The present study evaluated the effects of infected culture supernatant of erythrocytes, fractionation of culture supernatant and serum from dogs infected with Babesia gibsoni (B. gibsoni) on the maturation of canine reticulocytes in vitro. The SDS-PAGE demonstrated that significantly broader bands were generated by both the infected culture supernatant of erythrocytes and the serum from dogs chronically infected with B. gibsoni. The culture supernatant of erythrocytes infected with B. gibsoni strongly suppressed the maturation of reticulocytes. Prior studies showed that chronically infected serum had inhibitory effects on both the maturation of reticulocytes and the canine pyrimidine 5'-nucleotidase subclass I and purine-specific 5'-nucleotidase activity. In addition, serum free infected culture supernatant of erythrocytes had an inhibitory effect on the morphological maturation of reticulocytes. These results suggest that infected serum and culture supernatant of erythrocytes might accumulate excess proteins and/or metabolites as a result of the inhibited maturation of reticulocytes and decreased activity of erythrocyte 5'-nucleotidase. Furthermore, the fractions observed at >150 kDa- and 150-70 kDa- in the infected culture supernatant and serum retarded the maturation of canine reticulocytes in vitro. The results obtained from the in vitro examinations, in the present study, suggested that B. gibsoni itself and/or its metabolites might release certain proteins in the infected culture supernatant and serum from infected dogs and as a result delay morphological maturation of canine reticulocytes.
Animals ; Babesia/*immunology ; Babesiosis/blood/immunology/parasitology/*veterinary ; Cell Differentiation/immunology ; Dog Diseases/*blood/immunology/*parasitology ; Dogs ; Electrophoresis, Polyacrylamide Gel ; Erythrocytes/*immunology ; Reticulocytes/*immunology

OBJECTIVETo determine whether affected reticulocytes could be a reliable marker for the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH), we analyzed CD59-antigen expression on the membranes of reticulocytes and erythrocytes.

METHODSWe studied 10 PNH patients and 5 healthy volunteers by two-color flow cytometry with a membrane permeable fluorescent dye, thiazole orange (TO), and anti-CD59 monoclonal antibodies (MoAb). TO was introduced to gate reticulocytes and anti-CD59 MoAb were used to identify glycosylphosphatidylinositol (GPI)-deficient cells.

RESULTSCells from healthy individuals were only CD59 positive. However, in all PNH patients, CD59-antigen expression could be divided into 3 types: type I cells (CD59 normally positive), type II cells (CD59 partly positive) and type III cells (CD59 negative). The majority of reticulocytes belonged to type III cells, GPI-deficient cells (61.0%). In addition, the percentage of affected reticulocytes was higher than that of erythrocytes.

CONCLUSIONSAnalyzing PNH reticulocytes was important, because most patients had elevated numbers of reticulocytes, which represent more closely the recent erythroid output of BM. However, circulating mature erythrocytes were subject to complement-mediated intravascular lysis. Therefore, the percentage of abnormal erythrocytes may not accurately reflect the proliferation rate of normal and abnormal erythroid progenitor cells. Thus, affected reticulocytes could be a more reliable indicator for the diagnosis of PNH than mature erythrocytes.

Adult ; CD59 Antigens ; analysis ; Erythrocyte Count ; Erythrocytes ; cytology ; immunology ; Female ; Flow Cytometry ; Hemoglobinuria, Paroxysmal ; immunology ; Humans ; Immunophenotyping ; Male ; Middle Aged ; Reticulocytes ; cytology ; immunology

Plasmodium falciparum can invade all stages of red blood cells, while Plasmodium vivax can invade only reticulocytes. Although many P. vivax proteins have been discovered, their functions are largely unknown. Among them, P. vivax reticulocyte binding proteins (PvRBP1 and PvRBP2) recognize and bind to reticulocytes. Both proteins possess a C-terminal hydrophobic transmembrane domain, which drives adhesion to reticulocytes. PvRBP1 and PvRBP2 are large (> 326 kDa), which hinders identification of the functional domains. In this study, the complete genome information of the P. vivax RBP family was thoroughly analyzed using a prediction server with bioinformatics data to predict B-cell epitope domains. Eleven pvrbp family genes that included 2 pseudogenes and 9 full or partial length genes were selected and used to express recombinant proteins in a wheat germ cell-free system. The expressed proteins were used to evaluate the humoral immune response with vivax malaria patients and healthy individual serum samples by protein microarray. The recombinant fragments of 9 PvRBP proteins were successfully expressed; the soluble proteins ranged in molecular weight from 16 to 34 kDa. Evaluation of the humoral immune response to each recombinant PvRBP protein indicated a high antigenicity, with 38-88% sensitivity and 100% specificity. Of them, N-terminal parts of PvRBP2c (PVX_090325-1) and PvRBP2 like partial A (PVX_090330-1) elicited high antigenicity. In addition, the PvRBP2-like homologue B (PVX_116930) fragment was newly identified as high antigenicity and may be exploited as a potential antigenic candidate among the PvRBP family. The functional activity of the PvRBP family on merozoite invasion remains unknown.
Epitopes, B-Lymphocyte/*chemistry/genetics/*immunology ; Female ; Humans ; Immunodominant Epitopes/chemistry/genetics/*immunology ; Malaria, Vivax/immunology/*parasitology ; Middle Aged ; Plasmodium vivax/chemistry/genetics/*immunology ; Protein Structure, Tertiary ; Protozoan Proteins/chemistry/genetics/*immunology ; Reticulocytes/*parasitology

PURPOSE: The annual incidence of aplastic anemia (AA) in Asian countries is higher than in Western countries. The pathogenesis in AA has been investigated in hematopoiesis and immunology. Recently, the survival rate and the quality of life of the patients with AA have been steadily improved by the development of a variety of treatments such as the immunosuppressive therapy (IST), and hematopoietic stem cell transplantation (HSCT). The Korean Society of Pediatric Hematology-oncology retrospectively investigated the incidence, treatment strategies, survival rate, and time to become independent from transfusion in patients with AA, who were diagnosed from January 1st, 1991 to December 31st, 2000 in Korea. METHODS: All the questionnaires were sent to a group of training hospitals, and we collected about 600 questionnaire forms from 27 hospitals. However, 493 reports were available for data analysis. RESULTS: The male and female ratio in AA is 1.1 (259 males vs. 234 female). The median age at diagnosis is 9 years old (range; 0.8~16 years old). The annual incidence of children with AA in Korea is 4.5 per million on the basis of Korean pediatric population. In etiology, there are 20 cases (4.1%) in congenital and others in acquired AA. In acquired AA, the cause of illness was not identifiable for most of the patients, but 1 patient had hepatitis-associated AA, and 3 patients developed the illness after medication. According to the initial laboratory data at diagnosis, the peripheral blood findings showed that hemoglobin is 7.1+/-2.4 g/dL, white blood cell 3, 200/microL (200~16, 550), absolute neutrophil counts 670/microL (0~12, 487), platelets 19, 000/microL (1, 000~500, 000), and corrected reticulocytes 0.18% (0.0~4.7). The bone marrow examination revealed that cellularity was below 25% in 348 patients, and over 25% in 105 patients. In the available data, 269 patients (54.6%) were diagnosed of severe aplastic anemia (SAA) and 224 patients of non-SAA (NSAA). HSCT were done for 96 patients (19.5%) and others received another treatments such as the IST. The anti-thymocyte globulin (ATG) or anti-lymphocyte globulin (ALG) treatment was done for 263 cases, corticosteroids for 259, cyclosporine A (CSA) for 215, and anabolic steroids for 138. The combination IST including ATG or ALG plus corticosteroid plus CSA were applied to 154 children with AA, and transfusion only in 37, as conservative care. In case of those patients with HSCT, the time from diagnosis to transplantation was 12 months (1~144 months) and the sources of stem cells were bone marrow in 82 cases, growth factor mobilized peripheral blood in five, and cord blood in six. There were 57 patients transfused below 40 units of blood products before HSC transplantation. Graft rejection was identified from 16 patients, and booster transplantations were done for 12 patients among them. In complications of HSCT, the graft versus host disease was developed in 20 patients and viral diseases in 12 cases including the CMV, herpetic infection, and hepatitis. Also, one patient suffered from veno-occlusive disease. The overall survival rate in children with AA is 64.3%. The survival rate in HSCT is better than that IST (76.9% vs. 62.6%, P< 0.05). In IST, overall survival rate in very SAA showed lower than SAA and NSAA, and in SAA lower than NSAA in case of absolute neutrophil count below 200/microL (P< 0.05). There was no significant difference in terms of the sex, age at beginning of treatment. In HSCT, transfusion was not related to the survival rate. However, overall survival rate is better in short interval between diagnosis and HSCT than in long interval (P< 0.05). There was no significant difference in the probability of transfusion independence according to treatment strategies, even though it was 71.0% in HSCT and 12.8% in immunosuppressive therapy at the end point of survey (P=0.47). The response pattern was as follows. There were 155 cases of complete response, 110 of partial response and 120 of no response in spite of various treatments. The relapse after treatment was found in 11 patients after IST, of which 6 patients experienced more than 2nd relapse. The median time between the end of treatment and relapse was 16 months (6~84 months). Only three cases developed into other diseases (1 case into acute myeloid leukemia and 2 cases into myelodysplastic syndrome). The median time from diagnosis to the end of treatment was 62 months (0.5~174 months). In fatal cases, the median time between diagnosis and death was 29 months (0~144 months) despite several therapeutic strategies. CONCLUSION: In Korea, the annual incidence of children with AA is 4.5 per million. This result is similar to the ones reported in other Asian countries, but higher than those in Western countries. Although a lot of children with AA received various therapies including IST or HSCT, new treatment strategies have to be developed to improve the survival rate and the quality of life of children with AA
Adrenal Cortex Hormones ; Allergy and Immunology ; Anemia, Aplastic* ; Antilymphocyte Serum ; Asian Continental Ancestry Group ; Bone Marrow ; Bone Marrow Examination ; Child* ; Cyclosporine ; Diagnosis ; Epidemiology* ; Female ; Fetal Blood ; Graft Rejection ; Graft vs Host Disease ; Hematopoiesis ; Hematopoietic Stem Cell Transplantation ; Hepatitis ; Humans ; Incidence ; Korea* ; Leukemia, Myeloid, Acute ; Leukocytes ; Male ; Neutrophils ; Quality of Life ; Surveys and Questionnaires ; Recurrence ; Reticulocytes ; Retrospective Studies* ; Statistics as Topic ; Stem Cells ; Steroids ; Survival Rate ; Virus Diseases