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Serum ferritin in haemoglobin H

George E, Faridah K

Family Practitioner, 1986;9:38-40.

Matched MeSH terms: Ferritins
Fulltext Ferritin level: A predictor of severity and mortality in hospitalized COVID-19 patients

Alroomi M, Rajan R, Omar AA, Alsaber A, Pan J, Fatemi M, et al.

Immun Inflamm Dis, 2021 Dec;9(4):1648-1655.
PMID: 34438471 DOI: 10.1002/iid3.517

INTRODUCTION: This study aims to investigate in-hоsрitаl mоrtаlity in severe асute resрirаtоry syndrоme соrоnаvirus 2 раtients strаtified by serum ferritin levels.
METHODS: Patients were stratified based on ferritin levels (ferritin levels ≤ 1000 or >1000).
RESULTS: Approximately 89% (118) of the patients with ferritin levels > 1000 had pneumonia, and 51% (67) had hypertension. Fever (97, 73.5%) and shortness of breath (80, 61%) were two major symptoms among the patients in this group. Logistic regression analysis indicated that ferritin level (odds ratio [OR] = 0.36, 95% confidence interval [CI] = 0.21-0.62; p 1000.
CONCLUSION: In this study, higher levels of serum ferritin were found to be an independent predictor of in-hоsрitаl mоrtаlity.

Matched MeSH terms: Ferritins
Fulltext Iron stores in pregnancy

George E, Adeeb N, Ahmad J

Med J Malaysia, 1980 Dec;35(2):129-30.
PMID: 7266404

Serum ferritin concentration has been measured in pregnant women at their first antenatal visit. Results were analysed according to trimesters. With progression of the pregnancy there is a fall in serum ferritin concentrations. Haemoglobin and red cell indices cannot be used to predict iron status supplemental iron therapy raised the serum ferritin levels.

Matched MeSH terms: Ferritins/blood
Fulltext Suggestion of an active transport of iron to the fetus in human pregnancy and its dependence on maternal serum iron levels

Ali J, Hassan K, Arshat H

Med J Malaysia, 1981 Dec;36(4):215-9.
PMID: 7334956

The present findings suggest the possible involvement of an active mechanism for transport of iron to the fetus. In all the 19 subjects studied, the cord serum iron levels tended to be higher (129.2 ± 56.8 ug/100ml) than the maternal serum iron levels (74.0 ± 35.9 ug/100ml) at parturition even in maternal iron deficiency. The significant difference (P< 0.001) between cord serum iron levels and the maternal iron levels shows that an active transport mechanism working against a gradient in favour of the fetus exists. The availability of iron to the fetus appears to be dependent on maternal serum iron levels but not on maternal iron stores. This finding serves to stress the importance of iron supplements in pregnancy. A hypothetical model for iron transfer from maternal circulation to fetal circulation is described.

Matched MeSH terms: Ferritins/blood
Serum ferritin concentrations in male Malaysian blood donors

Ton SH, Lopez CG

Southeast Asian J. Trop. Med. Public Health, 1980 Mar;11(1):87-90.
PMID: 7403958

Serum ferritin and haemoglobin estimates were carried out on 78 first time blood donors with a view to determining iron store status. Of these 30 were Malays, 20 were Chinese and 28 were Indians. The ferritin level in Malay donors ranged from 16-160 mg/ml (mean 83 +/- 49.4 mg/ml in chinese donors is ranged from 36-500 mg/ml (mean 242.8 +/- 132 mg/ml), and in the Indian donors it ranged from 5 - 270 mg/ml (mean 94.6 +/- 67.9 mg/ml). The haemoglobin concentration for the whole group was 14.9 +/- 1.49 g/dl. There was no correlation of haemoglobin concentration with serum ferritin levels.

Matched MeSH terms: Ferritins/blood*
Fulltext Iron-deficiency anaemia and serum ferritin levels in Malaysian women

Goh TH, Hariharan M

Med J Malaysia, 1986 Dec;41(4):300-4.
PMID: 3670151

Serum ferritin and blood haemoglobin levels were studied in 229 women attending a family planning clinic. Ferritin values ranged from 2 to 438 Jlg/l and was skewed with an arithmetic mean of 41.8 and geometric mean of 23.4 flg/l; 26.6% were iron-deficient (ferritin < 12 Jlg/l). Haemoglobin values were normally distributed with a mean of 11. 7 g/dl but 59% were anaemic (Hb < 12 gjdl]. The correlation between ferritin and haemoglobin values was poor (r = 0.147) but almost all women with a haemoglobin below 10 g/dl were iron-deficient. This study reaffirms the need for monitoring iron-deficiency anaemia in apparently healthy women seeking contraception.

Matched MeSH terms: Ferritins/blood*
The predictive role of biomarkers for mortality in COVID-19 patients

Savrun A, Aydin IE, Savrun ST, Karaman U

Trop Biomed, 2021 Sep 01;38(3):366-370.
PMID: 34508345 DOI: 10.47665/tb.38.3.080

Many biomarkers are used in addition to radiologic examinations to determine the severity of COVID-19. This study aims to determine WBC, neutrophil, lymphocyte, platelet, D-dimer, CRP, AST, ALT, LDH, PT, APTT, INR, urea, creatinine, lactate, and ferritin levels in COVID-19 patients and the effect of their changes on mortality rate. The study was conducted between 11 March 2020 and 31 August 2020 (during the COVID-19 pandemic). A total of 502 patients older than 18 years who presented with suspected COVID-19 were included in the study. Of these 502 patients who applied to the hospital, 229(45.6%) were male and 273(54%) were female. 301(60%) patients were diagnosed with COVID-19 through computed tomography and PCR tests. 201(40%) patients with negative test results constituted the control group. Patients with positive test results 48.2% (n=145) were men, and 51.8% (n=156) were women. The median age of the patients was 51±25 years. The patients tested positive for COVID-19 were divided into three groups as outpatients (26.9%), inpatients (68.8%), and intensive care unit patients (4.3%). The mortality rate of the patients followed via the patient follow-up system after 30 days was determined as 2.7%. The biomarker values of patients examined in this study tested negative and positive for COVID-19 were compared. In the study, D-dimer, ferritin, Lactate, AST, ALT, LDH, Urea, Creatinine, APTT, and INR levels were found to be higher in the positive tested patients than the negative ones. In the study, it was concluded that neutrophil, lymphocyte, CRP, and ferritin ratios should also be followed in the follow-up phase of the disease. It is important that additional measures should be taken in cases when these biomarkers increase by following the values of the patients who started taking treatment. Also, the ratio of biomarkers is crucial in determining whether the treatment has been effective or not.

Matched MeSH terms: Ferritins/blood
Fulltext Body iron status and gastric cancer risk in the EURGAST study

Fonseca-Nunes A, Agudo A, Aranda N, Arija V, Cross AJ, Molina E, et al.

Int J Cancer, 2015 Dec 15;137(12):2904-14.
PMID: 26135329 DOI: 10.1002/ijc.29669

Although it appears biologically plausible for iron to be associated with gastric carcinogenesis, the evidence is insufficient to lead to any conclusions. To further investigate the relationship between body iron status and gastric cancer risk, we conducted a nested case-control study in the multicentric European Prospective Investigation into Cancer and Nutrition (EPIC) study. The study included 456 primary incident gastric adenocarcinoma cases and 900 matched controls that occurred during an average of 11 years of follow-up. We measured prediagnostic serum iron, ferritin, transferrin and C-reactive protein, and further estimated total iron-binding capacity (TIBC) and transferrin saturation (TS). Odds ratios (ORs) and 95% confidence intervals (CIs) for the risk of gastric cancer by iron metrics were estimated from multivariable conditional logistic regression models. After adjusting for relevant confounders, we observed a statistically significant inverse association between gastric cancer and ferritin and TS indices (ORlog2 = 0.80, 95% CI = 0.72-0.88; OR10%increment = 0.87, 95% CI = 0.78-0.97, respectively). These associations appear to be restricted to noncardia gastric cancer (ferritin showed a p for heterogeneity = 0.04 and TS had a p for heterogeneity = 0.02), and no differences were found by histological type. TIBC increased risk of overall gastric cancer (OR50 µg/dl = 1.13, 95% CI = 1.02-1.2) and also with noncardia gastric cancer (p for heterogeneity = 0.04). Additional analysis suggests that time between blood draw and gastric cancer diagnosis could modify these findings. In conclusion, our results showed a decreased risk of gastric cancer related to higher body iron stores as measured by serum iron and ferritin. Further investigation is needed to clarify the role of iron in gastric carcinogenesis.

Matched MeSH terms: Ferritins/blood*
Hyperferritinemia in Severe Dengue Infection: Single-Center Retrospective Cohort Study

Lakshmanan C, Ranjit S, Natraj R, Venkatachalapathy P, Kumar VS, Lum LCS

Pediatr Crit Care Med, 2023 Sep 01;24(9):e409-e416.
PMID: 37125796 DOI: 10.1097/PCC.0000000000003250

OBJECTIVES: Hyperferritinemia in the critical phase of dengue infections may correlate with severe dengue ( sd ) disease, and our primary objective was to examine the association between ferritin level on day 1 of PICU admission and 2009 World Health Organization (WHO) criteria for sd . Our secondary objective was outcome in relation to care. It is unclear whether immunomodulatory therapy during the critical phase may restore immune homeostasis and mitigate disease severity.
DESIGN, SETTING, AND PATIENTS: Retrospective cohort study of children with dengue 1 month to 16 years old with admission ferritin greater than or equal to 500 ng/mL requiring PICU admission. Demographics, clinical, and laboratory parameters, presence of the 2009 WHO sd criteria and outcomes were analyzed. Immunomodulatory therapy was used when there was persistent hyperinflammation beyond the critical phase of plasma leakage.
INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: Fifty-five patients were admitted in the critical phase of dengue with median (interquartile range) ferritin levels of 8,105 ng/mL (2,350-15,765 ng/mL). Patients with at least one WHO sd category had higher ferritin levels compared to those without any sd criteria, with the highest levels in eight patients with all three sd categories. In our cohort of 55, 52 patients (94%) recovered with standard supportive therapy. Recovery was associated with decreased ferritin levels that occurred in parallel with improved circulation and platelet counts; this included 22 of 24 patients with admission ferritin levels greater than or equal to 10,000 ng/mL and two with ferritin greater than 1,00,000 ng/mL. Immunomodulation was used in three patients with unremitting fever, persistent hyperferritinemia, and progressive multiple organ dysfunction beyond the critical phase, of whom two died.
CONCLUSIONS: Hyperferritinemia in the critical phase of sd is associated with the number of 2009 WHO sd criteria present. Our data also indicate that many patients with sd recover well with supportive care.

Matched MeSH terms: Ferritins
Fulltext Cloning and characterisation of multiple ferritin isoforms in the Atlantic salmon (Salmo salar)

Lee JH, Pooley NJ, Mohd-Adnan A, Martin SA

PLoS One, 2014;9(7):e103729.
PMID: 25078784 DOI: 10.1371/journal.pone.0103729

Ferritin is a highly-conserved iron-storage protein that has also been identified as an acute phase protein within the innate immune system. The iron-storage function is mediated through complementary roles played by heavy (H)-chain subunit as well as the light (L) in mammals or middle (M)-chain in teleosts, respectively. In this study, we report the identification of five ferritin subunits (H1, H2, M1, M2, M3) in the Atlantic salmon that were supported by the presence of iron-regulatory regions, gene structure, conserved domains and phylogenetic analysis. Tissue distribution analysis across eight different tissues showed that each of these isoforms is differentially expressed. We also examined the expression of the ferritin isoforms in the liver and kidney of juvenile Atlantic salmon that was challenged with Aeromonas salmonicida as well as in muscle cell culture stimulated with interleukin-1β. We found that each isoform displayed unique expression profiles, and in certain conditions the expressions between the isoforms were completely diametrical to each other. Our study is the first report of multiple ferritin isoforms from both the H- and M-chains in a vertebrate species, as well as ferritin isoforms that showed decreased expression in response to infection. Taken together, the results of our study suggest the possibility of functional differences between the H- and M-chain isoforms in terms of tissue localisation, transcriptional response to bacterial exposure and stimulation by specific immune factors.

Matched MeSH terms: Ferritins/genetics*; Ferritins/metabolism
Fulltext Iron deficiency in heart failure patients with reduced ejection fraction and the correlation with left ventricular ejection fraction

Kok Leng Tan, Seng Loong Ng, Soon Eu Chong1, W Yus Haniff W Isa, Hady, Jun Jie Tan, et al.

Malaysian Journal of Medicine and Health Sciences, 2020;16(1):131-136.
MyJurnal

Introduction: Iron deficiency (ID) has recently been identified as a threat to patients with heart failure with reduced ejection fraction (HFrEF). This study was conducted to determine the occurrence of ID among HFrEF patients in a Malaysian tertiary hospital and its correlation between left ventricular ejection fraction (LVEF). Methods: Stable patients with LVEF less than 45% were included. Demographic data, LVEF (Simpsons) and cardiac functional status were studied, along with full blood count and iron profile. Results: 81 patients with a mean LVEF of 33.6% were recruited. 43.2% of them were NYHA class II patients, followed by 38.3% class III, 13.6% class I and 4.9% class IV patients. About 2/5 of the study population were anaemic, and of those, 48.5% were iron deficient. Majority of these anaemic patients (87.5%) had an absolute iron deficiency. Pearson’s statistical analysis showed positive correlation between ejection fraction and serum ferritin (r=0.624, p< 0.001), serum iron (r= 0.302, p

Matched MeSH terms: Ferritins
Heterogenous beta-thalassaemia: Evaluation of the iron status

George-Kodiseri E, Faridah K, Mariam S

Family Physician, 1989;1:31-33.

Anaemia is present in 31.3% of male and 73.6% of female subjects heterogenous for beta thalassaemia. In males, none had serum ferritin (SF) levels less than 10 ng/ml. In contrast, female subjects with haemoglobins less than 12 gm/dl, had SF levels less than 20 ng/ml. Statistical differences in the Hb, RBC, MCV, MCH, MCHC abd HBA were found with the normal groups (p<0.001). Comparison of the SF levels in both the males and females show no difference from those in the normal groups (p<0.10). Iron loading was not a significant feature in both the males and females. Correlation of the SF with age shows a weak negative correlation. Married females with children showed that the SF levels fell significantly with increasing age, suggesting the possibility that repeated pregnancies may deplete iron stores as reflected by the SF levels. In countries where iron deficiency and thalassaemia are highly prevalent, assays of serum ferittin will indicate if there is a need for supplemental iron in subjects hetergenous for beta thalassaemia.

Matched MeSH terms: Ferritins
The effectiveness of supervised weekly versus unsupervised daily oral iron supplementation regimes in improving the status of iron deficiency in preschool Orang Asli children

Aisyah, H.M.R., Syed Zulkifli, S.Z., Noor Khatijah, N.

Malaysian Journal of Paediatrics and Child Health, 2005;14(1):14-20.
MyJurnal

OBJECTIVE: To assess a better strategy to implement oral iron supplementation in preschool Orang Asli children with high prevalence of iron deficiency, as opposed to the current practice, yet inefficient, of daily oral iron supplementation regime.
METHODS: A randomized controlled trial was conducted in preschool children presenting to a remote health center (Klinik Desa Kenang, Sungai Siput, Perak) with iron deficiency state. Oral iron prescribed as a daily unsupervised dose (group A) was compared to a weekly supervised administration (group B) over eight weeks.
RESULTS: Before intervention, iron deficiency was prevalent in these children (91.2%). The mean baseline haemoglobin and ferritin levels of group A were 9.9 (+/- 1.1) g/dL and 8.9 (+/- 1.3) mg/L respectively, and that of group B were 9.9 (+/-1.2) g/dL and 9.7 (+/- 1.9) mg/L respectively. After eight weeks of treatment, the mean rise in haemoglobin and ferritin levels of group A were 1.2 (+/- 0.6) g/dL and 18.1 (+/- 15.1) mg/ L respectively, as compared to group B, where the mean rise in haemoglobin and ferritin levels were 1.8 (+/- 0.7) g/dL and 35.2 (+/- 21.8) mg/ L respectively. The differences in the rise of haemoglobin and ferritin levels of the two groups were statistically significant (p<0.025). Both regimes were however effective in improving the iron status in a short term (88% in group A and 100% in group B), but group B had a better iron improvement (35.2 +/- 21.8 versus 18.1 +/-15.1 mg/L).
CONCLUSION: It was concluded that the supervised weekly oral iron supplementation regime was more effective than the unsupervised daily supplementation for treating iron deficiency in preschool Orang Asli children. Since iron deficiency is so common in these children and in view of the possibility of poor compliance with the unsupervised regime, an intermittent supervised treatment is proposed as the most effective strategy to address this nutritional problem.

Matched MeSH terms: Ferritins
Fulltext Antenatal iron deficiency in an urban Malaysian population

Mahdy, Z.A., Rahana, A.R., Zaleha, M.I., Muhammad Za’im, S.H., Mukudan, K., Jumaida, A.B.

Medicine & Health, 2017;12(1):27-33.
MyJurnal

Iron deficiency anemia is the most common form of anemia in pregnancy. The present study was carried out to determine the prevalence of antenatal anemia and iron deficiency in the Malaysian population and its correlation with sociodemographic and obstetric profile. It was a cross-sectional study conducted at an urban health clinic over a period of six months. A single blood sample was drawn from apparently healthy pregnant mothers at antenatal booking and sent for laboratory assessment of full blood count and serum ferritin as screening tools for anemia and iron status. SPSS version 19.0 was used for statistical analyses. The results showed that out of 250 subjects, 43.6% had anemia and 31.6% had iron deficiency. Whilst 47.7% of subjects with anemia were iron deficient, 19.1% of subjects without anemia were also iron deficient. Serum ferritin correlated negatively with period of gestation at booking (p<0.001), with 77.6% of these women not having prior iron supplements. Serum ferritin was also significantly lower among grandmultiparae (p=0.01). Iron deficiency was significantly (p=0.024) more common among Indians (42.5%) compared to Malays (33.5%) and Chinese (13.0%). In conclusion, continuation of the current practice of routine antenatal iron supplementation is still warranted and justifiable in Malaysia as there is high prevalence of iron deficiency in pregnancy not only in the presence of anemia but also in the presence of normal hemoglobin values. Keywords: anaemia, ferritn, pregnancy

Matched MeSH terms: Ferritins
Fulltext Role of Intracellular Iron in Switching Apoptosis to Ferroptosis to Target Therapy-Resistant Cancer Stem Cells

Pandrangi SL, Chittineedi P, Chalumuri SS, Meena AS, Neira Mosquera JA, Sánchez Llaguno SN, et al.

Molecules, 2022 May 07;27(9).
PMID: 35566360 DOI: 10.3390/molecules27093011

Iron is a crucial element required for the proper functioning of the body. For instance, hemoglobin is the vital component in the blood that delivers oxygen to various parts of the body. The heme protein present in hemoglobin comprises iron in the form of a ferrous state which regulates oxygen delivery. Excess iron in the body is stored as ferritin and would be utilized under iron-deficient conditions. Surprisingly, cancer cells as well as cancer stem cells have elevated ferritin levels suggesting that iron plays a vital role in protecting these cells. However, apart from the cytoprotective role iron also has the potential to induce cell death via ferroptosis which is a non-apoptotic cell death dependent on iron reserves. Apoptosis a caspase-dependent cell death mechanism is effective on cancer cells however little is known about its impact on cancer stem cell death. This paper focuses on the molecular characteristics of apoptosis and ferroptosis and the importance of switching to ferroptosis to target cancer stem cells death thereby preventing cancer relapse. To the best of our knowledge, this is the first review to demonstrate the importance of intracellular iron in regulating the switching of tumor cells and therapy resistant CSCs from apoptosis to ferroptosis.

Matched MeSH terms: Ferritins
Utility of labile plasma iron and transferrin saturation in addition to serum ferritin as iron overload markers in different underlying anemias before and after deferasirox treatment

Porter JB, El-Alfy M, Viprakasit V, Giraudier S, Chan LL, Lai Y, et al.

Eur. J. Haematol., 2016 Jan;96(1):19-26.
PMID: 25691036 DOI: 10.1111/ejh.12540

Plasma markers in addition to serum ferritin (SF) may be useful for the assessment of iron overload; however, predictive utility may differ depending on underlying, transfusion-dependent, anemias.

Matched MeSH terms: Ferritins/blood*
Hemophagocytosis in dengue: comprehensive report of six cases

Tan LH, Lum LC, Omar SF, Kan FK

J Clin Virol, 2012 Sep;55(1):79-82.
PMID: 22789140 DOI: 10.1016/j.jcv.2012.06.005

Hemophagocytic syndrome is a potentially fatal disorder. It is being increasingly reported but remained under-recognized in dengue. Most reported cases were in association with plasma leakage and shock but multi-organ impairment was also observed. We describe the time-lines of 6 cases of confirmed dengue with varying severities of hemophagocytosis. All had persistent fever, cytopenia and elevated transaminases with markedly elevated ferritin levels during and beyond the plasma leakage phase. Acute renal failure and central nervous system manifestation were observed in two patients. Morphological hemophagocytosis was demonstrated in three patients. All survivors showed clinical and biochemical resolution of hemophagocytosis indicating its transient nature. Persistence of fever and cytopenia together with multi-organ dysfunction, out of proportion to and beyond the plasma leakage phase should prompt clinicians to consider this phenomenon.

Matched MeSH terms: Ferritins/blood
Fulltext Growth velocity in transfusion dependent prepubertal thalassemia patients: results from a thalassemia center in Malaysia

Hamidah A, Arini MI, Zarina AL, Zulkifli SZ, Jamal R

Southeast Asian J. Trop. Med. Public Health, 2008 Sep;39(5):900-5.
PMID: 19058587

Growth impairment is commonly seen in children with thalassemia despite regular blood transfusions and desferrioxamine treatments. We investigated the growth velocity of 26 prepubertal patients with beta-thalassemia or HbE-beta thalassemia who were transfusion dependent aged between 2 and 13 years. The prevalence of impaired growth velocity (ie, growth velocity less than the third percentile) amongst the transfusion dependent prepubertal thalassemics was 57.7% compared to 19.2% in the control group. The mean height velocity of the thalassemics was 11.1% less than controls but this difference was not statistically significant (4.23cm/year vs 4.76cm/year, p = 0.08). The mean serum ferritin level of the thalassemics with a height < 3rd percentile was higher compared to those with a height > 3rd percentile (4,567.0 vs 2,271.0, p = 0.01). Our study showed that there was a high prevalence of impaired growth velocity amongst our transfusion dependent prepubertal thalassemics. This highlights the problem of inadequate chelation therapy, and compliance with chelation therapy amongst our patients. This study emphasizes the importance of monitoring growth parameters and optimal iron chelation therapy in these patients.

Matched MeSH terms: Ferritins/blood
Use of red blood cell indices for the identification of iron deficiency among blood donors

Nadarajan V, Sthaneshwar P, Eow GI

Transfus Med, 2008 Jun;18(3):184-9.
PMID: 18598281 DOI: 10.1111/j.1365-3148.2008.00862.x

The objective of this study was to identify haematological parameters useful in screening for iron deficiency among blood donors. Iron deficiency is a common complication of blood donation and often goes unrecognized until anaemia develops. Biochemical markers such as soluble transferrin receptor (TfR), ferritin and log(TfR/F) have been proposed as more valid indicators of body iron status. Red blood cell (RBC) parameters are, however, more easily measured and have also been proposed as indicators of iron depletion. We measured ferritin and TfR in 192 blood donors together with RBC analysis, performed on two haematology analysers. Thirteen donors had parameters suggestive of haemoglobinopathy and were excluded from further analysis. Overall, 10% (18/179) of the remaining donors had iron deficiency, as defined by log(TfR/F) exceeding the 95th percentile of the value in the population of first-time donors. Using receiver operating characteristic analysis, the sensitivity of ferritin was 100%, with a specificity of 90% at a cut-off of 15 mug L(-1). The sensitivity and specificity of RBC-Y at a cut-off of 152 for detecting iron deficiency were 81 and 89%, respectively. Haemoglobin content of reticulocytes, meanwhile, showed sensitivity of 69% and specificity of 93% when a cut-off of 28 pg was used. Both measures compare favourably with haemoglobin which only showed a sensitivity of 50%, although specificity was 91% at a cut-off value of 125 g L(-1). The parameter RBC-Y can be useful as a screening measure for iron deficiency in blood donors.

Matched MeSH terms: Ferritins/blood
An electronmicroscopic study of the interaction of Burkholderia pseudomallei and human macrophages

Nathan SA, Puthucheary SD

Malays J Pathol, 2005 Jun;27(1):3-7.
PMID: 16676686

B. pseudomallei has been shown to persist intracellularly in melioidosis patients until reactivated by decreasing immunocompetence. We have shown by transmission electron microscopy the internalization of B. pseudomallei by human macrophages via conventional phagocytosis enclosed within membrane-bound vacuoles or phagosomes. Ferritin labeled lysosomes provided evidence of phagosome-lysosome fusion. Ingested bacilli were designated as "intact" or "damaged" on the basis of their ultrastructural features. An intact bacterium was seen with low electron opaque central nuclear region surrounded by dense bacterial cytoplasm, bounded externally by bacterial plasma membrane and cell wall. In contrast, B. pseudomallei were considered damaged when seen with cavitation within the central nuclear region, separation of bacterial cytoplasm from the cell wall, herniation of cytoplasmic contents and lamination of bacterial cell wall and its surrounding electron transparent zone. Our observations indicate that the microbicidal mechanism(s) in B. pseudomallei-infected macrophages failed to ensure complete clearance of the organism and this failure probably facilitates intracellular persistence and proliferation, and this may be one of the survival strategies adopted by this organism.

Matched MeSH terms: Ferritins/immunology

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