Pharmacogenetic biomarkers for secukinumab response in psoriasis patients in real-life clinical practice.

BACKGROUND: Prediction of the response to a biological treatment in psoriasis patients would allow efficient treatment allocation. OBJECTIVE: To identify polymorphisms associated with secukinumab response in psoriasis patients in a daily practice setting. METHODS: We studied 180 SNPs in patients with moderate-to-severe plaque psoriasis recruited from 15 Spanish hospitals. Treatment effectiveness was evaluated by absolute PASI ≤3 and ≤1 at 6 and 12 months. Individuals were genotyped using a custom Taqman array. Multiple logistic regression models were generated. Sensitivity, specificity and area under the curve (AUC) were analysed. RESULTS: A total of 173 patients were studied at 6 months, (67% achieved absolute PASI ≤ 3 and 65% PASI ≤ 1) and 162 at 12 months (75% achieved absolute PASI ≤ 3 and 64% PASI ≤ 1). Multivariable analysis showed the association of different sets of SNPs with the response to secukinumab. The model of absolute PASI≤3 at 6 months showed best values of sensitivity and specificity. Four SNPs were associated with the capability of achieving absolute PASI ≤ 3 at 6 months. rs1801274 (FCGR2A), rs2431697 (miR-146a) and rs10484554 (HLCw6) were identified as risk factors for failure to achieve absolute PASI≤3, while rs1051738 (PDE4A) was protective. AUC including these genotypes, weight of patients and history of biological therapy was 0.88 (95% CI 0.83-0.94), with a sensitivity of 48.6% and specificity of 95.7% to discriminate between both phenotypes. CONCLUSION: We have identified a series of polymorphisms associated with the response to secukinumab capable of predicting the potential response/non-response to this drug in patients with plaque psoriasis.

Immune cells from patients with psoriasis are defective in inducing indoleamine 2,3-dioxygenase expression in response to inflammatory stimuli.

BACKGROUND: Indoleamine 2,3-dioxygenase (IDO) is an inducible enzyme that suppresses the immune response. The role of IDO as a negative regulator of inflammatory responses has been documented in several experimental autoimmune diseases. OBJECTIVES: To explore the regulation of IDO by immune cells in psoriasis and its relation with disease severity. METHODS: The expression and activity of IDO were assessed by reverse-transcriptase polymerase chain reaction, flow cytometry and high-performance liquid chromatography in peripheral blood of patients with moderate-to-severe plaque-type psoriasis. The ability of immune cells to express IDO in response to inflammatory stimuli was studied. The functional role of IDO expression was evaluated in a regulatory T cell (Treg) differentiation assay, using cocultures of immature monocyte-derived dendritic cells with autologous peripheral CD4+ T cells. RESULTS: Analysis of the kynurenine-to-tryptophan ratio in serum samples indicated higher IDO activity in patients with psoriasis than in healthy controls. However, correlation studies showed lower IDO activity in those patients with higher Psoriasis Area and Severity Index (PASI). Although myeloid dendritic cells from patients with psoriasis expressed higher levels of IDO than those from healthy controls, these cells did not upregulate IDO in response to a combination of tumour necrosis factor-α, interleukin (IL)-1ß and IL-6 cytokines. The defective expression of IDO correlated with PASI. Immature monocyte-derived dendritic cells from patients with psoriasis also expressed low levels of IDO and induced CD4+ Treg differentiation poorly. CONCLUSIONS: Immune cells from patients with psoriasis have a defect in upregulating IDO in response to inflammation associated with the severity of psoriasis.

Psoriasis in humans is associated with down-regulation of galectins in dendritic cells.

We have investigated the expression and role of galectin-1 and other galectins in psoriasis and in the Th1/Th17 effector and dendritic cell responses associated with this chronic inflammatory skin condition. To determine differences between psoriasis patients and healthy donors, expression of galectins was analysed by RT-PCR in skin samples and on epidermal and peripheral blood dendritic cells by immunofluorescence and flow cytometry. In the skin of healthy donors, galectin-1, -3 and -9 were expressed in a high proportion of Langerhans cells. Also, galectins were differentially expressed in peripheral blood dendritic cell subsets; galectin-1 and galectin-9 were highly expressed in peripheral myeloid dendritic cells compared with plasmacytoid dendritic cells. We found that non-lesional as well as lesional skin samples from psoriasis patients had low levels of galectin-1 at the mRNA and protein levels, in parallel with low levels of IL-10 mRNA compared with skin from healthy patients. However, only lesional skin samples expressed high levels of Th1/Th17 cytokines. The analysis of galectin-1 expression showed that this protein was down-regulated in Langerhans cells and dermal dendritic cells as well as in peripheral blood CD11c(+) DCs from psoriasis patients. Expression of galectin-1 correlated with IL-17 and IL-10 expression and with the psoriasis area and index activity. Addition of galectin-1 to co-cultures of human monocyte-derived dendritic cells with autologous T lymphocytes from psoriasis patients attenuated the Th1 response. Conversely, blockade of galectin binding increased IFNγ production and inhibited IL-10 secretion in co-cultures of monocyte-derived dendritic cells with CD4(+) T cells. Our results suggest a model in which galectin-1 down-regulation contributes to the exacerbation of the Th1/Th17 effector response in psoriasis patients.

Reduced expression of galectin-1 and galectin-9 by leucocytes in asthma patients.

Accumulating evidence shows that galectins play roles in the initiation and resolution phases of inflammatory responses by promoting anti- or proinflammatory effects. This study investigated the presence of three members of the galectin family (galectin-1, -3 and -9) in induced sputum samples of asthma patients, as well as their possible implication in the immunopathogenesis of human asthma. Levels of interleukin (IL)-5, IL-13, and galectins were determined in leucocytes isolated from induced sputum samples by reverse transcription-polymerase chain reaction (RT-PCR) immunofluorescence and flow cytometry. High levels of IL-5 and IL-13 mRNA were detected in sputum cells from asthma patients. In parallel, immunoregulatory proteins galectin-1 and galectin-9 showed a reduced expression on macrophages from sputum samples compared with cells from healthy donors. In-vitro immunoassays showed that galectin-1 and galectin-9, but not galectin-3, are able to induce the production of IL-10 by peripheral blood mononuclear cells from healthy donors. These findings indicate that macrophages from sputum samples of asthma patients express low levels of galectin-1 and galectin-9, favouring the exacerbated immune response observed in this disease.

Innate immune mechanisms in the pathogenesis of systemic lupus erythematosus (SLE).

Immune imbalance in SLE increases the susceptibility to infectious diseases. The aim of this study was to analyze several mechanisms related to non-specific immunity in this autoimmune disorder. We studied in vivo CD11b expression, phagocytosis, and chemotaxis in polymorphonuclear cells (PMN) from SLE patients. All tests were also performed under hrIL-8 stimulating conditions and analyzed by flow cytometry. Intracellular leucocyte (monocytes and PMN) enzyme activity was evaluated using specific substrates for cathepsin B and D, collagenase, and oxidative burst by flow cytoenzymology. An exaggerated in vivo CD11b expression was observed on PMN from SLE patients without noticeably in vitro effect upon hrIL-8. Similarly both, phagocytosis and chemotaxis were diminished and showed no response to hrIL-8 stimulation. The opposite was found in PMN from controls. Intracellular enzyme activity was comparable between groups as far as cathepsin B and D are concerned. A tendency of decreased oxidative-burst induction was noted in monocytes and PMN from SLE patients, whereas collagenase activity was found clearly increased in both leucocyte subpopulations. Our results may represent a deficient ability of the innate immune mechanisms for the clearance of infectious agents, immune complexes, satisfactory resolution of inflammatory processes and tissue repair in SLE.

Innate immune response mechanisms in non-insulin dependent diabetes mellitus patients assessed by flow cytoenzymology.

It is well known that infections in patients with diabetes mellitus are more severe, although there is controversy for increased susceptibility to them. Non-specific immune response mechanisms could be related to defense and/or susceptibility to pathogens. The aim of this study was to investigate the activity of several enzymes involved in the primary host defense mechanisms in non-insulin dependent diabetes mellitus (NIDDM). Twenty NIDDM females with a mean HbA(1c) level of 8.19% were included. No patient had clinical evidence of infection. As controls 20 healthy females were studied. The enzymes tested were dipeptidyl-peptidase I (DPP-I), cathepsin B and D, NADPH oxidase and superoxide dismutase (oxidative burst) and collagenase. Isolated leukocytes were incubated with the specific substrates in pyrogen free conditions. The intracellular enzyme activity was analyzed by flow cytometry. Collagenase enzymatic activity was similar in the three leukocyte subpopulations studied. Oxidative burst induction in monocytes was comparable between both groups. Enzyme activity of cathepsin B and D in all cell subsets, oxidative burst in PMN cells, and DPP-I in lymphocytes and monocytes from patients, was higher than those from healthy females (P<0.05). Overall, our findings demonstrate an enhanced functional status of several intracellular leukocyte enzymes in NIDDM. Furthermore, the increased oxidative burst induction and the consequent production of free radicals, may contribute to vascular complications. Other mechanisms - either from the non-specific or specific immune response - deserve investigation to establish if diabetic patients are more susceptible to infectious diseases.

Multidrug resistance-1 (MDR-1) in rheumatic autoimmune disorders. Part I: Increased P-glycoprotein activity in lymphocytes from rheumatoid arthritis patients might influence disease outcome.

BACKGROUND: Multidrug resistance (MDR) is characterized by overexpression of P-glycoprotein, a pump molecule that decreases intracellular drug concentrations by increasing drug efflux from cells. OBJECTIVE: To look for correlations between clinical status and P-glycoprotein activity and/or TNF-alpha mRNA levels in patients with rheumatoid arthritis. METHODS: Sixteen patients were studied. Based on response to therapy, eight were refractory and eight nonrefractory to treatment. Findings were compared to those in 24 healthy controls. Flow cytometry was used to evaluate P-glycoprotein activity in peripheral blood mononuclear cells isolated by gradient centrifugation and incubated with the P-glycoprotein substrate daunorubicin. TNF-alpha mRNA levels were determined using quantitative PCR. RESULTS: Patients with rheumatoid arthritis showed an increased number of lymphocytes with high P-glycoprotein activity (p = 0.0001) as compared to the normal controls. P-glycoprotein activity was higher in the refractory than in the non-refractory patient subgroup (p = 0.006). Also, TNF-alpha mRNA levels were markedly higher in the refractory subgroup than in the nonrefractory subgroup, and were undetectable in the normal controls. CONCLUSIONS: Enhanced P-glycoprotein activity may be closely related to an unfavorable clinical course and a poor response to treatment. Increased TNF-alpha expression and chronic exposure to various drugs, including glucocorticoids, may contribute to increase P-glycoprotein activity. Both high P-glycoprotein activity and excessive amounts of TNF-alpha seem associated with poor outcome in rheumatoid arthritis.

[Bacteraemia due to Eikenella corrodens secondary to periodontal infection in a neutropenic patient]. / Bacteriemia por Eikenella corrodens secundaria a infección periodontal en paciente neutropénico.

We present the case of a 44 year-old patient, without significant previous medical history, who presented a systemic infection due to Eikenella corrodens following a dental extraction in the context of an agranulocytosis of pharmacological origin due to carbimazole. During admission he was treated with broad-spectrum antibiotics and G-CSF 5 µg/kg/day, undergoing a favorable evolution and receiving hospital discharge on the seventh day. Invasive infections due to Eikenella corrodens that develop bacteriaemia are less than 20%, and are generally secondary to the drainage of previous abscesses and are usually isolated together with other microorganisms; while finding a monomicrobial primary bacteriaemia without the prior existence of endocarditis is exceptional. This is the first case of systemic infection due to this bacteria secondary to dental manipulation, where the state of transitory immunosuppression in which the patient found himself at that time was determinant in causing the disseminated infection.

Registro de evaluación de tratamiento de cáncer gástrico en Chile (REGATE): características clínicas básales de 523 pacientes / Registry of gastric cancer evaluation in Chile (REGATE): basal clinical features of 523 patients

Background: Gastric cancer is one of the leading causes of cancer-related deaths in Chile and worldwide. No consensus exists for therapeutic management. Aim: To assess clinical features and practice patterns of patients with newly diagnosed gastric cancer in Chile. Method: Chilean patients > 18 years old with newly diagnosed primary gastric adenocarcinoma enrolled by thirteen centers from different regions of Chile. Target sample size calculated according to gastric cancer prevalence in Chile. Data collected from two visits within a 10-month timeframe: baseline (patients and tumor features, treatment plan) and end of study (completion of initial treatment). Herein, baseline visit data is presented. Results: Between 2005 and 2008, 523 patients enrolled. Median age 61.3 years. Diagnosis by endoscopy in 98.5 percent patients. Location: body 35.8 percent, proximal 35.4 percent, and antral 23.9 percent. Most frequently used histopathological classification was WHO classification, with tubular adenocarcinoma being most frequent finding (53.1 percent). AJCC/UICC clinical staging (available in 31.1 percent of patients) was: 0 and I - 23.3 percent, II - 18.3 percent, III- 20.8 percent, IV - 37.6 percent. Therapeutic choice based mainly on clinical staging (49.9 percent) and included surgery in 440 patients (84.1 percent). Therapy planned by surgeon (54.9 percent) or multidisciplinary team (42.3 percent). Conclusions: REGATE is the largest prospective multicenter registry study performed in Chile. Basal visit data report that diagnosis is established frequently at advanced stages. Surgery is the most frequent therapeutic choice, (neo-) adjuvant therapies are only planned in one out of four patients. End of study visit data will provide the full scope of diagnosis and treatment of these patients.

Introducción: El cáncer gástrico es una de las principales causas de muerte por cáncer en Chile. No existe consenso acerca del tratamiento. Objetivos: Conocer características clínicas y patrón de tratamiento de pacientes con cáncer gástrico recién diagnosticado. Material y Método: Pacientes chilenos mayores de 18 años con diagnóstico reciente de adenocarcinoma gástrico primario, enrolados en 13 centros de diferentes regiones de Chile. Datos obtenidos en dos visitas dentro de período de 10 meses: basal (características del tumor y paciente, plan de tratamiento) y fin de estudio (tratamiento inicial completado). Se presentan datos de visita basal. Resultados: Entre 2005 y 2008, 523 pacientes enrolados. Mediana edad 61,3 años. Diagnóstico por endoscopia en 98,5 por ciento pacientes. Localización: corporal 35,8 por ciento, proximal 35,4 por ciento y antral 23,9 por ciento. Clasificación histopatológica más usada fue clasificación OMS, y tipo histopatológico más frecuente fue tubular 53,1 por ciento. Etapificación clínica AJCC/UICC (disponible en 37,6 por ciento de pacientes) distribuida en: 0 y I - 23,3 por ciento, II -18,3 por ciento, III - 20,8 por ciento, IV - 37,6 por ciento. Principal característica clínica para elección de terapia planeada fue etapificación clínica (49,9 por ciento). Plan de tratamiento consideró cirugía en 440 pacientes (84,1 por ciento). En mayoría de casos, plan terapéutico decidido por cirujano (54,9 por ciento) o equipo multidisciplinario (42,3 por ciento). Conclusiones: REGATE es el estudio de registro prospectivo multicéntrico más grande desarrollado en Chile. Datos visita basal informan que diagnóstico se establece frecuentemente en etapas avanzadas. Cirugía es alternativa terapéutica más frecuentemente indicada; terapias (neo-) adyuvantes sólo son ofrecidas a uno de cuatro pacientes. Datos visita fin de estudio proveerá visión completa del diagnóstico y tratamiento de estos pacientes.

IL-15 and IL-15R in leucocytes from patients with systemic lupus erythematosus.

OBJECTIVE: To assess the functional status of the IL-15/IL-15Ralpha cytokine system in different leucocyte subsets from patients with systemic lupus erythematosus (SLE). METHODS: Eighteen patients with SLE (10 with inactive and eight with active disease) and 14 healthy individuals were studied. Serum levels and in vitro production of IL-15 were determined. In addition, the expression of IL-15 receptor alpha (IL-15Ralpha) and membrane-bound IL-15 was assessed and the in vitro effects of IL-15 on CD69 and CD64 expression, interferon-gamma and TNF-alpha synthesis, respiratory burst induction and apoptosis were studied. RESULTS: Serum levels of IL-15 were significantly increased in inactive and active patients with SLE. Accordingly, the in vitro synthesis and release of IL-15 by monocytes in response to IFN-gamma+lipopolysaccharide was significantly enhanced in SLE patients with active disease, as was the percentage of membrane-bound IL-15+ monocytes. On the other hand, enhanced basal expression of IL-15Ralpha was detected in leucocytes from SLE patients, with defective induction upon stimulation with phytohaemagglutinin or phorbol myristate acetate/ionomycin. Furthermore, diminished induction of CD69 expression and interferon-gamma and TNF-alpha synthesis by recombinant human IL-15 was detected in peripheral blood mononuclear cells from SLE, and there was defective induction of CD64 and priming for respiratory burst in neutrophils. The anti-apoptotic effect of IL-15 was diminished in leucocytes from SLE patients. CONCLUSION: Our data indicate that there is enhanced synthesis of IL-15 by immune cells from SLE patients, with a poor response to this cytokine by different leucocyte subsets. This abnormal function of IL-15/IL-15Ralpha may contribute significantly to the pathogenesis of SLE.

[Duodenal obstruction caused by cholelithiasis (Bouverets' syndrome): a clinical case]. / Obstrucción duodenal por cálculo biliar (sindrome de Bouveret): caso clínico.

A 55 year old man presented with vomiting, abdominal pain, diarrhea, jaundice and choluria. An obstruction of the gastric outlet by a large gallstone located at the duodenum was demonstrated by radiologic, ultrasonographic and endoscopic examinations. The stone could not be removed through endoscopy and the patient was successfully operated on. A review of published reports is included.

Stimulation through CD50 preferentially induces apoptosis of TCR1+ human peripheral blood lymphocytes.

Apoptosis has an important role in several key immunological phenomena such as regulation of the immune response, and deletion of auto-reactive cells. This phenomenon is induced following the interaction of several cell membrane receptors with their respective ligands or after cell activation. We have studied the possible effect of signaling through CD50/ICAM-3 and CD69/AIM on apoptosis of peripheral blood lymphocytes. Apoptosis was assessed by both flow cytometry analysis (content of cell DNA and binding to annexin V), and detection of DNA fragmentation by agarose gel electrophoresis. We found that a stimulatory anti-CD50 mAb was able to induce a small but significant degree of apoptosis in resting peripheral blood mononuclear cells from most donors; this effect was dose-dependent and was evident as early as at 12 h, with a maximal induction at 48 h. Studies with T and non-T cells showed that only the former cell population was sensitive to the induction of apoptosis through CD50. Further experiments revealed that the anti-ICAM-3 mAb preferentially induced apoptosis of TCR gamma delta-bearing cells. In addition, we found a significant increase in Cai2+ in PBMC stimulated with an anti-CD50 mAb, suggesting the involvement of this signaling pathway in the induction of apoptosis through this adhesion receptor. In contrast, under our experimental conditions, stimulation through CD69 did not have any effect on the induction of apoptosis on either cultured T lymphoblasts or PMA-stimulated PBMC. Our findings suggest that the interaction of CD50 with its natural ligand LFA-1 results in the induction of apoptosis in a significant fraction of resting PBMC. This phenomenon may be involved in immune regulation, lymphocyte turnover and peripheral deletion of auto-reactive cells.

Therapy with statins in patients with refractory rheumatic diseases: a preliminary study.

We have explored the therapeutic potential of statins in patients with different inflammatory rheumatic diseases refractory to conventional therapy. We found that simvastatin (80mg o.d. for eight days) induced a rapid and significant reduction in proteinuria levels in three systemic lupus erythematosus (SLE) patients. A similar kind of therapy had a marked beneficial effect in a patient with Wegener's granulomatosis and a patient with erythema nodosum. On the other hand, five patients with rheumatoid arthritis (RA) who received atorvastatin for eight days (20mg/day) showed reduction in C-reactive protein levels and a clinical improvement that was classified as an ACR20 response. Prior to the administration of statins, all these patients had received aggressive conventional therapy with no satisfactory response. A significant reduction in spontaneous apoptosis of peripheral blood lymphocytes and expression of CD69 and HLA-DR was observed in SLE patients after simvastatin therapy. These results prompted us to perform a pilot short-time comparative (simvastatin versus chloroquine) open clinical trial in 15 patients with RA who were receiving methotrexate as a single disease modifying antirheumatic drug with no satisfactory response. Most patients (9/10) who received simvastatin (40mg/day) showed an ACR50 or better response after eight weeks, whereas such a response was not observed in any patient (0/5) treated with chloroquine. Our preliminary results indicate that statins may be an important therapeutic tool for the treatment of inflammatory rheumatic diseases.

[Bendazac hepatotoxicity: analysis of 16 cases]. / Hepatotoxicidad por bendazaco: análisis de 16 casos.

Hepatic lesions induced by non-steroid antiinflammatory drugs are a common cause of disease, particularly among elderly patients. Although its clinical expression is polymorphous, occasional increases in serum transaminase values predominate. Sixteen cases of liver involvement by bendazac were studied. This NSAID is used in Spain for the treatment of cataracts, from a total of 112 patients observing such therapy. The clinical spectrum of liver disease induced by bendazac is discussed and emphasis is placed on the necessity to judiciously select the indications for NSAIDs.

Presence of activated lymphocytes in the peripheral blood of patients with halo nevi.

BACKGROUND: The involution of the central pigmented lesion in halo nevus (HN) seems to be mediated by an immune response against self antigens expressed by melanocytes. OBJECTIVE: We assessed the presence of activated lymphocytes in the peripheral blood lymphocytes from patients with HN. METHODS: Peripheral blood was obtained from patients with HN associated with benign pigmented lesions (5) or melanoma (2) as well as from patients with melanoma without HN (5) and healthy subjects (10). Activated lymphocytes were detected by flow cytometry analysis using monoclonal antibodies (mAb) against CD69, CD71, CD98, HLA-DR, and activated beta(1) integrins (HUTS-21 mAb). RESULTS: The peripheral blood lymphocytes from patients with HN, associated with either benign or malignant lesions, exhibited a significantly higher expression of all activation markers studied compared with patients with melanoma without HN or compared with healthy subjects. Therefore the peripheral blood of HN patients contained a significant fraction of lymphocytes with an activated (CD69(+), HLA-DR(+), CD98(bright)), cell proliferating (CD71( bright)), and high adhesive (HUTS-21(bright)) phenotype. These activated cells disappeared from peripheral blood after the surgical resection of the skin lesion. CONCLUSION: Our findings further support the involvement of immune activation in HN phenomenon.

Penetrating anti-DNA monoclonal antibodies induce activation of human peripheral blood mononuclear cells.

Different studies have shown that some autoantibodies are able to penetrate into living cells and that this phenomenon has functional consequences, including apoptosis. We have explored the effect of anti-DNA antibodies (Ab) on the in vitro activation of peripheral blood mononuclear cells (PBMNC) and found that a human polyclonal anti-DNA, IgG, which efficiently penetrated living cells, was able to induce the expression of different cell activation antigens in vitro such as CD69, CD71 or CD98 by PBMNC from normal individuals. However, the cell activation phenotype induced by anti-DNA Ab was considered anomalous since the expression of some activation antigens was not up-regulated, and others showed aberrant behaviour (such as down-regulation of ICAM-1 expression). Similar results were obtained using different murine anti-DNA monoclonal antibodies (mAb). In addition, mAb that showed an efficient ability to penetrate living cells tended to have a greater effect on PBMNC activation. Anti-DNA Ab were also able to induce a noticeable expression of CD95/Fas. These data indicate that penetrating anti-DNA Ab are able to induce an anomalous activation state in vitro in a significant fraction of PBMNC. We believe this effect may occur in vivoand could have an important function in the pathogenesis of the immune dysregulation seen in SLE.

Effect of arsenic, cadmium and lead on the induction of apoptosis of normal human mononuclear cells.

The aim of this work was to investigate the effect of cadmium, lead and arsenic on the apoptosis of human immune cells. Peripheral blood mononuclear cells (MNC) were incubated with increasing concentrations of these metals and then cellular apoptosis was determined by flow cytometry and by DNA electrophoresis. We found that arsenic induced a significant level of apoptosis at 15 microM after 48h of incubation. Cadmium had a similar effect, but at higher concentrations (65 microM). In addition, cadmium exerted a cytotoxic effect on MNC that seemed to be independent of the induction of apoptosis. In contrast, concentrations of lead as high as 500 microM were nontoxic and did not induce a significant degree of apoptosis. Additional experiments showed that arsenic at concentrations as low as 1.0 microM had a significant pro-apoptotic effect when cells were cultured in the presence of this pollutant for more than 72. Non-T cells were more susceptible than T lymphocytes to the effect of arsenic and cadmium. Interestingly, MNC from children chronically exposed to arsenic showed a high basal rate of apoptosis and a diminished in vitro sensibility to this metalloid. Our results indicate that both arsenic and cadmium are able to induce apoptosis of lymphoid cells, and suggest that this phenomenon may contribute to their immunotoxic effect in vivo.

[Efficacy of acetazolamide treatment of patients with hypercapnia and superimposed metabolic alkalosis]. / Eficacia del tratamiento con acetazolamida en pacientes con hipercapnia y alcalosis metabólica sobreimpuesta.

BACKGROUND: Metabolic alkalosis usually complicates the evolution of patients with hypercapnia under diuretic or steroid therapy. The objective of this study was to analyze the efficiency of therapy with acetazolamide, a reversible carbonic anhydrase inhibitor, in this condition. PATIENTS AND METHODS: Prospective study conducted at our hospital from June 1994 to March 1996, with 45 patients who had chronic respiratory acidosis and metabolic alkalosis. After a previous stabilization of the patient and eventually the discontinuation of diuretic or corticosteroid drugs fro 24-48 hours, 500 or 750 mg of acetazolamide were administered daily for 48 hours. Later, variations both in arterial gasometry and venous electrolytes were analyzed by comparing two means of paired data. RESULTS: After therapy with acetazolamide a clinical improvement was observed in patients, a decrease in PaCO2, pH and CO3H (p < 0.001) and an increase in PaO2 (p < 0.001). Hypochloremia (82.2%) and hypopotassemia (33.3%) were the most common electrolytic abnormalities before therapy. Both abnormalities improved significantly after the administration of acetazolamide. In five patients (11.1%) acetazolamide was discontinued when metabolic acidosis appeared, which only in three cases was associated with acidemia. No secondary effects were observed. CONCLUSIONS: Acetazolamide is an efficient alternative for treatment of patients with respiratory acidosis and metabolic alkalosis, particularly when other more common measures in this condition (discontinuation of diuretics and/or volemic replacement) have failed or are contraindicated. On the other hand, the emergence of relevant secondary effects is unlikely.