chondroitin-sulfates and Anemia

Vitamin A supplementation is believed to enhance immune responses to infection but few studies have assessed its effects on anti-malarial immunity, especially during pregnancy when women are at increased risk from both vitamin A deficiency and pregnancy-associated malaria. The pathological effects of malaria in pregnancy are believed to be due to the sequestration of parasites in the placenta mediated via binding of variant surface antigens (VSA) expressed on the surface of P. falciparum infected red blood cells to placental chondroitin sulphate A (CSA).. We conducted a randomized double-blind controlled trial of vitamin A supplementation in 98 primigravid Ghanaian women to investigate the effects of vitamin A supplementation on levels of IgG antibodies binding to VSA of a clinical, P. falciparum placental isolate and to two isolates selected (or not) for adherence to CSA in vitro (anti-VSACSA IgG or anti-VSA IgG). Placental malarial infection was determined by placental blood smear and histology.. Vitamin A supplementation was non-significantly associated with a decreased risk of active or chronic-active placental malarial infection compared to past, resolved infection at delivery, as determined by histology (OR=0.42, P=0.13--adjusted for level of education). After adjustment for differences in baseline values, levels of anti-VSACSA IgG to a placental, CSA-adherent isolate (EJ-24) but not to two isolates selected for CSA-adhesion in vitro (FCR3CSA and BusuaCSA), were significantly lower in women receiving vitamin A supplementation than in women receiving placebo (P=0.002). There was no apparent effect of vitamin A supplementation to levels of Ab to non-CSA-adherent parasite isolates.. The data suggest that the reduction in the levels of anti-VSACSA antibodies to the known placental malaria isolate may reflect reduced intensity or duration of placental parasitaemia in women receiving vitamin A supplementation. These observations are of potential public health significance and deserve further investigation.

Topics: Adult; Anemia; Antibodies, Protozoan; Antigens, Surface; Chondroitin Sulfates; Dietary Supplements; Double-Blind Method; Female; Ghana; Gravidity; Humans; Immunoglobulin G; Malaria, Falciparum; Placenta Diseases; Pregnancy; Pregnancy Complications, Parasitic; Risk Factors; Vitamin A; Vitamin A Deficiency

Plasmodium vivax can potentially lead to life-threatening episodes but the mechanisms underlying severe disease remain poorly defined. Cytoadhesion of infected erythrocytes may contribute to P. vivax sequestration and organ injury although its physiological impact is still unknown. Here, we aimed to describe clinically-relevant cytoadhesive phenotypes of P. vivax isolates.. Rosetting and adhesion to CSA, CD36, ICAM1, placental and brain cryosections were determined in P. vivax peripheral isolates from 12 pregnant women, 24 non-pregnant women and 23 men from Manaus (Brazil). P. falciparum co-infection was excluded by PCR and P. vivax isolates were genotyped by assessing the size polymorphism of microsatellites ms2, ms20 and msp1F3 through capillary electrophoresis of PCR products. P. vivax monoinfection was confirmed by PCR in 59 isolates, with 50 (85%) of them being single-clone infections. One P. vivax haplotype was more frequently found among pregnant women (33%) than in non-pregnant women (0%) and men (4%; p=0.010). Rosetting was observed in 64% of the isolates, adhesion to CSA in 15%, to ICAM1 in 12% and to placental cryosections in 9%, being similar among pregnant and non-pregnant groups. Intensity of rosetting was higher among anaemic individuals compared to non-anaemic (p=0.010) and decreased with increasing haematocrit (p=0.033) and haemoglobin levels (p=0.015).. P. vivax peripheral isolates from pregnant women do not exhibit a prominent adhesion to CSA, although other parasite phenotypes still unknown may increase the propagation of certain P. vivax clones observed among pregnant hosts. Rosetting is a frequent cytoadhesive phenotype in P. vivax infections that may contribute to the development of anaemia.

Topics: Adult; Anemia; Brain; Brazil; CD36 Antigens; Cell Adhesion; Chondroitin Sulfates; Female; Genotype; Humans; In Vitro Techniques; Intercellular Adhesion Molecule-1; Male; Middle Aged; Placenta; Plasmodium vivax; Polymerase Chain Reaction; Pregnancy; Young Adult

The severe adverse events observed in patients who received hemoglobin based oxygen carriers (HBOCs) were associated with the Ringer's D.L lactate resuscitative solution administered and to the excipient used in the HBOCs containing Ringer's D,L lactate and the length of storage of the preserved RBC administered to the patient at the time that the HBOCs were infused. This paper reports the quality of the red blood cells preserved in the liquid state at 4 degrees C and that of previously frozen RBCs stored at 4 degrees C with regard to their survival, function and safety. Severe adverse events have been observed related to the length of storage of the liquid preserved RBC stored at 4 degrees C prior to transfusion. The current methods to preserve RBC in the liquid state in additive solutions at 4 degrees C maintain their survival and function for only 2 weeks. The freezing of red blood cells with 40% W/V glycerol and storage at -80 degrees C allows for storage at -80 degrees C for 10 years and following thawing, deglycerolization and storage at 4 degrees C in the additive solution (AS-3, Nutricel) for 2 weeks with acceptable 24 hour posttransfusion survival, less than 1% hemolysis, and moderately impaired oxygen transport function with no associated adverse events. Frozen deglycerolized RBCs are leukoreduced and contain less than 5% of residual plasma and non-plasma substances. Frozen deglycerolized RBCs are the ideal RBC product to transfuse patients receiving HBOCs.

Topics: 2,3-Diphosphoglycerate; Adenine; Adenosine Triphosphate; Anemia; Blood Preservation; Blood Substitutes; Blood Transfusion, Autologous; Cell Survival; Chondroitin Sulfates; Citrates; Complex Mixtures; Dextrans; Erythrocytes; Gentamicins; Glucose; Hemoglobins; Hemolysis; Humans; Mannitol; Sodium Chloride; Temperature; Time Factors

Cytoadherence of Plasmodium falciparum-infected erythrocytes to the microvascular endothelium is believed to be a key factor in the development of cerebral malaria. Erythrocyte rosette formation has been correlated with malaria severity in studies from east and west Africa. We cultured fresh isolates from Malawian children with severe (n = 76) or uncomplicated (n = 79) malaria to pigmented trophozoite stage and examined rosette formation and adherence to CD36, intercellular adhesion molecule-1 (ICAM-1), chondroitin sulfate A (CSA), and thrombomodulin (TM). Most (126 of 148) isolates bound to CD36, and 76 of 136 bound to ICAM-1. Fewer bound to CSA (40 of 148) or TM (23 of 148). After controlling for parasitemia, there was an inverse association between binding to CD36 (P = 0.004) or ICAM-1 (P = 0.001) and disease severity. Parasites from children with severe malaria anemia bound least to CD36, whereas ICAM-1 binding was lowest in children with cerebral malaria. There was no difference in rosette formation between any of the groups. In Malawian children, there was no evidence of a positive association between adherence to any of the receptors examined and disease severity. The negative association found raises the possibility that adherence to certain receptors could instead be an indicator of a less pathogenic infection.

Topics: Anemia; Animals; CD36 Antigens; Cell Adhesion; Child; Child, Preschool; Chondroitin Sulfates; Erythrocytes; Humans; Infant; Intercellular Adhesion Molecule-1; Malaria, Cerebral; Malaria, Falciparum; Malawi; Plasmodium falciparum; Rosette Formation; Severity of Illness Index; Thrombomodulin

Topics: Administration, Oral; Adult; Aged; Anemia; Anemia, Hypochromic; Chondroitin; Chondroitin Sulfates; Female; Ferritins; Humans; Male; Middle Aged; Renal Dialysis