Berta Valverde

Visceral Leishmaniasis in Costa Rica: First Case Report

We describe a 15-month-old eutrophic immunocompetent male who presented with fever, hepatosplenomegaly, pancytopenia, and hypergammaglobulinemia. Leishmania amastigotes were identified in spleen and bone marrow specimens. In addition, tissue culture, animal inoculation, and isoenzyme analysis identified the parasite as Leishmania donovani infantum or Leishmania donovani chagasi. The infant was successfully treated with an antimonial drug. These findings represent the first case of visceral leishmaniasis reported in Costa Rica.

Molecular and epidemiologic findings of childhood acute leukemia in Costa Rica.

In Central America, nearly 70% of pediatric cancer is related to hemato-oncologic disorders, especially acute lymphoblastic leukemia (ALL). Preliminary studies have described a high incidence of childhood leukemia in these countries; however, no molecular analyses of these malignancies have yet been carried out. We studied diagnostic samples from 84 patients from the National Childrens Hospital in San Jose, Costa Rica (65 precursor B-ALL, 5 T-cell ALL, and 14 acute myeloblastic leukemia). Our methodology included cytogenetic, fluorescent in situ hybridization, and polymerase chain reaction approaches. The observed rate of leukemia was 52.2 cases per million children per year. Twelve out of 65 (18.4%) precursor B-ALL tested positive for TEL-AML1 and 3 cases for BCR-ABL (4.6%). In addition, we detected 2 patients carrying an E2A-PBX1 transcript (3.1%) and 1 patient with an MLL-AF4 fusion gene (1.5%). None of the T-cell ALL cases were positive for either SIL-TAL1 or HOX11L2. Within 14 acute myeloblastic leukemia patients, we confirmed 2 cases with FLT3-internal tandem duplication+, 1 patient with AML1-ETO, and only 1 case carrying a PML-RARα rearrangement. The present study confirms the relatively high incidence of pediatric leukemia in Costa Rica and constitutes the first report regarding the incidence of the main molecular alterations of childhood leukemia in our region.

Hemoglobin Perth in Costa Rica

To the Editor: Unstable hemoglobins are characterized by intracellular precipitation of hemoglobin that leads to inclusion body formation. Those patients usually present with congenital syndrome that includes hemolytic anemia during infancy. Clinical features show a high variability in almost all affected individuals at any age [1,2]. A 3 years and 9-month-old male presented with acute hemolytic anemia and jaundice from age 2 years. The initial cell blood count showed normal leucocytes and platelet counts, a hemoglobin of 4.9 g/dl, MCVof 88.3 fl, MCH of 22.9 pg and reticulocyte count of 58% uncorrected. Red cell morphology showed marked anisopoikilocytosis. Inclusion body formation was found in peripheral blood smears after incubation at 378C with supravital staining. Hemoglobin electrophoresis on cellulose acetate showed an HbA2 of 5.6% and fetal hemoglobin of 2.9%. As the parents and siblings never presented with anemia, jaundice, splenomegaly, or an abnormal hemoglobin electrophoretic pattern, b-thalassemia diagnosis was not considered and the patient was classified as having a non-immune hemolytic anemia (NIHA). However, because the patient’s condition did not fit a classic NIHA, a new hemoglobin electrophoresis was performed using fresh hemolysate; a previously unnoticed slow band near the origin was observed. We considered other diagnostic possibilities, such as the most frequent slow hemoglobins: A2 or Constant Spring. As the former has normal erythrocyte morphology without clinical features, Constant Spring was considered more likely, mainly because such patients have normal or slightly high values of MCV like in our patient. The slow band found in the hemoglobin electrophoresis prompted us to do an HPLC analysis. That analysis discarded Constant Spring. The a1, a2, and b-chain globins genes were amplified by PCR and the amplicons purified in order to find mutations in the direct nucleotide sequence. A multiplex gap-PCR test for a-chain globin genes deletions of the rightward ( a 3.7) and the leftward ( a 4.2) were negative. All those tests confirmed that the patient was heterozygous for hemoglobin Perth (codon 32 CTG>CCG or Leu32Pro). We believe this is a de novo mutation because parents and siblings of the propositus are clinically normal. De novo mutation has been reported as being common [3]. At present, our patient requires monthly transfusions of packed red cells and he is receiving hydroxyurea. Carriers of Perth hemoglobin usually show improvement in their clinical features with transfusion therapy [4] although other treatment approaches, including partial splenectomy, may be considered [5].