presenting with anemia and diabetes mellitus responding to thiamine. She also had retinitis pigmentosa. The anemia improved and blood sugar was controlled with daily oral thiamine. Previously unreported olfactory abnormalities, as described in Wolfram syndrome, were also present in our patient.

Megaloblastic anaemia: prevalence and causative factors

BACKGROUND

Megaloblastic anaemia is not uncommon in India, but data are insufficient regarding its prevalence, and causative and precipitating factors. We did a prospective study to document such data for patients of megaloblastic anaemia.

METHODS

All patients presenting to our hospital over a period of 6 months with a haemoglobin < 10 g/dl and/or mean corpuscular volume > 95 fL and blood film findings consistent with megaloblastosis were included in the study. Demographic data, diet, drug intake, previous blood transfusion and presenting symptoms were recorded. Clinical findings were obtained from medical records of patients. Complete blood counts, blood film examination, reticulocyte count and cobalamin and folate assays were done. Results of liver function tests and bone marrow slides were available for review.

RESULTS

Megaloblastic anaemia was diagnosed in 175 patients with anaemia. Assays were done on 120 patients (55 were lost to follow up) and results showed cobalamin deficiency in 78 patients (65%), combined cobalamin and folate deficiency in 20 patients (12%) and pure folate deficiency in 8 patients (6%). Fifteen per cent of patients had normal or high values of both vitamins, having received blood or haematinics before the diagnosis was established. The peak incidence of megaloblastic anaemia was in the age group of 10-30 years (48%), with female preponderance (71%). The predominant symptoms were fatigue, anorexia and gastritis, low grade fever, shortness of breath, palpitations and mild jaundice. Twenty-five per cent of patients were on acid-suppressing medication and 15% had previous transfusion for anaemia. Eighty-seven per cent of patients with cobalamin deficiency and 75% with folate deficiency were lactovegetarians. In the combined deficiency cohort, 71% were vegetarians and 29% were occasional non-vegetarians. Physical findings were pallor (85%), glossitis (29%), mild icterus (25%) and hyperpigmentation (18%). Abnormal haematological findings were mean corpuscular volume 77-123 fL (9 patients had iron deficiency), red cell distribution width 16%-44%, pancytopenia in 62% of patients, reticulocyte count > 2% in 42% of patients and typical megaloblastic blood films in all patients. Bone marrow smears available in 22 patients showed moderate-to-severe megaloblastosis. Thirty-two per cent of patients in whom liver function tests were done showed indirect bilirubinaemia with normal enzymes.

CONCLUSION

Megaloblastic anaemia was diagnosed from complete blood counts, red cell indices, blood film examination and assays of the two vitamins. Bone marrow examination was not essential for diagnosis. Cobalamin deficiency was the major cause of megaloblastosis. Aetiological factors were a diet poor in cobalamin or folate, increased requirements during the growth period and pregnancy, and the use of acid-suppressing medication. Physicians managing these patients need to be aware of the timing of blood sampling for assays, that haematinics and transfusions provide only short term benefits, and that long term follow up and diet counselling is crucial.

Incidence of megaloblastic anaemia and its correction in leishmaniasis--a prospective study at BPKIHS hospital, Nepal

Fifty (50) cases of Leishmaniasis were included in a prospective study after making the diagnosis based on the demonstration of L D Bodies on bone marrow aspirate. Hemoglobin (Hb) and total leucocyte count (TLC) were less than 10 gm/dl and 4000 per/ml respectively in 22 out of 50 cases. Among 50 cases, 30 showed macrocytic red cell and hypersegmented neutrophils on peripheral blood smear as features of megaloblastic anemia. Out of 30 cases of leishmaniasis with megaloblastic anemia, 10 cases showed decreased reticulocyte count. Bone marrow aspiration cytology showed megaloblastic maturation in erythroid series and giant metamyelocytes in myeloid series in all 30 cases of leishmaniasis with megaloblastic changes. Bone marrow iron was also increased in these cases. However megakaryocyte was normal in all. Among 30 cases of leishmaniasis with megaloblastic changes, 15 cases were treated with sodium antimony gluconate (SAG) only and other 15 with SAG, folic acid and Vit. B12. Rest 20 cases of leishmaniasis without megaloblastic changes were also treated with SAG only. After treatment with SAG alone as well as with SAG, folic acid and vit. B12, hemoglobin and TLC improved in all 50 cases. Of 15 cases of leishmaniasis with megaloblastic changes, who were treated with SAG, folic acid and vit. B12, the reticulocyte count reached at peak on the 7th day and normalized at the end of 4th week. Red blood cells (RBC) also became normocytic normochromic and neutrophils became normal on peripheral blood smear. But no change was observed in reticulocyte count, RBC and white blood cell (WBC) morphology on peripheral blood smear in cases of leishmaniasis without megaloblastic changes and other 15 cases of leishmaniasis with megaloblastic changes, who received SAG only.

Megaloblastic anemia in North Africa

We prospectively studied 478 patients with megaloblastic anemia living in Tunisia. Overall, 98% of patients had vitamin B12 deficiency. Pernicious anemia accounted for most of these cases, and median age at presentation was 45 years. Megaloblastic anemia occurred in 19 subjects under 15 years of age, and of these, nine had the Immerslund-Graesbeck syndrome.

Spectrum of anemia in pregnant Indian women and importance of antenatal screening

Anemia is a common health problem but control of anemia in pregnant women is less well studied. The purpose was to study prevalence of anemia in young pregnant women, correlate with indices and study significance of identification of hemoglobinopathies. Of the 120 pregnant women, Hb was less than 8 g% in 58 (44.2%). Seventy-eight (65%) had iron deficiency, 22 (18.3%) had dimorphic anemia, and 14 (11.6%) had hemolytic anemia. Megaloblastic anemia was present in 6 (5%). Of hemolytic anemia, 50% were thalassemia trait. MCV< 76 fl was observed in 88 (73.3 %) cases. MCV<76 fl and MCH < 27 pg had 100 % sensitivity and 28.7 % specificity for screening of beta-thalassemia trait. NESTROFT had comparable sensitivity but lower specificity (14.9%). Sixty-three percent (60/78) of IDA had increased RDW whereas 78 % (11/14) of hemolytic anemia had RDW value in normal range (p value< 0.05). MCV/RBC of <14 was more specific parameter (96.8%) for beta-thalassemia trait. Four high-risk couples were identified. Thus, moderate to severe anemia was observed in most pregnant women. Hemoglobinopathies should be screened in antenatal clinics to identify the couples that would need a prenatal test. A lower MCV/RBC with RDWin the normal range may be useful in screening for thalassemia trait in pregnant women.

Imerslund-Gräsbeck syndrome (selective vitamin B(12) malabsorption with proteinuria)

Imerslund-Gräsbeck syndrome (IGS) or selective vitamin B(12) (cobalamin) malabsorption with proteinuria is a rare autosomal recessive disorder characterized by vitamin B(12) deficiency commonly resulting in megaloblastic anemia, which is responsive to parenteral vitamin B(12) therapy and appears in childhood. Other manifestations include failure to thrive and grow, infections and neurological damage. Mild proteinuria (with no signs of kidney disease) is present in about half of the patients. Anatomical anomalies in the urinary tract were observed in some Norwegian patients. Vitamin B(12) absorption tests show low absorption, not corrected by administration of intrinsic factor. The symptoms appear from 4 months (not immediately after birth as in transcobalamin deficiency) up to several years after birth. The syndrome was first described in Finland and Norway where the prevalence is about 1:200,000. The cause is a defect in the receptor of the vitamin B(12)-intrinsic factor complex of the ileal enterocyte. In most cases, the molecular basis of the selective malabsorption and proteinuria involves a mutation in one of two genes, cubilin (CUBN) on chromosome 10 or amnionless (AMN) on chromosome 14. Both proteins are components of the intestinal receptor for the vitamin B(12)-intrinsic factor complex and the receptor mediating the tubular reabsorption of protein from the primary urine. Management includes life-long vitamin B(12) injections, and with this regimen, the patients stay healthy for decades. However, the proteinuria persists. In diagnosing this disease, it is important to be aware that cobalamin deficiency affects enterocyte function; therefore, all tests suggesting general and cobalamin malabsorption should be repeated after abolishment of the deficiency.

Prevalence and etiology of acquired anemia in Medieval York, England

This paper presents three distinct models for the development of acquired anemia: iron-deficiency anemia produced by the inadequate intake and/or absorption of iron, the anemia of chronic disease (ACD) caused by the body's natural iron-withholding defense against microbial invaders, and megaloblastic anemia caused by insufficient intake and/or absorption of vitamin B(12) or folic acid. These etiological models are used to interpret the distribution and etiology of anemia among adult individuals interred at the Medieval Gilbertine Priory of St. Andrew, Fishergate, York (n = 147). This bioarchaeological analysis uncovered not only a strong relationship between decreasing status and increasing prevalence of anemia for both men and women, but also identified clear sex-based differences at this site. Within the high-status group, blood and iron loss as a result of rampant parasitism likely produced an environment ripe for the development of iron-deficiency anemia, while the parasitic consumption of vitamin B(12) may have caused occasional cases of megaloblastic anemia. As status decreases, the interpretation of anemia becomes more complex, with megaloblastic anemia and ACD emerging as viable, potentially heavy contributors to the anemia experiences of low-status people at St. Andrew's. Apart from status effects, women (especially young women) are disproportionately affected by anemia when compared to men within their own status group and, on average, are also more likely to have experienced anemia than their male peers from other status groups. This suggests that high iron-demand reproductive functions helped to make iron-deficiency anemia a chronic condition in many women's lives irrespective of their status affiliation.

High prevalence of folic acid and vitamin B12 deficiencies in infants, children, adolescents and pregnant women in Venezuela

BACKGROUND

There is increased worldwide concern about the consequences of folic acid and vitamin B12 deficiencies on health, which include megaloblastic anemia, neural tube defects and cardiovascular disease.

OBJECTIVE

This study intended to determine the prevalence of folic acid and vitamin B12 deficiencies in vulnerable groups in labor and poor socioeconomic strata of the Venezuelan population.

METHODS

A total of 5658 serum samples were processed to determine folic acid and vitamin B12 concentrations. The study involved three surveys performed during 2001-2002 and included infants, children, adolescents and pregnant women from labor and poor socioeconomic strata of the population. The method used was a radio immunoassay designed for the simultaneous measurement of serum folic acid and vitamin B12.

RESULTS

The prevalence of folic acid deficiency was higher than 30% for all groups studied, reaching 81.79% in adolescents. Vitamin B12 deficiency was 11.4% in samples collected nationwide, but there was also a similar prevalence of high serum levels. The prevalence of folic acid and vitamin B12 deficiencies in pregnant women reached 36.32 and 61.34%, respectively.

CONCLUSION

This work shows that there is a high prevalence of folic acid deficiency, especially in women of reproductive age, pregnant adolescents and in the whole population studied in Vargas state. This situation requires immediate intervention as supplementation or food fortification programs.

Vitamin B12 deficiency as a worldwide problem

Pernicious anemia is a common cause of megaloblastic anemia throughout the world and especially in persons of European or African descent. Dietary deficiency of vitamin B12 due to vegetarianism is increasing and causes hyperhomocysteinemia. The breast-fed infant of a vitamin B12-deficient mother is at risk for severe developmental abnormalities, growth failure, and anemia. Elevated methylmalonic acid and/or total homocysteine are sensitive indicators of vitamin B12-deficient diets and correlate with clinical abnormalities. Dietary vitamin B12 deficiency is a severe problem in the Indian subcontinent, Mexico, Central and South America, and selected areas in Africa. Dietary vitamin B12 deficiency is not prevalent in Asia, except in vegetarians. Areas for research include intermittent vitamin B12 supplement dosing and better measurements of the bioavailability of B12 in fermented vegetarian foods and algae.

Thiamine-responsive megaloblastic anemia syndrome: a disorder of high-affinity thiamine transport

Thiamine-responsive megaloblastic anemia (TRMA) syndrome (OMIM No. 249270) comprises a distinctive triad of clinical features: megaloblastic anemia with ringed sideroblasts, diabetes mellitus, and progressive sensorineural deafness. The TRMA gene has been mapped and cloned. Designated "SLC19A2" as a member of the solute carrier gene superfamily, this gene is mutated in all TRMA kindreds studied to date. The product of the SLC19A2 gene is a membrane protein which transports thiamine (vitamin B1) with sub-micromolar affinity. Cells from TRMA patients are uniquely sensitive to thiamine depletion to the nanomolar range, while pharmacologic doses of vitamin B1 ameliorate the anemia and diabetes. Here we review the current status of studies aimed at understanding the pathophysiology of this unique transport defect.

Heterozygous beta-thalassemia: not infrequent in Mexico

BACKGROUND

The prevalence of beta-thalassemia in Mexico is not known in detail.

METHODS

Data of studies investigating abnormal hemoglobins between September 1987 and November 2000 were analyzed; in addition, data of red-blood-cell indices and clinical features were analyzed in patients identified as carriers of beta-thalassemia.

RESULTS

In 1,639 prospective studies looking for abnormal hemoglobins, 429 disclosed some abnormality; of these, 319 cases displayed abnormally high levels of hemoglobin A2, thus consistent with the diagnosis of beta-thalassemia. This hemoglobin abnormality represented 74.2% of all abnormalities, both quantitative and qualitative, of the molecule of hemoglobin. There were 317 heterozygotes and only two homozygotes. We have previously shown that the most frequent cause of anemia as the iatrotropic condition in Mexican mestizos is iron deficiency. We found that iron deficiency is 11.5 times more frequent than beta-thalassemia and that the latter is 1.3 times more frequent than macrocytic/megaloblastic anemia.

CONCLUSIONS

beta-thalassemia should not be considered as infrequent in Mexico, and individuals with red blood cell microcytosis and/or hypochromia with or without anemia should be screened for thalassemia.

Clinicopathological features of megaloblastic anaemia in Hong Kong: a study of 84 Chinese patients

Megaloblastic anaemia is uncommon in Hong Kong. Eighty-four consecutive Chinese patients with megaloblastic anaemia were studied. There were 48 males and 36 females, with a median age at presentation of 67 years. Vitamin B12 deficiency was found in all cases, with none of the patients showing folate deficiency. The frequency of pernicious anaemia in our patients was higher than in other south-east Asian series but comparable with western ones. When compared with patients in the West, our cases showed the following main differences: virtual absence of folate deficiency, even in alcoholics; absence of associated gastric malignancies; and a high frequency of tuberculosis.

Megaloblastic anaemia in Zimbabwe: spectrum of clinical and haematological manifestations

An analysis of 100 cases (43 males and 57 females) with confirmed megaloblastic anaemia is presented. The age distribution showed two peaks with 18% in the third and fourth decades and 25% in the seventh decade. Anaemia of moderate to severe degree occurred in all patients and accounted for the commonest triad of symptoms at presentation viz: weakness (73%); breathlessness (40%) and headaches (33%). Macrocytosis or macroovalocytosis and neutrophil hyper-lobulation were found in all cases; MCV greater than 100fl in 84%; pancytopenia in 47%; and megaloblastic haematopoiesis found in all patients varied from moderate to gross in severity. Thus, the finding of macrocytic anaemia with a high MCV particularly in excess of 100fl, neutrophil hypersegmentation, and characteristic megaloblastic changes in the bone marrow should dictate further appropriate investigations to help in establishing the specific diagnosis if appropriate therapeutic intervention is to be ultimately instituted.

Nutritional anaemias

Nutritional anaemia is recognized as a major public health problem throughout the world, especially in developing countries. Infants, young children, menstruating women and, in particular, pregnant women are most frequently affected. Sufficient evidence suggests that iron deficiency is the most common cause of nutritional anaemia in the world. Folate deficiency is considered as the second most common cause. In this chapter we discuss the factors determining nutritional inadequacy in iron and folate requirements versus iron and folate intake, particularly in different age/sex categories; the amounts of iron and folate involved in daily exchange and the role of the diet and physiological and pathological variations in losses and requirements are reviewed. The consequences in terms of health of iron and folate deficiencies and methods for assessing iron and folate status of populations are also presented.

Imerslund-Gräsbeck syndrome in a Saudi family

Imerslund-Gräsbeck syndrome, an autosomal recessive trait of defective uptake of intrinsic factor-vitamin B12 complex by terminal ileum, is described in a Saudi family (two siblings and their first cousin). This rare disease has previously been reported only in Northern Europe and North African Jewish ethnic groups.

Patterns of erythropoiesis and anaemia in malaria

Of 138 patients with malaria, 90 were found to be having Plasmodium falciparum in their peripheral blood smears. Megaloblastosis alone or in combination with the other patterns of erythropoiesis was observed in 82.1 percent cases of chronic P. falciparum malaria as compared to 36.3 and 26.5 per cent cases of acute P. falciparum and P. vivax malaria respectively. Iron deficiency was observed in 15.5 percent cases of chronic P. falciparum, 18.2 per cent cases of acute P. falciparum and 13.3 per cent patients of P. vivax infection. Of patients with chronic falciparum malaria, 33.3 percent revealed features of both megaloblastosis and defective iron utilization and transient hypoplasia of marrow was observed in 8.9 per cent of these cases.

Megaloblastic anaemia in Zimbabwe. II: Diagnostic significance of red cell indices in

Studies of red cell indices viz: Rbc count, Hb, Hct ratio, MCV, MCH and MCHC were carried out in normal subjects (n = 62) and in patients with: B12 deficiency (n = 34); folate deficiency (n = 17); and B12 and folate deficiency (n = 18). Although these red cell parameters were diagnostically useful (2P less than 5 x 10(-3)) in distinguishing the patients' groups from the control group; they showed no ability to distinguish the deficient groups from each other. However, their practical and diagnostic significance as screening tests in the local environs is briefly highlighted.

Megaloblastic anaemia in Zimbabwe. 1: Seasonal variation

Two hundred and ten patients who were confirmed to have megaloblastic anemia over a 2-year period were grouped according to the month of diagnosis. A distinct seasonal variation was detectable in the occurrence of megaloblastic anemia with a high prevalence in the wet season and a low prevalence in the dry season. The major factor postulated to be responsible for the seasonal fluctuations of the disorder is the concomitant diminution in the availability of folate-rich green vegetables; and not malaria transmission. As the dry season sets in and progresses, the frequency of megaloblastic anaemia cases increases reaching a peak during the wet season. It is suggested that an adequate supply of green vegetables like lettuce, spinach and cabbage throughout the year might lessen or even eliminate the seasonal variation of megaloblastic anaemia presently observed in this community.

Anaemia in Asians in London

Many Asian subjects were seen in London in the early 1970s with megaloblastic anaemia; in a majority of cases, this was dietary in origin. Pernicious anaemia occurs in Asians, but the incidence is probably lower than in Caucasians. Megaloblastic anaemia is now less common in this group, but a population survey in Punjabi females in the late 1970's showed anaemia in 32%, and one or more features of iron deficiency in 76%.

The changing pattern of megaloblastic anemia: megaloblastic anemia in Israel

The causes of megaloblastic anemia were studied in a survey of patients admitted to six Israeli hospitals over a period of 15 yr. Among the 203 patients identified, 69% had pernicious anemia, 12% had gastrointestinal disease, 9% had primary nutritional deficiency of whom only 1% were associated with pregnancy, and 7% had selective vitamin B12 malabsorption with albuminuria. Comparison with previously published surveys showed, that in contrast with earlier studies where primary nutritional deficiency was the cause of megaloblastic anemia in about 70% of cases and pernicious anemia in only 20%, in more recent studies the proportion of cases with primary nutritional anemia in general and those associated with pregnancy in particular was much lower. This is most probably the result of improved standards of living and a national program of preventive folate supplementation at maternity clinics. A potential hazard of such preventive programs is the aggravation of neurological complications in patients with undiagnosed vitamin B12 deficiency. Early recognition of pernicious anemia and other forms of selective B12 malabsorption is a new challenge created by the changing pattern of megaloblastic anemias.

Nutritional anaemias. Part 1: Tropical Africa

A review of nutritional anaemia in Africa is presented above. It has been noted that nutritional anaemia, including iron-deficiency anaemia, megaloblastic anaemia due to folate deficiency or vitamin B12 deficiency, or both, and protein deficiency-anaemia, is widespread throughout Africa. It is particularly common in growing children, women of child-bearing age, pregnant women and lactating mothers. The anaemia is also especially common during the second half of the dry season and the first half of the wet season, when food supplies are limited. In all cases the anaemia is caused either by limited dietary intake, excessive loss of nutrients or excessive utilization. The anaemia is associated with a number of sequelae including both structural changes, like mitochondrial swelling and mucosal atrophy, and functional abnormalities, such as cardiac failure, decreased work output, increased pregnancy risks and increased susceptibility to infections. The evidence in favour of increased susceptibility to infections in megaloblastic anaemia and protein-deficiency anaemia is overwhelming, but in iron-deficiency anaemia the available information argues in favour of reduced susceptibility to infections, except after initiation of iron therapy. The treatment of nutritional anaemia includes replacement of the deficient nutrients (and blood transfusion in severe cases), prevention of further nutrient losses and treatment of associated complications.

Anaemia of pregnancy in northern India. Nature and therapeutic follow-up

Investigations on 114 anaemic pregnant women revealed that megaloblastosis occurred in more than half. A therapeutic follow-up approach clearly indicated that vitamin B12-deficiency was fairly common in such patients; the need of iron supplementation in many of them for achieving complete remission emphasized the poor status of iron stores. All patients with normoblastic marrow achieved full remission with iron therapy alone. The deficiency of haematinic factors appears to be largely due to poor nutrition.

Significance of subnormal red-cell folate in thalassaemia

Subnormal red-cell folate values were encountered in 20 of 63 thalassaemic subjects in a population with a low incidence of megaloblastosis. The abnormality was not associated with haematological changes of megaloblastosis and could not be explained on the basis of incomplete liberation of intra-erythrocytic folates, serum conjugase deficiency of vitamin B12 deficiency. Evidence is presented to indicate that it is unlikely to represent a state of subclinical folate deficiency. The exact cause of the abnormality is unknown.

Anaemia of pregnancy: the changing postwar pattern

A popluation survey covering over a quarter of a century has shown clearly the improvement in haemoglobin levels in women attending antenatal clinics at the Glasgow Royal Maternity Hospital. Various influences have helped to bring this about, foremost among these being routine early prophylaxis with combined iron and folate supplements. Indeed, a time-space relationship between changes in prophylactic therapy, rates of improvement, and the incidence of megaloblastic anaemia can be shown. The women at risk are still essentially the same except for a new group of young, unmarried girls, who must be watched. In our view the withdrawal of routine prophylactic therapy in pregnancy would be retrograde step.