Secondary prophylaxis with rFVIIa in hemophilia and inhibitors: recommendations from an experts committee from Argentina.

Secondary prophylaxis with rFVIIa has been the subject of several publications in the past few years. However, there is no general consensus on how this treatment should be put into practice, as publications have been very heterogeneous in the dosing schedule they report. Furthermore, the mechanism of action of rFVIIa and its short half life have been used as arguments against its role in prophylaxis. There have been a series of recent publications that show that rFVIIa can traffic through the intact endothelium and be stored in the subendothelium of several organs for a prolonged period of time. In order to consensuate the role of rFVIIa in prophylaxis, a group of experts from Argentina, resumed available information regarding pharmacology and clinical experience with this treatment, and developed a series of recommendations to use this drug in the prophylaxis setting.

[AIDS related lymphomas: Histopathological subtypes and association with Epstein Barr virus and Human Herpes virus type-8]. / Linfomas asociados con la infección por el virus de la inmunodeficiencia humana: subtipos histológicos y asociación con los virus de Epstein Barr y Herpes-8.

Non-Hodgkin lymphomas (NHL) of the B-cell type are the second most common neoplasm among patients with human immunodeficiency virus (HIV) infection and AIDS. Here, we evaluated 48 cases of AIDS-related lymphomas (ARL) diagnosed at the Histopathological Division of the Instituto de Investigaciones Hematológicas of the National Academy of Medicine. Five were females and 43 were males with a median of age of 37 years at the time of the diagnosis. Micrometer sections were prepared and stained with hematoxilin-eosin; immunohistochemical examination for the presence of Epstein-Barr virus (EBV) was carried out in 48/48 cases. Additionally, biotinilated oligonucleotides were used to determine the presence of DNA of the Human Herpes virus type-8 (HHV-8) in 14/14 biopsy smears corresponding to plasmablastic lymphomas (PL). All were fenotype B cell lymphomas with an aggressive course and advanced neoplasm disease at the time of diagnosis. Virological findings showed the strong association between EBV and AIDS-related NHL. According to the histopathological subtype, the EBV genome was detected in 16/21 (76%) diffuse large B cell lymphomas, 1/3 Burkitt lymphoma and 3/4 (75%) of primary central nervous system lymphomas. Globally, EBV genome was detected in 20/28 NHL of this series. Detection of HHV-8 was negative in all cases of PL. Hodgkin lymphoma were more frequent in males 18/20 (90%), with an aggressive clinical course and a significant predominance of the subtypes associated with worse prognosis (90% of cases). We detected a significant association between EBV and HL (90% of cases). We consider that all cases of AIDS related lymphomas should be assessed for the presence of EBV because its presence may play a role in the prognosis.

Diagnosis and treatment of congenital hemophilia with inhibitors a Latin American perspective.

The Committee of Latin America on the Therapeutics of Inhibitor Groups (CLOTTING) is composed of a number of hemophilia specialists from Latin America. The group aims to encourage the adoption of a good standard of care for Latin American patients with hemophilia. The occurrence of inhibitors in patients with hemophilia poses clinical challenges, and it is estimated that between 1000 and 3000 patients in Latin America are affected by hemophilia with inhibitors. There is an urgent need to establish a regional consensus and clinical guidelines for the diagnosis and treatment of these patients. We present an extensive review based on best current clinical practice and published literature, as seen from a Latin American perspective, taking into account the variable nature of hemophilia care available in the various countries in this Region.

Sixteen novel hemophilia A causative mutations in the first Argentinian series of severe molecular defects.

Hemophilia A (HA) is caused by heterogeneous mutations in the factor VIII gene (F8). This paper reports 16 novel small F8-mutations and rearrangements in a series of 80 Argentinian families with severe-HA. Using an updated scheme for F8-analysis, we found 37 F8-inversions (46%), 10 large deletions (13%), 13 small ins/del (16%), 7 nonsense (9%) and 8 missense mutations (10%), including 4 new ones (p.T233K, p.W1942R, p.L2297P and p.L2301S). The potential changes leading to severe-HA of these latter mutations were suggested by bioinformatics. The F8-mutation was characterised in 76 families (95%). They received genetic counselling and precise information about treatment design.

Antibodies to hepatitis C and other viral markersin multi-transfused patients from Argentina.

BACKGROUND: The knowledge of transfusion-transmitted viral infections in Argentina is scarce. A regional study organized by the Pan American Health Organization let us asses the current status. OBJECTIVES: To estimate the prevalence of HCV, HBV and HIV infection in a population of multi-transfused Argentinean patients. STUDY DESIGN: Multi-center, cross sectional study of 504 patients from national referral institutions in Buenos Aires, who had received more than ten units of blood products in more than two occasions. Demographic and clinical data were collected using a standardized questionnaire. Blood samples were analyzed for a-HCV, a-HIV, HBsAg and a-HBcore. RESULTS: Patients belonged to five diagnostic categories: onco-hematology (309; 61.3%); hemophilia (96; 19%); acute blood loss (54; 10.7% ); hemoglobinopathies (35; 6.9%); and hemodialysis (5; 1% ); five patients (1%) had two of the previous conditions. Overall prevalence rates of viral markers were: a-HCV 9.3% (CI(95%): 6.7-12.0); a-HBcore 4.8% (CI(95): 2.8-6.7); a-HIV 1.2% (CI(95%): 0.14-2.2) and HBsAg 0.20%(CI(95%): 0.2-0.59). The highest prevalence rates were found among patients living with hemophilia (PLH). There was a significant statistical association (p < 10(-5), OR =78.8 [29.7-209.7]) between a-HCV infection and having been transfused before 1993, when screening blood donors for a-HCV became mandatory in our country. The subpopulation of patients exposed to transfusion before 1993 was conformed mostly by PLH (70.9%) and hemoglobinopathies (18.6%). In this subpopulation, we found a significant association (p < 10(Dot;), OR -40 [5.68-281.66]) between years of exposure to transfusion and a-HCV among the patients under the median age (21.95 years old); however, there was no association for those above the median age (p=0.111). CONCLUSION: a-HCV was found to be the most prevalent infection in the multi-transfused patient population under study. Most infected individuals were PLH, transfused before 1993. This study will provide support for further research aimed at improving blood safety in Argentina.

Decreased recovery of replication-competent HIV-1 from peripheral blood mononuclear cell-derived monocyte/macrophages of HIV-positive patients after 3 years on highly active antiretroviral therapy.

We studied the release of p24 antigen from peripheral blood mononuclear cell-derived monocyte/macrophages obtained from 13 HIV-positive patients receiving highly active antiretroviral therapy (HAART). Although HIV-infected monocyte/macrophages were detected in 80% of patients after 36 months of continuous treatment, additional exposure to HAART reduced the chance of detecting HIV-releasing monocyte/macrophages. Therefore, after more than 3 years of HAART, recently infected monocytes may play a less important role as a source of emerging HIV-1 upon HAART interruption.

[Prevalence of hepatitis G virus infection in a cohort of hemophilic HIV positive patients]. / Prevalencia de infección por virus de hepatitis G en una cohorte de pacientes hemofílicos HIV+.

We analysed the prevalence of hepatitis G virus (HGV) infection in HCV+/HIV+ hemophilic patients determining HGV viremia in plasma by polymerase chain reaction (PCR). The overall prevalence of HGV infection was 13.51%. Viremia by HGV was more frequent in younger patients. Two subgroups of patients were considered taking into account prognosis of HIV disease progression. The prevalence of HGV infection was significantly higher in those with better prognosis and low risk of evolution to AIDS. The results suggest that HGV infection may slow disease progression, directly or indirectly.

[Avascular osteonecrosis of femoral head and neck in an AIDS patient]. / Necrosis avascular de cabeza y cuello de fémur en un paciente con sida.

Avascular osteonecrosis (AON) has increased in the last few years in patients infected with the human immunodeficiency virus type-1 (HIV-1). The most commonly affected bone is the femoral head and neck. Frequently these bilateral and clinical findings include moderate to severe pain and functional impotence of the affected joints. The etiology is multifactorial and highly active antiretroviral therapy (HAART) with protease inhibitors (PI) is probably related to its development. In the evolution, a total hip replacement may be needed. We present an hemophilic patient with AIDS, who developed a bilateral AON of the femoral head and neck during HAART.

[Splenic artery embolization for the treatment of hypersplenism in hemophilic, HIV-1 and HCV seropositive patients]. / Embolización de la arteria esplénica como tratamiento del hiperesplenismo en pacientes hemofílicos, HIV-1 y HCV seropositivos.

Thrombocytopenia is an important and common hematological abnormality in patients with HIV-1/HCV coinfection. Splenomegaly is a frequent finding in these patients and usually causes hypersplenism and thrombocytopenia. We analyzed the clinical results of a minimal invasive treatment (splenic artery embolization) for thrombocytopenia secondary to hypersplenism and refractory to other therapies in two hemophiliac patients, HIV seropositive and with cirrhosis due to chronic HCV infection. The results suggest that splenic artery embolization is a safe, relatively atraumatic and effective method for the treatment of splenomegaly and hypersplenism in selected patients with HIV-1/HCV coinfection.

Assessment of the F9 genotype-specific FIX inhibitor risks and characterisation of 10 novel severe F9 defects in the first molecular series of Argentinian patients with haemophilia B.

In haemophilia B (HB) (factor IX [FIX] deficiency), F9 genotype largely determines clinical phenotype. Aimed to characterise Argentinian families with HB, this study presents F9 genotype frequencies and their specific FIX inhibitor risk and 10 novel F9 mutations. Ninety-one DNA samples from HB patients and relatives were subjected to a new scheme: a primary screen for large deletions, a secondary screen for point mutations using conformation sensitive gel electrophoresis, DNA-sequencing and bioinformatic analysis. Our unbiased HB population (N=52) (77% with severe, 11.5% moderate and 11.5% mild HB) showed 32 missense (61.5%), including three novel mutations predicting specific structural/functional defects in silico , seven nonsense (13.5%) (one novel), five large deletions, four splice including three novel mutations affecting predicted splicing scores, three indels (two novel) and one Leiden mutation. Our comprehensive HB population included five patients with long-lasting FIX inhibitors: three nonsense (p.E35* (novel), p.R75*, p.W240*) and two entire- F9 deletions. Another patient with an indel (p.A26Rfs*14) developed transient inhibitors. A case-control analysis, based on our global prevalence of 3.05% for developing inhibitors in HB revealed that missense mutations were associated with a low risk odds ratio (OR) of 0.05 and a prevalence of 0.39%, whereas nonsense and entire- F9 deletions had significantly higher risks (OR 11.0 and 32.7) and prevalence (14.3% and 44.5%, respectively). Our cost-effective practical approach enabled identification of the causative mutation in all 55 Argentine families with HB, analysis of the molecular pathology of novel F9 defects and determination of mutation-associated FIX inhibitor risks.

Hemophilia treatment in developing countries: products and protocols.

The most important aspect of management of hemophilia is to provide adequate replacement of safe clotting factor concentrates to prevent or treat bleeding episodes. There has been considerable progress in many countries in the developing world with regard to this aspect of care. However, very little data are available in the literature on the types of products being used for factor replacement and the doses being administered for control or treatment of bleeding in different countries. These data are important to document because only then can data from different centers be compared. This article provides data from seven countries: Korea, Malaysia, Thailand, Venezuela, Argentina, Iran, and India. It shows that there is wide variability not only in the types of products used (plasma to recombinant factor concentrates) but also in the doses administered (minimal to very high) for similar indications. Prospective documentation of data on musculoskeletal outcome at these centers and correlation with dose of factor replacement could help identify different models of care. Comparing such data and collating the experience in different countries could be useful for optimizing care and establishing cost-effective models. The combined experience in the developing world in providing hemophilia services should be used to define standards of care that are practical and to set achievable goals.

Anticuerpos anti-FVIII: su evaluación por citometría de flujo / Anti FVIII antibodies: evaluation by flow cytometry

En este trabajo se describe un sistema para evaluar y caracterizar los anticuerpos anti-FVIII en pacientes con Hemofilia A Severa (HAS) que reciben el Factor como tratamiento de sustitución. Consiste en el empleo combinado de microesferas y Citometria de Flujo (CF). El rFVIII fue acoplado a microesferas de 2 µm de diámetro (m-FVIII) las cuales se incubaron con diluciones de plasma o suero de pacientes con (n=13) o sin (n=17) inhibidor, pacientes en Tratamiento Inmunotolerante (TIT)(n=5) y dadores normales (N) (n=12). Los anticuerpos se revelaron con anti-lgG humana, anti-lgG1, anti-lgG2, anti-IgG3 o anti-lgG4 biotiniladas, seguido por streptavidina-ficoeritrina. Se registraron los valores de Intensidad de Fluorescencia Media (IFM). Microesferas sin FVIII (m-Control) se utilizaron como control. El resultado se expresó como índice: (IFM de m-FVIII/IFM de m-Control) multiplicado por la inversa de la dilución de máxima respuesta. Se determinó el porcentaje de contribución de cada subclase de IgG. Los resultados presentaron un 86 por ciento de concordancia con la prueba de Bethesda y un 80 por ciento con ELISA. El método fue útil para el seguimiento de los pacientes durante el TIT. La IgG4 prevaleció en pacientes con alto título y al comienzo del TIT. La CF es fácil y rápida y requiere sólo 200 µl de muestra.

In this study, a Flow Cytometry (FC) system is described for detecting and characterizing antibodies (inhibitors) to Factor VIII (FVIII) in Severe Haemophilia A (SHA) patients following FVIII infusion. A combination of microspheres and Flow Cytometry (FC) was employed. First, rFVIII was coupled to microspheres of 2 µm of diameter (m-FVIII). Then, they were reacted with dilutions of plasma or serum of patients with (n=13) or without (n=17) inhibitors. Five patients receiving Immunotolerant Treatment (ITI) and 12 normal donors were included. Microspheres without rFVIII were used as control (m-Control). Captured anti-FVIII antibodies were detected using biotinylated anti-Human IgG, IgG1, IgG2, IgG3 or IgG4 followed by streptavidin-phycoerythrin. FC analysis was performed recording Mean Fluorescence Intensity (MFI). Results were given as an Index: the highest MFI ratio between m-FVIII and m-Control multiplied by the inverse of the corresponding plasma dilution. The contribution of each IgG subclass was expressed as percentage. FC results had 86 per cent and 80 per cent of coincidence with the Bethesda method and ELISA respectively. The test was useful to measure anti-FVIII antibodies during the ITI. IgG4 was the prevalent IgG subclass in patients with high level of inhibitors and previously to ITI. FC was easy, fast and requires only 200 µl of sample.

Linfomas asociados con la infección por el virus de la inmunodeficiencia humana: subtipos histológicos y asociación con los virus de Epstein Barr y Herpes-8 / AIDS related lymphomas: Histopathological subtypes and association with Epstein Barr virus and Human Herpes virus type-8

Los linfomas no Hodgkin (LNH) constituyen la segunda neoplasia definitoria de Sida más frecuente. En el presente trabajo se evaluaron 48 casos de linfomas asociados con la enfermedad debida al virus de la inmunodeficiencia humana (HIV) diagnosticados en la División Histopatología del Instituto de Investigaciones Hematológicas de la Academia Nacional de Medicina. Se incluyeron en la investigación 5 mujeres y 43 hombres con una mediana de edad al momento del diagnóstico de la neoplasia de 37 años. La evaluación morfológica se realizó en cortes coloreados con hematoxilina-eosina, estudio inmunohistoquímico para la detección del virus de Epstein Barr (VEB) en 48/48 casos, y mediante sonda oligonucleotídica biotinilada para la detección del ADN del Herpes virus humano tipo-8 (HHV-8) en 14/14 linfomas plasmoblásticos (LP). Todos fueron linfomas de fenotipo B, con un curso clínico agresivo y enfermedad neoplásica avanzada al momento del diagnóstico. Se pudo demostrar la fuerte asociación del VEB con los linfomas asociados al sida, con frecuencias que variaron según el subtipo histológico: 16/21 (76%) para los linfomas difusos de grandes células; 1/3 casos (33%) de linfomas de Burkitt y 3/4 (75%) en los linfomas primarios del sistema nervioso central. Globalmente, el genoma del VEB se detectó en 20/28 (71%) de las muestras de biopsias de LNH de esta serie. La detección del HHV-8 resultó negativa en los 14 LP. Los linfomas de Hodgkin fueron más frecuentes en varones,18/20 (90%), con un curso clínico agresivo y franco predominio de los subtipos histológicos de peor pronóstico (90% de casos). En estas neoplasias también se comprobó una frecuente asociación patogénica con el VEB (90% de casos).

Non-Hodgkin lymphomas (NHL) of the B-cell type are the second most common neoplasm among patients with human immunodeficiency virus (HIV) infection and AIDS. Here, we evaluated 48 cases of AIDS-related lymphomas (ARL) diagnosed at the Histopathological Division of the Instituto de Investigaciones Hematológicas of the National Academy of Medicine. Five were females and 43 were males with a median of age of 37 years at the time of the diagnosis. Micrometer sections were prepared and stained with hematoxilin-eosin; immunohistochemical examination for the presence of Epstein-Barr virus (EBV) was carried out in 48/48 cases. Additionally, biotinilated oligonucleotides were used to determine the presence of DNA of the Human Herpes virus type-8 (HHV-8) in 14/14 biopsy smears corresponding to plasmablastic lymphomas (PL). All were fenotype B cell lymphomas with an aggressive course and advanced neoplasm disease at the time of diagnosis. Virological findings showed the strong association between EBV and AIDS-related NHL. According to the histopathological subtype, the EBV genome was detected in 16/21 (76%) diffuse large B cell lymphomas, 1/3 Burkitt lymphoma and 3/4 (75%) of primary central nervous system lymphomas. Globally, EBV genome was detected in 20/28 NHL of this series. Detection of HHV-8 was negative in all cases of PL. Hodgkin lymphoma were more frequent in males 18/20 (90%), with an aggressive clinical course and a significant predominance of the subtypes associated with worse prognosis (90% of cases). We detected a significant association between EBV and HL (90% of cases). We consider that all cases of AIDS related lymphomas should be assessed for the presence of EBV because its presence may play a role in the prognosis.

A chromogenic substrate method for detecting and titrating anti-factor VIII antibodies in the presence of lupus anticoagulant.

BACKGROUND AND OBJECTIVES: The development of neutralizing anti-factor VIII antibodies (a-fVIII) is a major clinical complication. Lupus anticoagulant (LA) might affect detection of a-fVIII, since both inhibitors may act on the same coagulation pathway. Our aim was to accomplish unequivocal detection and titration of a-fVIII even in the presence of LA. DESIGN AND METHODS: We evaluated a-fVIII activity by a chromogenic substrate (CS) method in samples with a-fVIII (n=6), LA (n=12) and presumably both LA+a-fVIII (n=5). The inhibition index before (Ii) and after incubation at 37 C (Ii(37)) was estimated. We also performed factor VIII assays (one-stage and CS) and titration methods (Bethesda and CS) in parallel. RESULTS: Inhibition in the a-fVIII group (Ii=5-3200) was potentiated by incubation (Ii(37)=27-5200) as it was in LA+a-fVIII (Ii=9-21; Ii(37)=50-903). LA samples showed no or meaningless inhibitory effect (Ii=0-7; Ii(37)=0-4) or a-fVIII activity (0.00-0.06 CSU/ml) by the CS method; on the contrary, very low to moderate (0.52-7.00 BU/ml) a-fVIII activity was recorded by the Bethesda method. The two titration methods did not correlate (p>0.100) in the presence of LA, or LA+a-fVIII. Differences between factor VIII:C and factor VIIIcs were significant only in LA samples (p=0.005); however, patients with residual factor VIII activity from the LA+a-fVIII group also showed higher factor VIIIcs values than factor VIII:C ones. INTERPRETATION AND CONCLUSIONS: Results indicate the possibility of detecting and titrating a-fVIII without interference of LA by the CS method. This marks a difference with respect to the Bethesda method, in which a measurable effect can be expected in the presence of a strong LA.

Structural aberrations of chromosomes 17 and 12 in chronic B-cell disorders.

OBJECTIVES: Genomic aberrations can now be identified in approximately 80% of chronic lymphocytic leukemia, small lymphocytic lymphoma (CLL/SLL) patients. In the present study, four new structural changes involving chromosomes 17 and 12 in CLL/SLL patients are described. METHODS: Five patients were selected for inclusion in the present report among a total of 92 cases with diagnosis of CLL/SLL. Cytogenetic studies and fluorescence in situ hybridization (FISH) analysis to detect some of the most frequent cryptic aberrations occurring in CLL/SLL patients were performed. Clinical studies are also described. RESULTS: Four cases showed structural rearrangements of chromosome 17. A psu dic(17;2)(p11.2;p21), leading to p53 deletion, was observed in a patient who developed a mixed cellularity Hodgkin's disease coexisting with the CLL/SLL in the same lymph node. Epstein Barr virus was detected in the Reed-Sternberg cells. Two cases had a balanced translocation t(2;17)(p21;q23). Both patients showed trisomy 12 and clonal evolution and one of them also had 11q deletion. In addition, a der(17)t(12;17)(q13;q25) as a part of a complex karyotype, and a complex translocation t(5;12;19) (q15;p11;q13) were also found. Four patients had an adverse clinical outcome and died because of disease progression. CONCLUSIONS: Four unreported nonrandom chromosome aberrations in CLL/SLL patients, one of them who might represent a new recurrent abnormality, are described. These uncommon abnormalities, mostly associated with evolving disease, may have implications for the understanding of genetic events associated with disease progression in this pathology.

Diagnosis and treatment of congenital hemophilia with inhibitors: A Latin American perspective / Diagnóstico y tratamiento de la hemofilia congénita con inhibidores: Una perspectiva latinomericana

The Committee of Latin America on the Therapeutics of Inhibitor Groups (CLOTTING) is composed of a number of hemophilia specialists from Latin America. The group aims to encourage the adoption of a good standard of care for Latin American patients with hemophilia. The occurrence of inhibitors in patients with hemophilia poses clinical challenges, and it is estimated that between 1000 and 3 000 patients in Latin America are affected by hemophilia with inhibitors. There is an urgent need to establish a regional consensus and clinical guidelines for the diagnosis and treatment of these patients. We present an extensive review based on best current clinical practice and published literature, as seen from a Latin American perspective, taking into account the variable nature of hemophilia care available in the various countries in this Region.

El Comité Latinoamericano sobre la Terapéutica de Personas con Inhibidores (CLOTTING) está compuesto por un grupo de especialistas en hemofilia de Latinoamérica. El objetivo del grupo es promover la adopción de un estándar de tratamiento óptimo para los pacientes con hemofilia en Latinoamérica. La prevalencia de inhibidores en pacientes con hemofilia en Latinoamérica determina desafíos clínicos y se estima que de 1000 a 3000 pacientes en esta región están afectados con hemofilia e inhibidores. Existe una necesidad urgente de establecer un consenso regional y guías clínicas para el diagnóstico y tratamiento de estos pacientes. Nosotros presentamos una revisión exhaustiva basada en las mejores prácticas clínicas vigentes y en los datos publicados en la literatura, con una perspectiva latinoamericana, tomando en cuenta la variabilidad existente de los tratamientos de la hemofilia disponibles en los diferentes países de esta Región.

Genética de la hemofilia humana. Diagnóstico molecular de defectos en los genes de los factores VIII y IX de coagulación / Genetics of human haemophilia. Molecular diagnosis of defects affecting coagulation factors VIII and IX

La hemofilia A (HA) y B (HB) son enfermedades hemorrágicas hereditarias ligadas al sexo causadas por defectos de los factores VIII y IX, respectivamente. Excepto grandes inversiones recurrentes involucradas en la mitad de las HA severas, el resto de las hemofilias son causadas por distintos tipos de mutaciones grandes y pequeñas. Fueron estudiadas 70 familias con HA severa (se), 6 con seHB, 1 con HA moderada-leve (m) y 2 con mHB. Primero, en seHA, se estudio la inversión del intrón 22 (Inv22) usando un nuevo abordaje basado en PCR inversa. En los casos negativos para las inversiones se estudiaron primariamente las grandes deleciones y secundariamente las mutaciones pequeñas. En familias con HA, encontramos la Inv22 en 43 por ciento de las seHAs, una única inversión del intrón 1, 10 grandes deleciones (catorce por ciento)y 23 mutaciones pequeñas (incluyendo 10 deleciones, 3 inserciones, 4 cambios nonsense, 5 missense y 1 de splicing); y en HB, 1 deleción afectando un sitio de splicing, 4 missense y 3 nonsense. Este esquema de caracterización de mutaciones permite un estudio y análisis molecular preciso de HA y HB y beneficiará tanto al asesoramiento genético como a la provisión de información clave para el diseño del tratamiento.

Actividad citotóxica "Natural Killer" en pacientes con hemofilia / Natural Killer cytotoxic activity in hemophilic patients

This work attempats to clarify the mechanisms to functional impairment of natural killer activity in individuals with acquired immune deficiency syndrome (AIDS) and those at high risk of developing AIDS (R-AIDS). We examined the effect pf lymphokine rich supernatants (SN) on effector cells from these individuals. Mononuclear cells (CM) from R-AIDS were more susceptible to stimulation with these SN. When we studied the role of different T lymphocytes subsets in the regulation of NK activity, the results indicate that the effect of SN was the combination of opposite effects. We also studied the ability of CM from patients with Hemophilia (He) to incresase NK cytotoxicity upon stimulation with physiological and non physiological agents (IL-2,IFNa and y, Poly I:Cor PMA). The response was impaired in HIV+, especially in HIV+ with symptoms. Our results also demonstrate that NK cells with slight lytic activity (Leu7 + CD16 -) predominated in HIV+. On the other hand, the ocurrence of IL-2 receptor positive cells was similarly high in both HIV+and HIV- individuals compared to N controls. Analysis of NK activity in several individuals studied after a 2-year period revealed that this function was deteriorated with disease progression. The effect of positive or negative sera for the HIV from. He on normal NK activity was analyzed. We showd that sera from He interfered with normal NK activity. The inhibitory effect found, was higher in HIV+ sera and increased as HIV disease progressed. When the same concentration of DEAE-purified IgG was used, we found that HIV+ AIDS IgG was more inhibitory than the others

Apoptosis linfocitaria y evolución clínica en pacientes con hemofilia hiv positivos / Apoptossis and clinical evolution in HIV positive hemophilic patients

Se han postulado diversas hipótesis para explicar los defectos cuali y cuantitativos de los linfocitos T CD4+, en los pacientes HIV+. Ultimamente se ha sugerido que la apoptosis podría estar involucrada en la depleción linfocitaria observada, ya sea por acción del virus o por acción secundaria a la estimulación antigénica. El objetivo de nuestro trabajo fue determinar el IA en HeHIV+ sintomáticos. Se estudiaron 32 HeHIV+ agrupados según la clasificación del CDC en HI, IVA y IVCI. Se evaluaron morfológicamente los linfocitos periféricos en cultivos de 48 horas estimulados o no con anti-CD3. La apoptosis se valoró por medio de coloración, con naranja acridina y bromuro fr etidio. En todos los grupos de HeHIV+ el IA se encontraba muy elevado en los cultivos sin estimular, con respecto a los normales (p<0,001); tambiéen eran significativamente mayor en los HeHIV+ del grupo CDC IVCI con respecto al grupo CDC HI. Por los resultados obtenidos se comprobaría que en los HeHIV+ sintomáticos la estimulacín in vitro produce apoptosis en un porcentaje elevado de los linfocitos circulantes. El IA sería de utilidad en el seguimiento de los pacientes por su relación con el cuadro clínico

Inhibidor neutralizante e inhibidor lúpico en hemofilia: un nuevo problema diagnóstico / Anti-factor VIII inhibitors and lupus anticoagulants in hemophilia: a diagnostic problem

Los hemofílicos pueden desarrollar inhibidores neutralizantes (a-ŸVIII) y/o inhibidores lúpicos (IL). Durante 1993-1994, evaluamos 170 hemofílicos. Aquellos cuyo tiempo de tromboplastina parcial activado (TTPA) no corregía con plasma normal fueron reestudiados. En 43 pacientes (25 por ciento) se confirmó el inhibidor, realizándose a continuación: TTPA de la mezcla (1:1) luego de 1 h de incubación a 37§C; prueba con veneno de víbora Russell diluido (dRVVT), corrección (1:1) con normal y neutralización con plaquetas. El IL fue asignado en base a los resultados del dRVVT y el a-ŸVIII al detectarse efecto neutralizante contra ŸVIII e IL negativo. Siete (16 por ciento) pacientes presentaron a-ŸVIII e IL (-) (A). Los 36 (84 por ciento) restantes fueron IL (+); el efecto inhibitorio potenció con la incubación en 12 (B), fue leve en 6 (C) y negativo en 18 (D). Los antecedentes de a-ŸVIII fueron positivos en A:6/6, B:9/11, C:1/6 y D:9/17. La prevalencia de a-ŸVIII fue bajo (4 por ciento) y alto (50 por ciento) el porcentaje de IL tiempo dependiente. Estos resultados sugieren la coexistencia de a-ŸVIII con IL, o su desaparición. Se hace pues necesario el desarrollo de pruebas específicas que permitan identificar a-ŸVIII en presencia de IL.