Near-fatal poisoning after ricin injection.

OBJECTIVE: To report a near-fatal poisoning after intentional injection of ricin from a castor bean (Ricinus communis) extract. CASE REPORT: A 21 year-old man self-injected ∼3 mL of a castor bean extract intramuscularly and subcutaneously in the left antecubital fossa. Upon admission to our ED (1 h post-exposure; day 1, D1) he was awake and alert, but complained of mild local pain and showed slight local edema and erythema. He evolved to refractory shock (∼24 h post-exposure) that required the administration of a large volume of fluids and high doses of norepinephrine and vasopressin, mainly from D2 to D4. During this period, he developed clinical and laboratory features compatible with systemic inflammatory response syndrome, multiple organ dysfunction, capillary leak syndrome, rhabdomyolysis, necrotizing fasciitis and possible compartment syndrome. The patient underwent forearm fasciotomy on D4 and there was progressive improvement of the hemodynamic status from D7 onwards. Wound management involved several debridements, broad-spectrum antibiotics and two skin grafts. Major laboratory findings within 12 days post-exposure revealed hypoalbuminemia, proteinuria, thrombocytopenia, leukocytosis and increases in cytokines (IL-6, IL-10 and TNF-α), troponin and creatine kinase. Ricin A-chain (ELISA) was detected in serum up to D3 (peak at 24 h post-exposure), with ∼79% being excreted in the urine within 64 h post-exposure. Ricinine was detected in serum and urine by LC-MS up to D5. A ricin A-chain concentration of 246 µg/mL was found in the seed extract, corresponding to the injection of ∼738 µg of ricin A-chain (∼10.5 µg/kg). The patient was discharged on D71, with limited range of motion and function of the left forearm and hand. CONCLUSION: Ricin injection resulted in a near-fatal poisoning that evolved with septic shock-like syndrome, multiple organ dysfunction and necrotizing fasciitis, all of which were successfully treated with supportive care.

Effect of ArtinM on Human Blood Cells During Infection With Paracoccidioides brasiliensis.

Infections caused by fungi are prominent in our environment and can be potentially fatal. paracoccidioidomycosis (PCM), caused by fungi of the Paracoccidioides genus, is the most frequent systemic mycosis in Brazil and the main cause of death among immunocompetent individuals. The antifungal therapy for PCM is usually effective but side effects and relapses are often reported. The latter could be avoided with alternative or complementary therapies aimed at boosting the immune response to combat this pathogen. Recent reports have pointed at the importance of an effective cellular immune response, with the participation of Th1 cells, in the resistance to and control of Paracoccidioides infection. The ArtinM lectin, extracted from jackfruit (Artocarpus heterophyllus) seeds, exhibits immunomodulatory activity against several intracellular pathogens, including Paracoccidioides brasiliensis, by promoting the development of a Th1 immune response. The aim of this work was to characterize the effect of ArtinM on peripheral blood cells of patients with PCM and on those of control individuals infected with fungal yeasts cells in vitro. Our results demonstrate that ArtinM activates human neutrophils in vitro, leading to an increase in cytokine production and CD54 expression. ArtinM activated P. brasiliensis-infected neutrophils from both healthy individuals and patients with PCM. This activation was not dependent on the dectin-1 receptor, because pre-incubation with laminarin, a dectin-1 receptor blocker, did not reverse the activated state of the cells. ArtinM also stimulated human peripheral blood mononuclear cells to secrete pro-inflammatory Th1-related cytokines, which are protective against Paracoccidioides infection. These data support the immunostimulatory action of ArtinM and encourage new studies using the lectin for the immunotherapy of PCM.

Preoperative B-type natriuretic peptide, and not the inflammation status, predicts an adverse outcome for patients undergoing heart surgery.

OBJECTIVES: B-type natriuretic peptide (BNP) and inflammatory markers are implicated in the pathophysiology of both ischemic cardiomyopathy and complications after cardiac surgery with cardiopulmonary bypass (CPB). The purpose of this study was to assess preoperative and postoperative levels of BNP, interleukin-6 (IL-6), interleukin-8 (IL-8), P-selectin, intercellular adhesion molecule (ICAM), C-reactive protein (CRP) in patients undergoing cardiac surgery with CPB and investigate their variation and ability to correlate with immediate outcome. METHODS: Plasma levels of these markers were measured preoperatively, 6 and 24 h after CBP in 62 patients. Main endpoints were requirements for intra-aortic balloon pump, intensive care unit (ICU) stay longer than five days, ventilator dependence >24 h, requirement for dobutamine, hospital stay >10 days, clinical complications (infection, myocardial infarction, renal failure, stroke and ventricular arrhythmias) and in-hospital mortality. RESULTS: Preoperative BNP levels correlate with longer ICU stay (P = 0.003), longer ventilator use (P = 0.018) and duration of dobutamine use (P < 0.001). The receiver-operating characteristic curve demonstrated BNP levels >190 pg/ml as predictor of ICU >5 days and BNP levels >20.5 pg/ml correlated with dobutamine use, with areas under the curve of 0.712 and 0.842, respectively. Preoperative levels of ICAM-1 were associated with in-hospital mortality (P = 0.042). In the postoperative period, was found association between CRP, IL-6 and P-selectin with ventilation duration (P = 0.013, P = 0.006, P < 0.001, respectively) and P-selectin with ICU stay (P = 0.009). CONCLUSIONS: BNP correlates with clinical endpoints more than inflammatory markers and can be used as a predictor of early outcome after heart surgery.

Reduced expression of systemic proinflammatory and myocardial biomarkers after off-pump versus on-pump coronary artery bypass surgery: a prospective randomized study.

BACKGROUND: The effects of off-pump (OffPCABG) and on-pump (OnPCABG) coronary artery bypass grafting (CABG) on myocardium and inflammation are unclear. OBJECTIVE: Compare the inflammatory response and myocardial injury from patients (pts) submitted to OffPCABG with those that undergo OnPCABG. METHODS: Patients with normal left ventricular function were assigned to OffPCABG (n = 40) and OnPCABG (n = 41). Blood samples were collected before and 24 hours after surgery for determination of creatine kinase (CK)-MB (CK-MB), troponin I (cTnI), interleukin (IL)-6, IL-8, P-selectin, intercellular adhesion molecule (ICAM)-1 and C-reactive protein (CRP). Mortalities were registered at 12 months. RESULTS: Preoperative CK-MB and cTnI levels were 3.1 +/- 0.6 IU and 1.2 +/- 0.5 ng/mL for OffPCABG and 3.0 +/- 0.5 IU and 1.0 +/- 0.2 ng/mL for OnPCABG pts. Postoperative CK-MB and cTnI levels were 13.9 +/- 6.5 IU and 19.0 +/- 9.0 ng/mL for OffPCABG vs 29.5 +/- 11.0 IU and 31.5 +/- 10.1 ng/mL for OnPCABG (P < .01). OffPCABG and OnPCABG pts had similar preoperative IL-6 (10 +/- 7 and 9 +/- 13 pg/mL), IL-8 (19 +/- 7 and 17 +/- 7 pg/mL), soluble P-selectin (70 +/- 21 and 76 +/- 23 pg/mL), soluble ICAM-1 (117 +/- 50 and 127 +/- 52 ng/mL), and CRP (0.09 +/- 0.05 and 0.11 +/- 0.07 mg/L). At 24 hours, for OffPCABG and OnPCABG: IL-6 was 37 +/- 38 and 42 +/- 41 g/mL; IL-8, 33 +/- 31 and 60 +/- 15 pg/mL; soluble P-selectin, 99 +/- 26 and 172 +/- 30 pg/mL; soluble ICAM-1, 227 +/- 47 and 236 +/- 87 ng/mL; and CRP, 10 +/- 11 and 14 +/- 13 mg/L (P < .01 vs preoperation; P < .01 vs OffPCABG). Increased 24-hour postoperative CRP levels was the only marker to have significant positive correlations with events and occurred just for the OnPCABG pts. In-hospital and 1-year mortalities for the OnPCABG and OffPCABG pts were 2.0% and 2.2% (P = .1) and 2.7% and 4.7% (P = .06), respectively. CONCLUSIONS: Thus, the absence of CPB during CABG preserves better the myocardium and attenuates inflammation-however, without improving survival.

Differences in the inflammatory response between patients with and those without diabetes mellitus after coronary stenting.

BACKGROUND: Patients with diabetes mellitus who undergo coronary stenting are at increased risk of restenosis. It is known that inflammation plays a crucial role in restenosis. OBJECTIVE: We assessed the inflammatory response to elective coronary stent implantation (CSI) in stable diabetic and nondiabetic patients. METHODS: C-reactive protein (CRP), soluble (s) P-selectin, and soluble intercellular adhesion molecule (sICAM)-1 plasma levels were determined in diabetic (n = 51) and nondiabetic (n = 56) patients before and 48 hours and 4 weeks after bare metal stenting (BMS). RESULTS: Diabetic patients presented significantly higher inflammatory marker levels before and after CSI. Nonetheless, diabetic and nondiabetic patients had postintervention peak of markers attained within 48 hours. At baseline, diabetic and nondiabetic patients presented CRP levels of 5.0 +/- 20.1 (P < or = 0.04) and 3.8 +/- 9.4 microg/ml and, at 48 hours postintervention, 22.0 +/- 20.2 (P = 0.001; P = 0.002) and 12.6 +/- 11.3 (P < or = 0.0001) microg/ml. Regarding sP-selectin, diabetic and nondiabetic patients obtained levels of, at baseline, 182 +/- 118 (P < or = 0.04) and 105 +/- 48 ng/ml and, at 48 hours, 455 +/- 290 (P = 0.001; P < or = 0.01) and 215 +/- 120 (P < or = 0.04) ng/ml. For diabetic and nondiabetic patients, sICAM-1 levels were, at baseline, 248 +/- 98 (P < or = 0.04) and 199 +/- 94 ng/ml and, at 48 hours, 601 +/- 201 (P = 0.001; P < or = 0.01) and 283 +/- 220 (P = 0.001) ng/ml. At 4 weeks, for all patients, markers returned to preprocedural levels: versus before PCI: *P = 0.001, (section sign)P < or = 0.0001; versus nondiabetic patients: (#)P < or = 0.04, (paragraph sign)P = 0.002, (Upsilon)P < or = 0.01. CONCLUSIONS: Diabetic and nondiabetic patients exhibited a temporal inflammatory response after an elective BMS. However, diabetic patients present higher preprocedural levels of CRP, sP-selectin, and sICAM-1 and reveal a further exacerbated inflammatory response after intervention. The differences in inflammatory response may have implications in restenosis within these two sets of patients.

Serum levels of interleukin-6 (Il-6), interleukin-18 (Il-18) and C-reactive protein (CRP) in patients with type-2 diabetes and acute coronary syndrome without ST-segment elevation.

BACKGROUND: Atherosclerosis is an inflammatory disease, and serum levels of inflammatory markers such as interleukin 6 (IL-6), interleukin 18 (IL-18) and C-reactive protein (CRP) are used to evaluate patients with coronary artery disease. In patients with type-2 diabetes, atherosclerosis is related to a larger number of events such as myocardial infarction and death, when compared with patients without diabetes. OBJECTIVE: To evaluate the inflammatory response in patients with diabetes and acute events of coronary instability. METHODS: Two groups of patients were primarily selected. The first group was comprised of diabetic outpatients with stable angina (D-CCS) and presence of coronary artery disease on coronary angiography (n=36). The second group was comprised of diabetic patients seen in the emergency room with acute coronary syndrome (D-ACS) without ST-segment elevation (n=38). Non-diabetic patients with ACS (n=22) and CCS (n=16) comprised the control group. Serum levels of CRP, IL-6 and IL-18 were determined using nephelometry (CRP) and ELISA (IL-6 and IL-18) techniques. RESULTS: Higher serum IL-6 levels were found in diabetic or non-diabetic patients with ACS than in the group with CCS. On the other hand, diabetic patients with ACS had higher CRP levels in comparison with the other groups. Serum IL-18 levels were not significantly different among the patients studied. CONCLUSION: our findings suggest a more intense inflammatory activity in patients with coronary instability. This inflammatory activity, as measured by CRP, seems to be even more intense in diabetic patients.

Níveis séricos de interleucina-6 (IL-6), interleucina-18 (IL-18) e proteína C reativa (PCR) na síndrome coronariana aguda sem supradesnivelamento do ST em pacientes com diabete tipo 2 / Serum levels of interleukin-6 (Il-6), interleukin-18 (Il-18) and C-reactive protein (CRP) in patients with type-2 diabetes and acute coronary syndrome without ST-segment elevation

FUNDAMENTO: A aterosclerose é uma doença inflamatória e níveis séricos de marcadores inflamatórios, como a interleucina 6 (IL-6), interleucina-18 (IL-18) e proteína C reativa (PCR), são utilizados para avaliação de pacientes em quadros de coronariopatia. No paciente com diabete do tipo 2, a aterosclerose está relacionada a um maior número de eventos como infarto e morte, quando comparado aos pacientes sem diabete. OBJETIVO: Avaliar a resposta inflamatória nos pacientes com diabete e eventos agudos de instabilidade coronariana. MÉTODOS: Selecionamos primariamente dois grupos de pacientes. O primeiro grupo foi composto por pacientes ambulatoriais diabéticos com angina estável (D-SCC) e presença de coronariopatia ao estudo coronariográfico (n = 36). O segundo grupo foi composto por pacientes diabéticos atendidos no pronto-socorro com quadro de síndrome coronariana aguda (D-SCA) sem supradesnivelamento do ST (n = 38). Como controle, foram utilizados pacientes sem diabete com SCA (n = 22) e SCC (n = 16). As concentrações séricas de PCR, IL-6 e IL-18 foram determinadas pelas técnicas de nefelometria (PCR) e ELISA (IL-6 e IL-18). RESULTADOS: Níveis mais elevados de IL-6 foram observados em pacientes com ou sem diabete e SCA em relação ao grupo com SCC. Por sua vez, pacientes com diabete e SCA apresentaram concentrações maiores de PCR em comparação aos outros grupos. Os níveis séricos de IL-18 não diferiram significativamente entre os pacientes estudados. CONCLUSÃO: Os resultados obtidos sugerem uma maior atividade inflamatória no paciente com quadro de instabilidade coronariana. Essa atividade inflamatória, medida pela PCR, parece ser ainda mais intensa no paciente com diabete.

BACKGROUND: Atherosclerosis is an inflammatory disease, and serum levels of inflammatory markers such as interleukin 6 (IL-6), interleukin 18 (IL-18) and C-reactive protein (CRP) are used to evaluate patients with coronary artery disease. In patients with type-2 diabetes, atherosclerosis is related to a larger number of events such as myocardial infarction and death, when compared with patients without diabetes. OBJECTIVE: To evaluate the inflammatory response in patients with diabetes and acute events of coronary instability. METHODS: Two groups of patients were primarily selected. The first group was comprised of diabetic outpatients with stable angina (D-CCS) and presence of coronary artery disease on coronary angiography (n=36). The second group was comprised of diabetic patients seen in the emergency room with acute coronary syndrome (D-ACS) without ST-segment elevation (n=38). Non-diabetic patients with ACS (n=22) and CCS (n=16) comprised the control group. Serum levels of CRP, IL-6 and IL-18 were determined using nephelometry (CRP) and ELISA (IL-6 and IL-18) techniques. RESULTS: Higher serum IL-6 levels were found in diabetic or non-diabetic patients with ACS than in the group with CCS. On the other hand, diabetic patients with ACS had higher CRP levels in comparison with the other groups. Serum IL-18 levels were not significantly different among the patients studied. CONCLUSION: our findings suggest a more intense inflammatory activity in patients with coronary instability. This inflammatory activity, as measured by CRP, seems to be even more intense in diabetic patients.

Up-regulation of NADPH oxidase components and increased production of interferon-gamma by leukocytes from sickle cell disease patients.

We have previously demonstrated that mononuclear leukocytes from patients with sickle cell disease (SCD) release higher amounts of superoxide compared with normal controls. The aim of this study was to further study the NADPH oxidase system in these patients by investigating gene expression of NADPH oxidase components, phosphorylation of p47(phox) component, and the release of cytokines related to NADPH oxidase activation in mononuclear leukocytes from patients with SCD. gp91(phox) gene expression was significantly higher in monocytes from SCD patients compared with normal controls (P=0.036). Monocytes from SCD patients showed higher levels of p47(phox) phosphorylation compared with normal controls. INF-gamma release by lymphocytes from SCD patients was significantly higher compared with normal controls, after 48 h culture with phytohemagglutinin (P=0.02). The release of TNF-alpha by monocytes from SCD patients and normal controls was similar after 24 and 48 h culture with lipopolysaccharide (P>0.05). We conclude that monocytes from SCD patients show higher levels of gp91(phox) gene expression and p47(phox) phosphorylation, along with increased IFN-gamma release by SCD lymphocytes. These findings help to explain our previous observation showing the increased respiratory burst activity of mononuclear leukocytes from SCD patients and may contribute to inflammation and tissue damage in these patients.

Pentoxifylline reduces pro-inflammatory and increases anti-inflammatory activity in patients with coronary artery disease--a randomized placebo-controlled study.

The balance between different immunological stimuli is essential in the progression and stabilization of atherosclerotic plaques. Immune regulation has been suggested as potential target for the treatment of atherosclerotic disease. We sought to determine whether treatment with pentoxifylline, a phosphodiesterase inhibitor with immunomodulating properties, could reduce the pro-inflammatory response observed in patients with acute coronary syndromes (ACS) and increase anti-inflammatory activity. In a double-blind, prospective, placebo-controlled study, 64 patients with ACS were randomized to receive pentoxifylline 400mg TID or placebo for 6 months. Analysis of the pro-inflammatory markers, C-reactive protein (CRP), interleukin (IL)-6, IL-12, interferon-gamma and tumor necrosis factor (TNF)-alpha and the anti-inflammatory cytokines, transforming growth factor (TGF)-beta1 and IL-10 were done at baseline, 1 and 6 months. Pentoxifylline treatment significantly reduced the adjusted levels of CRP and TNF-alpha compared to placebo after 6 months (P=0.04 and P<0.01, respectively). IL-12 increase was significantly less pronounced with pentoxifylline (P=0.04). The levels of the anti-inflammatory cytokine, IL-10, also declined significantly less in the pentoxifylline group compared to placebo (P<0.01) with a trend towards a higher increase of TGF-beta1 in the former group (P=0.16). Pentoxifylline reduces pro-inflammatory and increases anti-inflammatory response in patients with ACS and may have beneficial clinical effects on cardiovascular events.

Regression of coronary artery outward remodeling in patients with non-ST-segment acute coronary syndromes: a longitudinal study using noninvasive magnetic resonance imaging.

BACKGROUND: The association of plaques with outward arterial remodeling and acute coronary syndromes (ACS) has been mostly investigated by cross-sectional intravascular ultrasound studies. Magnetic resonance imaging (MRI) has made it possible to noninvasively assess the coronary vessels of patients with chronic coronary artery disease, but no study has been done in patients with ACS. We sought to serially investigate changes in coronary vessel walls of patients with ACS using noninvasive serial MRI. METHODS: A total of 42 segments of coronary arteries from 22 patients presenting with non-ST-segment elevation ACS were studied at baseline in the acute phase and at 6 months after stabilization and optimization of medical therapy. Patients received routine medical treatment during this period with control of risk factors. Vessel wall area, maximum wall thickness, mean wall thickness, and lumen area were analyzed longitudinally using MRI. RESULTS: Vessel wall area (38.8 +/- 20.0 vs 27.7 +/- 10.4 mm2; P = .001), maximum wall thickness (2.9 +/- 0.7 vs 2.5 +/- 0.6 mm; P < .001), and mean wall thickness (2.0 +/- 0.7 vs 1.6 +/- 0.5 mm; P < .001) were significantly reduced at 6 months compared with baseline, whereas lumen area did not show significant changes (11.5 +/- 4.8 vs 10.9 +/- 5.0 mm2; P = .52). The wall/lumen ratio was significantly reduced from 3.7 +/- 1.7 to 2.9 +/- 1.3 (P = .01), suggesting a regression of outward remodeling. CONCLUSION: Patients with ACS have increased coronary vessel wall thickness and area that can regress with stabilization and medical therapy over the period of 6 months. Magnetic resonance imaging can detect and serially follow these changes, monitoring coronary vascular remodeling from the acute to the chronic phase of the disease.

Differences in human antioxidized LDL autoantibodies in patients with stable and unstable angina.

BACKGROUND: Autoantibodies to oxidized LDL (anti-oxLDL) have been found in the serum of patients with coronary artery disease (CAD). This study was designed to compare the differences in anti-oxLDL titers and isotypes in unstable and stable angina patients and to correlate these results with known markers of active inflammation in CAD. METHODS: Thirty patients from a tertiary referral general hospital with documented CAD were studied. Anti-oxLDL IgG titers and its isotypes, high sensitivity C-reactive protein (hsCRP) and serum amyloid A (SAA) were measured. RESULTS: The anti-oxLDL IgG titer was lower (p=0.03) in the unstable angina group compared to the stable angina patients (0.084+/-0.102 OD versus 0.195+/-0.149 OD, respectively). The predominant IgG isotype in both groups was IgG2. IgG4 was significantly higher (0.270+/-0.146 OD, p=0.04) in the unstable angina group versus patients with stable angina (0.198+/-0.019 OD). There was a significant inverse correlation between anti-oxLDL and hsCRP and SAA in this sample population (R=0.37, p<0.05 and R=0.36, p<0.05, respectively). CONCLUSION: Patients with unstable angina have lower levels of anti-oxLDL IgG in the acute setting of CAD. Plaque instabilization does not seem to acutely modify the isotype subsets of anti-oxLDL IgG in these patients.

Natural antibodies in paracoccidioidomycosis

Recente atenção tem sido dada aos anticorpos naturais como componentes da imunidade natural e como parte integrante da rede idiotípica. Todavia, seu papel funcional em diferentes infecções tem, raramente, sido estudado. O objetivo deste trabalho foi investigar a presença de anticorpos naturais na paracoccidioidomicose (PCM). Em adição, analisamos os anticorpos específicos anti-P. brasiliensis e sua distribuição em subclasses a fim de adquirir mais conhecimento sobre a resposta imune humoral nesta micose. Nossos achados mostram que a resposta de anticorpos naturais não é acentuada na PCM quando comparada com outras infecções por parasitas e, é restrita a poucas especificidades, sugerindo que o P. brasiliensis estimula moderadamente as células B CD5+. O anticorpo anti-actina foi a principal especificidade encontrada na PCM. Os anticorpos especificos para P. brasiliensis, nos pacientes crônicos, eram, principalmente, da subclasse IgG1.

Increased Th1 activity in patients with coronary artery disease.

BACKGROUND: Atherosclerotic lesions are mainly composed of macrophages and T lymphocytes. Specific T helper type 1 (Th1) cytokines and interferon gamma (IFN-gamma) inducible chemokines have been shown to be present in these lesions, modulating the local immunologic response. To explore whether this increase in Th1 activity could also be detected in circulating cells indicating a systemic activation, we studied the peripheral expression of Th1 cytokines and chemokines in patients with coronary artery disease and controls. METHODS AND RESULTS: Fifty patients with coronary artery disease (25 with unstable angina and 25 with stable angina) and 10 controls were studied. Serum interleukin (IL)-12 and IFN-gamma and the expression of IFN-gamma inducible chemokines IP-10, Mig and their receptor CXCR3 in peripheral cells were analyzed. Serum IL-12 and intracellular expression of IFN-gamma were significantly elevated in patients with unstable angina. An enhanced expression of IFN-gamma chemokines IP-10, Mig and CXCR3 in patients with stable angina was also observed. CONCLUSIONS: This study demonstrates an increased systemic inflammatory activity in patients with coronary heart disease with a predominant Th1 response, particularly in patients with unstable angina, suggesting an important role played by this polarization in plaque formation and rupture.

Negative immunodiffusion test results obtained with sera of paracoccidioidomycosis patients may be related to low-avidity immunoglobulin G2 antibodies directed against carbohydrate epitopes.

Immunodiffusion (ID) is the serologic test most frequently used for the diagnosis and posttherapy follow-up of patients with paracoccidioidomycosis (PCM). The ID test is highly specific (100%), but its sensitivity is relatively low (90%), leading to false-negative results. The aim of this study was to determine the profiles of antibodies in sera from patients with proven PCM and with negative results in the ID test (IDneg) versus positive results in the ID test (IDpos). We analyzed 46 sera from patients with active PCM for total immunoglobulin G (IgG) and IgG subclass responses to Paracoccidioides brasiliensis gp43 antigen (treated or not treated with sodium metaperiodate) by enzyme-linked immunosorbent assay and immunoblotting. Immunoblotting showed that both IDneg and IDpos sera recognized predominantly the gp43 fraction of the P. brasiliensis antigen used in the ID test. IDneg sera contain low-avidity antibodies, low levels of specific IgG (total) and IgG1, and high levels of IgG2 compared with IDpos sera. The antibodies present in IDneg sera were predominantly directed against carbohydrate epitopes, since treatment with sodium metaperiodate resulted in a significant decrease in antibody reactivity. These data suggest that the lack of reactivity of sera from PCM patients in the ID test may be related to the production of low-avidity IgG2 antibodies directed against carbohydrate epitopes.

Cytokines and lymphocyte proliferation in juvenile and adult forms of paracoccidioidomycosis: comparison with infected and non-infected controls.

Cellular immune response to Paracoccidiodes brasiliensis antigens (PbAg) was evaluated in patients with the juvenile (JF) and adult (AF) forms of paracoccidioidomycosis as well as in a group of infected individuals living in the endemic area but without any clinical manifestation of the disease. The immune profile of this group of paracoccidioidomycosis-infected individuals was characterized by: 1) a positive skin test to P. brasiliensis antigen; 2) absence of specific antibodies; 3) a vigorous lymphoproliferative response to PbAg; and 4) a typical Th1 pattern of cytokines, with production of IFN-gamma and basal levels of IL-4, IL-5 and IL-10. At the opposite end of the spectrum were the JF patients whose proliferative response to PbAg was significantly impaired and whose cytokine pattern was characteristically Th2, i.e. lower IFN-gamma secretion and significantly higher levels of IL-4, IL-5 and IL-10. These profiles are compatible with forms of higher and lower resistance, respectively. Intermediate immune responses were observed in AF patients, whose specific lymphoproliferative response was lower than in the paracoccidioidomycosis-infected group but higher than in the JF patients. The secretion of IFN-gamma and IL-10 did not differ from the JF group, although IL-4 and IL-5 levels were significantly lower. Since AF patients are able to control fungal dissemination for decades, they can be considered more resistant than JF patients, who manifest the disease soon after infection.