scholarly journals Evaluation of splenic accumulation and colocalization of immature reticulocytes and Plasmodium vivax in asymptomatic malaria: A prospective human splenectomy study

PLoS Medicine ◽  
2021 ◽  
Vol 18 (5) ◽  
pp. e1003632
Author(s):  
Steven Kho ◽  
Labibah Qotrunnada ◽  
Leo Leonardo ◽  
Benediktus Andries ◽  
Putu A. I. Wardani ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Peripheral Blood ◽  
Developmental Stages ◽  
Clinical Indication ◽  
Asymptomatic Malaria ◽  
Spleen Tissue ◽  
Asexual Stage ◽  
Parasite Survival ◽  
Total Body ◽  
Untreated Individuals

Background A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax. The mechanisms underlying this intense tropism are not clear. We hypothesised that immature reticulocytes, in which P. vivax develops, may display high densities in the spleen, thereby providing a niche for parasite survival. Methods and findings We examined spleen tissue in 22 mostly untreated individuals naturally exposed to P. vivax and Plasmodium falciparum undergoing splenectomy for any clinical indication in malaria-endemic Papua, Indonesia (2015 to 2017). Infection, parasite and immature reticulocyte density, and splenic distribution were analysed by optical microscopy, flow cytometry, and molecular assays. Nine non-endemic control spleens from individuals undergoing spleno-pancreatectomy in France (2017 to 2020) were also examined for reticulocyte densities. There were no exclusion criteria or sample size considerations in both patient cohorts for this demanding approach. In Indonesia, 95.5% (21/22) of splenectomy patients had asymptomatic splenic Plasmodium infection (7 P. vivax, 13 P. falciparum, and 1 mixed infection). Significant splenic accumulation of immature CD71 intermediate- and high-expressing reticulocytes was seen, with concentrations 11 times greater than in peripheral blood. Accordingly, in France, reticulocyte concentrations in the splenic effluent were higher than in peripheral blood. Greater rigidity of reticulocytes in splenic than in peripheral blood, and their higher densities in splenic cords both suggest a mechanical retention process. Asexual-stage P. vivax-infected erythrocytes of all developmental stages accumulated in the spleen, with non-phagocytosed parasite densities 3,590 times (IQR: 2,600 to 4,130) higher than in circulating blood, and median total splenic parasite loads 81 (IQR: 14 to 205) times greater, accounting for 98.7% (IQR: 95.1% to 98.9%) of the estimated total-body P. vivax biomass. More reticulocytes were in contact with sinus lumen endothelial cells in P. vivax- than in P. falciparum-infected spleens. Histological analyses revealed 96% of P. vivax rings/trophozoites and 46% of schizonts colocalised with 92% of immature reticulocytes in the cords and sinus lumens of the red pulp. Larger splenic cohort studies and similar investigations in untreated symptomatic malaria are warranted. Conclusions Immature CD71+ reticulocytes and splenic P. vivax-infected erythrocytes of all asexual stages accumulate in the same splenic compartments, suggesting the existence of a cryptic endosplenic lifecycle in chronic P. vivax infection. Findings provide insight into P. vivax-specific adaptions that have evolved to maximise survival and replication in the spleen.

scholarly journals Transient increase in circulating gamma/delta T cells during Plasmodium vivax malarial paroxysms.

1994 ◽  
Vol 179 (1) ◽  
pp. 311-315 ◽  
Author(s):  
M K Perera ◽  
R Carter ◽  
R Goonewardene ◽  
K N Mendis
Keyword(s):  
T Cells ◽  
Plasmodium Vivax ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Clinical Symptoms ◽  
Gastrointestinal Symptoms ◽  
Gamma Delta T Cells ◽  
Gamma Delta ◽  
Endemic Region ◽  
Gastrointestinal Pathology

The percentage of peripheral blood mononuclear cells (PBMC) bearing the CD3+ phenotype and the alpha/beta and gamma/delta T cell receptors (TCR) in PBMC were examined in Plasmodium vivax malaria patients and convalescents. The cells were labeled with monoclonal antibodies, stained with either fluorescence or phycoerythrin, and examined by ultraviolet (UV) microscopy. A highly significant increase in both the proportion and the absolute numbers of gamma/delta T cells (p < 0.005 and < 0.001, respectively, Student's t test) was observed in nonimmune P. vivax patients during clinical paroxysms compared to nonmalarial controls. These T cells, which normally constitute not more than 3-5% of PBMC, constituted < or = to 30% of PBMC during paroxysms in these nonimmune patients in whom the clinical symptoms were severe. A less significant increase of gamma/delta T cells were also observed in these nonimmune patients during infection, between paroxysms and during convalescence. In contrast, in an age-matched group of semi-immune patients resident in a malaria-endemic region of the country, in whom the clinical disease was comparatively mild, there was no increase in gamma/delta T cells either during infection, even during paroxysms, or convalescence. The severity of disease symptoms in patients as measured by a clinical score correlated positively with the proportion of gamma/delta T cells in peripheral blood (r = 0.53, p < 0.01), the most significant correlation being found between the prevalence and severity of gastrointestinal symptoms, nausea, anorexia, and vomiting, and the proportion of gamma/delta T cells (r = 0.49, p = 0.002). These findings suggest that gamma/delta T cells have a role to play in the pathogenesis of malaria, possibly in the general constitutional disturbances and particularly in gastrointestinal pathology in malaria.

scholarly journals The epidemiology and detectability of asymptomatic Plasmodium vivax and Plasmodium falciparum infections in low, moderate and high transmission settings in Ethiopia

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Elifaged Hailemeskel ◽  
Surafel K Tebeje ◽  
Sinknesh W. Behaksra ◽  
Girma Shumie ◽  
Getasew Shitaye ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasmodium Vivax ◽  
Age Groups ◽  
Diagnostic Tools ◽  
Asymptomatic Malaria ◽  
Rapid Diagnostics ◽  
Cross Sectional ◽  
Low Transmission ◽  
High Transmission ◽  
Study Sites

Abstract Background As countries move to malaria elimination, detecting and targeting asymptomatic malaria infections might be needed. Here, the epidemiology and detectability of asymptomatic Plasmodium falciparum and Plasmodium vivax infections were investigated in different transmission settings in Ethiopia. Method: A total of 1093 dried blood spot (DBS) samples were collected from afebrile and apparently healthy individuals across ten study sites in Ethiopia from 2016 to 2020. Of these, 862 were from community and 231 from school based cross-sectional surveys. Malaria infection status was determined by microscopy or rapid diagnostics tests (RDT) and 18S rRNA-based nested PCR (nPCR). The annual parasite index (API) was used to classify endemicity as low (API > 0 and < 5), moderate (API ≥ 5 and < 100) and high transmission (API ≥ 100) and detectability of infections was assessed in these settings. Results In community surveys, the overall prevalence of asymptomatic Plasmodium infections by microscopy/RDT, nPCR and all methods combined was 12.2% (105/860), 21.6% (183/846) and 24.1% (208/862), respectively. The proportion of nPCR positive infections that was detectable by microscopy/RDT was 48.7% (73/150) for P. falciparum and 4.6% (2/44) for P. vivax. Compared to low transmission settings, the likelihood of detecting infections by microscopy/RDT was increased in moderate (Adjusted odds ratio [AOR]: 3.4; 95% confidence interval [95% CI] 1.6–7.2, P = 0.002) and high endemic settings (AOR = 5.1; 95% CI 2.6–9.9, P < 0.001). After adjustment for site and correlation between observations from the same survey, the likelihood of detecting asymptomatic infections by microscopy/RDT (AOR per year increase = 0.95, 95% CI 0.9–1.0, P = 0.013) declined with age. Conclusions Conventional diagnostics missed nearly half of the asymptomatic Plasmodium reservoir detected by nPCR. The detectability of infections was particularly low in older age groups and low transmission settings. These findings highlight the need for sensitive diagnostic tools to detect the entire parasite reservoir and potential infection transmitters.

Congenital Malaria: A Rare Cause of Splenomegaly and Anemia in an American Infant

PEDIATRICS ◽  
1977 ◽  
Vol 60 (2) ◽  
pp. 209-212
Author(s):  
D. Thompson ◽  
C. Pegelow ◽  
A. Underman ◽  
D. Powars
Keyword(s):  
Plasmodium Vivax ◽  
Hemolytic Anemia ◽  
Peripheral Blood ◽  
Endemic Area ◽  
Blood Smear ◽  
Clinical Manifestations ◽  
Peripheral Blood Smear ◽  
Pregnancy Malaria ◽  
Congenital Malaria

A 38-day-old infant had fever, jaundice, hepatosplenomegaly, and a hemolytic anemia. A peripheral blood smear demonstrated intraerythrocytic malarial parasites identified as Plasmodium vivax. Maternal and infant sera contained antibodies to this species. A directed history revealed the mother had suffered several febrile illnesses in Mexico during her pregnancy. Malaria had not been diagnosed nor was it considered at the time of her delivery at this hospital. Review of this and six other cases of congenital malaria reported in this country since 1950 indicates clinical manifestations seldom appear before 3 weeks of age. Although these signs are more frequently associated with other transplacental infections, their occurrence in an infant whose mother is from or who has traveled in an endemic area should prompt consideration of the diagnosis of congenital malaria.

Exflagellating Plasmodium vivax in Peripheral Blood

2003 ◽  
Vol 127 (1) ◽  
pp. 117-118
Author(s):  
Jason C. Ford ◽  
Louis D. Wadsworth
Keyword(s):  
Plasmodium Vivax ◽  
Peripheral Blood

scholarly journals Bone Marrow and Peripheral Blood Cells Toxicity of a Single 2.0 Gy Cobalt60 Ionizing Radiation: An Animal Model

1970 ◽  
Vol 29 (2) ◽  
Author(s):  
Shittu Akeem ◽  
Olatunbosun Lukman ◽  
Khalil Eltahir ◽  
Olalere Fatai ◽  
Babatunde Abiola ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Marrow Cell ◽  
P Value ◽  
Peripheral Blood Cells ◽  
P Values ◽  
Cell Parameters ◽  
Post Irradiation ◽  
Total Body

BACKGROUND: Bone marrow is extremely vulnerable to damage caused by radiation therapy. Hence, bone marrow suppression is an important side effect of radiotherapy. Effective use of radiotherapy is therefore compromised by radiation-related injuries.MATERIAL AND METHODS: Six Guinea-pigs were recruited for the study of which three were subjected to total body irradiation with Co60 while the other three served as controls. Bone marrow and peripheral blood samples were collected before and at days 9, 14 and 21, post irradiation. Manual and automated counts were performed for bone marrow nucleated cells and peripheral blood cells respectively.RESULTS: Declining bone marrow cellularity was evident immediately post irradiation. Mean ± SD of marrow cell counted per mm3 were 121,924±281, 87,603±772, 121,367±375 and122,750±1000 pre-irradiation and days 9, 14 and 21, postirradiation (p-values 0.10, 0.27 and 0.29 respectively). Significant drops in counts were noticed on day 9 post-irradiation for all red cell parameters (p-values <0.05), for Total White Blood Cell Count and Neutrophil count (p-values <0.05) and also on days 14 and 21 for Lymphocytes (p-values <0.05) and on day 21 for Eosinophil/Basophil/Monocytes (p-value <0.05). A significant drop in platelets counts was also noticed on day 9 (p-value <0.05) which significantly increased above pre-irradiation value on day 21.CONCLUSION: Total body irrradiation with Co60 significantly affects the bone marrow with maximum reductions in marrow nucleated cells and peripheral blood cells counts on day 9 post irradiation. 

Result of attempted hematopoietic reconstitution using isologous, peripheral blood mononuclear cells: a case report

Blood ◽  
1980 ◽  
Vol 56 (3) ◽  
pp. 516-520 ◽  
Author(s):  
RA Abrams ◽  
D Glaubiger ◽  
FR Appelbaum ◽  
AB Deisseroth
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Identical Twin ◽  
Peripheral Blood Mononuclear ◽  
Similar Treatment ◽  
Hematopoietic Recovery ◽  
Hematopoietic Reconstitution ◽  
Blood Mononuclear Cells ◽  
Total Body

Abstract In order to test the effect of peripheral blood mononuclear cell infusions on hematopoietic recovery in man we intensively leukapheresed a normal identical twin and obtained 9.8 x 10(10) peripheral blood mononuclear cells containing 4 x 10(5) CFU-C. These isologous cells were infused into his identical twin brother who had received 150 rad of total body irradiation and intensive combination chemotherapy as adjuvant therapy for Ewing's sarcoma. When compared to other patients receiving similar treatment, leukocyte recovery was accelerated by 3–4 wk, and occurred at a rate comparable to that induced by infusion of autologous cryopreserved marrow. Recovery of granulocytes, monocytes and platelets was not accelerated. The low number of CFU-C present in the preparation used ((one-eighth the number of CFU-C we usually obtain from bone marrow autograft collections) may have led to the pattern of hematopoietic recovery we observed in this patient.

Apical membrane protein 1‐specific antibody profile and temporal changes in peripheral blood B‐cell populations in Plasmodium vivax malaria

2019 ◽  
Vol 41 (9) ◽  
Author(s):  
Roberta Reis Soares ◽  
Clarissa F. Cunha ◽  
Raquel Ferraz‐Nogueira ◽  
Alessandro Marins‐dos‐Santos ◽  
Rodrigo Nunes Rodrigues‐da‐Silva ◽  
...  
Keyword(s):  
Membrane Protein ◽  
B Cell ◽  
Plasmodium Vivax ◽  
Specific Antibody ◽  
Peripheral Blood ◽  
Vivax Malaria ◽  
Apical Membrane ◽  
Temporal Changes ◽  
Cell Populations ◽  
Plasmodium Vivax Malaria
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