Alteración de la distribución de subpoblaciones T en la sangre periferica de pacientes con anemia severa idiopática. / [Changes in distribution of T subpopulations in the peripheral blood of patients with severe idiopathic anemia]

The following immunological studies were performed in circulating mononuclear cells of 17 patients with severe aplastic anemia (SAA): a) lymphocytic phenotypes; b) proliferative response to PHA; c) determination of interleukin 2 (IL2) production and d) expression of Tac CD25. Fifteen of the seventeen patients showed altered CD4/CD8 regulatory populations, expressed as a significantly diminished CD4/CD8 ratio (0.72 +/- 0.19, NV: 1.8 +/- 0.6) (Table 1). The proliferative response to PHA was normal in 80

of the cases; only 2 of the patients showed a diminished response to the mitogen (Fig. 1). IL2 production by PHA-stimulated mononuclear cells was significantly increased (56.6 +/- 9.8; NV: 11 +/- 7.69) (Fig. 1), and a deficient expression to CD25 antigen was also recorded (Table 2). In the other two patients, we observed a normal CD4/CD8 ratio (Table 1, patients 1 and 2) with absence of proliferative response to PHA and hypo-production of IL2 (Fig. 1). These results suggest that in these two cases the hematopoietic defect could be associated to a primary deficiency of cellular immunity. Our results support the current concept of diversity of pathogenetic mechanisms implicated in SAA, and suggest that there are groups of patients with variable degrees of immunological defect that can be delineated through laboratory assays. On the other hand, the altered distribution of regulatory populations mostly due to an absolute decrease of the CD4 subpopulation, associated to the hyperproduction of IL2 and deficient expression of the Tac antigen in most of our patients, suggest the existence of functional alterations.

Estudios linfocitarios, fenotípicos y funcionales en inmunodeficiencias primarias. / [Lymphocytic, phenotypic and functional studies in primary immunodeficiencies]

In this report we present the leukocyte phenotypic analysis of 64 cases of primary immune deficiencies (PID). Functional studies related to lymphocyte activation (CD25 (Tac) antigen expression and response to exogenous IL2) as well as immunoregulatory pathways (spontaneous suppressor activities and suppression by soluble factors) were also considered taking immunodeficiency with hyper-IgM (IDHM) as model. The study of mononuclear cell populations with monoclonal antibodies allowed the characterization of defined phenotypes. In common variable immunodeficiency, B cells were present in normal percentages. In sex-linked agammaglobulinemia there was a lack of B lymphocytes and normal distribution of regulatory populations. These results point out the difference between these two entities despite their clinical and infective similarities. Excess of cells expressing CD38 antigen (NV: 4 +/- 2) were found in: predominantly cell mediated immunodeficiency (PCMI): 38 +/- 20; ataxia telangiectasia: 25 +/- 8, hyper-IgE syndrome: 24 +/- 13; Di George syndrome (DGS): 24 +/- 9, chronic mucocutaneous candidiasis: 15 +/- 7. The increased expression of this antigen was correlated with the presence of compromised cellular immunity. The DGS presented the lowest level of CD8 cells (6 +/- 5; NV: 21 +/- 7). In two patients with IDHM, the phenotypic profile was similar to that found in PCMI (low CD3 cells, low CD4/CD8 ratio and elevated CD38 cells). The depressed proliferative response to PHA demonstrates a cellular immune defect. In both patients we found a low expression of CD25 antigen in stimulated cells. Moreover, the addition of exogenous IL2 decreased the proliferative response to PHA in a dose-dependent fashion, suggesting that the cells expressing the CD25 antigen have suppressor capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis autoinmune en niños. Presentación inicial como falla hepática fulminante. / [Autoimmune hepatitis in children. Initial presentation as fulminant hepatic failure]

There are few cases reported of autoimmune hepatitis (AIH) type 2 presenting as fulminant hepatic failure (FHF) in children. The purpose of this study was to report three girls with AIH type 2 that presented as FHF. METHODS: Over a period of 12 years, 123 patients with AIH diagnosed based on international criteria, 9 (7

) were type 2.3 of them presented as FHF. Other etiologies (viral, metabolic and toxic) were ruled out. The treatment was started with prednisone (2 mg-kg-day) and azathioprine (2 mg-kg-day). EVOLUTION: Patients 1 and 3 died while waiting for liver transplant (LT) at 72 and 48 hours after initiating medical treatment. Patient 2 underwent LT3 days after starting treatment, with excellent evolution at 3 years and 7 months of follow up. CONCLUSIONS: 1--AIH type 2 was very infrequent in our group. 2--33

of cases had initial presentation as FHF. 3--The course of the disease was aggressive, not responding to immunosuppressive therapy. The evolution was unfavorable in all patients. 4--LT is an alternative treatment for this severe disease.