Detection of Trypanosoma cruzi and Treatment Monitoring by PCR from Dried Blood Spot Samples in Children.

BACKGROUND: Parasitic infections by Trypanosoma cruzi (T. cruzi) are frequent in children from endemic areas. Specific therapies have been successfully used in pediatric populations to treat this disease. T. cruzi diagnosis should be optimized and become available for any clinical environment. OBJECTIVE: To study T. cruzi prevalence in children from an area of active transmission and carry out a posttreatment follow-up. To verify the feasibility of detecting DNA of T. cruzi from dried blood spot. METHODS: We analyzed presence of T. cruzi in 78 Aboriginal children (Toba community) that attended to a rural school of Chaco province, Argentina. Serum and whole blood (dried blood spot) were assessed by means of serological techniques and PCR. Positive children received Benznidazole. Diagnosis and post treatment follow-up of T. cruzi infection were performed. RESULTS: The serology assay showed infection in 34 of 78 (43.5%) children studied; PCR was positive in 5/34, displaying parasitemia. Serology remained positive in 28/28 children 120 days post-treatment, while PCR was positive in 18/28 (6/34 children were lost in follow-up). No adverse effects during the treatment were reported. CONCLUSIONS: We were able to establish T. cruzi prevalence in the studied population and also to prove the usefulness of dried blood spot for T. cruzi detection using PCR in isolated areas. This method allowed us to verify early treatment failure. Possible causes of this failure are discussed below.

Splenic autoimplantation in omentum and stomach, hematoimmunological follow-up and B-cell repertoire in the graft.

INTRODUCTION: Splenic autoimplantation appears to be the only alternative to preserve splenic tissue after splenectomy; however, its relevance is still controversial We intended to study splenic autoimplantation in the greater omentum and stomach wall of rabbits and analyze its hematoimmunological performance and the preservation of original structures. METHODS: New Zealand rabbits were divided in two groups: autoimplanted (A) (n=13) and splenectomized (S) (n=4). The animals of group A underwent autoimplantation of splenic fragments in the greater omentum and gastric wall Both groups were evaluated by hemocytological tests, scintigraphy, immunoglobulin and C3 dosages, before the surgery and 2 and 4 months afterwards. After 4 months, the grafts were removed and histological examination and gen rearrangement of B-lymphocytes receptors by polymerase chain reaction (PCR) were performed to assess the cellular diversity of clones. RESULTS: The histological analysis demonstrated the presence of splenic tissue in 10 of the 13 cases (77%) with evident size reduction. The gastric location did not develop complications and demonstrated higher morphological correspondence to the autoimplanted tissue. Both groups showed significant decrease of IgM and increase of C3, without considerable differences between both of them during follow up. From the 8 grafts studied with PCR, 3 cases presented polyclonality and 5 oligoclonality. CONCLUSIONS: The revascularized grafts evidenced splenic regenerating tissue, probably associated to the oligoclonality detected by PCR. Consequently, we consider that autoimplantation is a reasonable alternative for splenectomized patients, even though the stomach placement and the high frequency of oligoclonality justify further investigation.