Browsing by Author "LACERDA, R."
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- Growth hormone (GH)‐induced reconstitution of CD8+ CD28+ T lymphocytes in a rare case of severe lymphopenia associated with Juvenile Haemochromatosis and Turner's syndrome.Publication . PORTO, G.; CRUZ, E.; MIRANDA, H.; PORTO, B.; VASCONCELOS, J.; LACERDA, R.; ROETTO, A.; DARAIO, F.; BACELAR, C.Clin Endocrinol (Oxf). 2004 Oct;61(4):437-40. Growth hormone (GH)-induced reconstitution of CD8+ CD28+ T lymphocytes in a rare case of severe lymphopenia associated with Juvenile Haemochromatosis and Turner's syndrome. Porto G, Cruz E, Miranda HP, Porto B, Vasconcelos JC, Lacerda R, Roetto A, Daraio F, Bacelar C. Santo António General Hospital, Porto, Portugal. gporto@ibmc.up.pt Abstract This paper describes a rare case of Turner's syndrome associated with Juvenile Haemochromatosis and severe lymphopenia, followed-up for a period of 5 years. Because of the indication for treatment with growth hormone (GH), this case was observed as a model to analyse the effects of GH on growth, iron mobilization and lymphocyte reconstitution. For this purpose, a serial study of the T lymphocyte subpopulations CD4+, CD8+, CD8+ CD28+ and CD8+ CD28- was performed by immunophenotyping during the follow-up period. Besides the impact of both phlebotomy treatment and GH on the rapid growth and mobilization of 20.8 g of iron in 136 weeks, the most relevant observation was the finding of a significant expansion of CD8+ T lymphocytes expressing the costimulatory marker CD28 in the setting of the severe lymphopenia. These findings constitute new clinical evidence supporting the notion that the GH/IGF-1 system has an important role on the maintenance of T cell homeostasis in vivo, and that GH may be regarded as a putative therapeutic agent in T lymphocyte reconstitution. PMID: 15473875 [PubMed - indexed for MEDLINE]
- Low serum transferrin levels in HFE C282Y homozygous subjects are associated with low CD8(+) T lymphocyte numbers.Publication . MACEDO, M.F.; CRUZ, E.; LACERDA, R.; PORTO, G.; DE SOUSA, M.Blood Cells Mol Dis. 2005 Nov-Dec;35(3):319-25. Epub 2005 Sep 1. Low serum transferrin levels in HFE C282Y homozygous subjects are associated with low CD8(+) T lymphocyte numbers. Macedo MF, Cruz E, Lacerda R, Porto G, de Sousa M. SourceDivision of Human Genetics and Genetic Disorders, Iron Genes and the Immune System Laboratory, Institute for Molecular and Cell Biology (IBMC), Oporto, Portugal. Abstract Hereditary hemochromatosis (HH) is a genetic iron overload disease, in the majority of cases associated with homozygosity for the C282Y mutation of the HFE gene. In spite of this genetic homogeneity, there is a great clinical heterogeneity among HH patients. Low CD8(+) lymphocyte numbers have been associated with a more severe expression of iron overload in HH patients, and in experimental models of iron overload. HH patients present low serum transferrin levels. Transferrin is an indispensable resource for lymphopoiesis. Lymphocyte homeostasis follows general ecology rules of population dynamics that involve competition for limiting resources. In the present study, we questioned whether transferrin levels could be associated with the anomalies seen previously in lymphocyte subset numbers in HH patients. Transferrin levels, total and subset T lymphocyte counts were done in 426 apparently healthy subjects genotyped for HFE. All HFE C282Y carriers presented significantly lower serum transferrin levels than the wild type group, a difference that could not be explained solely by the degree of iron overload. Significant differences were also seen in transferrin levels between males and females, with females presenting higher average serum Transferrin levels. In the population of subjects with Transferrin levels lower than 248 mg/dl, a positive correlation was seen between the peripheral CD8(+) lymphocyte numbers and serum transferrin levels (R(2) = 2.41; r = 0.16; P = 0.018). To test the possible limiting resource effect of transferrin, the correlation between transferrin levels and CD8(+) lymphocyte numbers was scrutinized in 34 HH patients, homozygous for the C282Y mutation. In the homozygous males, where the lowest average transferrin levels were seen, another highly significant correlation was observed between Transferrin levels and CD8(+) numbers. This correlation points to a possible role of transferrin as a limiting resource for MHC class I dependent lymphocyte proliferation, an effect that was not observed in C282Y homozygous female patients. PMID: 16140024 [PubMed - indexed for MEDLINE]
- T cell numbers relate to bone involvement in Gaucher diseasePublication . LACERDA, L.; AROSA, F.A.; LACERDA, R.; CABEDA, J.; PORTO, G.; AMARAL, O.; Fortuna, A.; PINTO, R.; OLIVEIRA, P.; MCLAREN, C.E.; SA MIRANDA, C.; DE SOUSA, M.Blood Cells Mol Dis. 1999 Apr;25(2):130-8. T cell numbers relate to bone involvement in Gaucher disease. Lacerda L, Arosa FA, Lacerda R, Cabeda J, Porto G, Amaral O, Fortuna A, Pinto R, Oliveira P, McLaren CE, Sá Miranda C, de Sousa M. Department of Genetics Neurobiology, Porto University, Portugal. Abstract The major elements of bone pathology in Gaucher disease are a failure of osteoclast and osteoblast function, resulting in osteopenia and also osteonecrosis. T lymphocytes have recently been found to be involved in the regulation of osteoblast/osteoclast activity in vitro. In the present report the peripheral blood T major lymphocyte subsets were investigated in a group of genotyped type 1 Gaucher disease patients. A total of 31 patients were studied: 21 non-splenectomized (5 N370S homozygotes) and 10 splenectomized (of whom 1 was a N370S homozygote). The results show that non-splenectomized patients present a decrease in absolute numbers of peripheral blood T lymphocytes, specially the CD4+ T subset. However, when patients were analyzed with respect to the presence of bone disease, the number of CD8+ T lymphocytes was found to be statistically significantly lower in patients presenting bone involvement. Furthermore, lower numbers of CD8+ T lymphocytes were significantly correlated with higher levels of plasma tartrate resistant acid phosphatase (TRAP) activity, a putative marker of osteoclast cell activity. These in vivo findings are in agreement with the results reached in vitro by others. They provide an additional marker of disease severity in Gaucher disease. In the group of genotyped Gaucher disease patients, the majority of the N370S homozygous patients presented a clinically milder phenotype, including the absence of bone involvement, confirming earlier reports predicting that a number of these patients may remain undiagnosed. Collectively the homozygosity for the N370S mutation and normal T cell numbers may provide additional markers for the clinical heterogeneity of Gaucher disease. PMID: 10389595 [PubMed - indexed for MEDLINE