Una inusual causa de estrechez de la vía aérea laringotraqueal / An unusual cause of laryngotracheal airway narrowing

La enfermedad relacionada con inmunoglobulina (Ig) G4 es una enfermedad de reciente conocimiento que puede comprometer cualquier órgano teniendo preferencias por ciertas regiones del cuerpo, donde la región de cabeza y cuello es uno de sus principales puntos afectados, pudiendo comprometer tanto la órbita, glándulas salivales, glándulas lagrimales, glándula tiroides, cavidades paranasales, hueso temporal, faringe y laringe. Este último órgano es infrecuentemente comprometido, solo existiendo 12 casos registrados en la literatura antes de la publicación de este escrito. Presentamos un caso de una mujer de 49 años con historia de disnea frente a esfuerzo, diagnosticándose una estenosis subglótica la cual fue manejada quirúrgicamente con una reconstrucción laringotraqueal. En el estudio histopatológico se evidenció histología compatible con enfermedad relacionada con IgG4, por lo que se inició tratamiento médico con corticotera- pia oral por un lapso de 2 meses en conjunto con inmunología. Paciente luego de 4 años de seguimiento, no ha presentado recaídas, manteniendo un lumen subglótico adecuado.

Immunoglobulin (Ig) G4-related disease is a medical condition of recent knowledge that can compromise any organ, having preferences for certain regions of the body, where the head and neck region is one of the main affected points, being able to affect orbit, salivary glands, lacrimal glands, thyroid gland, paranasal cavities, temporal bone, pharynx and larynx. The latter is infrequently compromised, with only 12 cases registered in the literature before the publication of this writing. We present a case of a 49-year-old woman with a history of exertional dyspnea, diagnosed with a sub- glottic stenosis which was managed surgically with laryngotracheal reconstruction. The histopathological study revealed histology compatible with IgG4-related disease, so medical treatment with oral corticosteroid therapy was started for a period of 2 months in conjunction with immunology. After 4 years of follow-up, the patient has not presented relapses, maintaining an adequate subglottic lumen.

Leukocyte and platelet rich fibrin in the management of medication-related osteonecrosis of the jaw: A systematic review and meta-analysis.

BACKGROUND: Osteonecrosis of the jaw (ONJ) has a frequent adverse effect after the administration of nitrogenous bisphosphonates, as non-nitrogenous bisphosphonates are metabolized more rapidly and would produce this effect to a lesser extent. The objective of this study is to analyze the results obtained in the literature with the use of L-PRF in the treatment of ONJ through a systematic review and meta-analysis. MATERIAL AND METHODS: Medline (via PubMed), Cochrane, Web of Science and Grey Literature Database was screened from which 10 were selected. RESULTS: In the meta-analysis with full resolution, combining the use of L-PRF in the treatment of ONJ, a weighted proportion (PP) of 94.3% of complete resolution is obtained (95% CI: 91.2-97.4, p<0.001), with a low degree of heterogeneity, statistically significant (I2 = 29.02%; p<0.001). When analyzing the non-resolution data, a weighted proportion (PP) of 7.7% (95% CI: 3.6-11.9; p<0.001) was obtained with moderate heterogeneity (I2: 41.87%; p=0.112). In the meta-regression, no significant correlation was found between complete resolution and year of publication (intercept = 2.88, p=0.829). In consistency analysis no major changes in PP are identified when any of the studies are eliminated, demonstrating a high reliability in the combined results. CONCLUSION: L-PRF alone or in combination with other therapies in treatment of ONJ achieved high percentages of complete lesion resolution (94.3%). In studies where L-PRF is combined with other therapies, and where the effectiveness of the other therapy alone is analyzed, L-PRF has been shown higher percentages of resolution.

Expresión de ciclo-oxigenasa 2 en carcinoma de laringe / Cyclooxigenase-2 expression in laryngeal carcinoma

Introducción: La sobrevida de carcinoma escamoso de laringe no ha aumentado significativamente en los últimos 20 años. Ciclo-oxigenasa 2 (COX-2) es una molécula que tiene un rol en la progresión tumoral ya que estimula la proliferación y angiogénesis e inhibe apoptosis celular. Objetivo: Evaluar la expresión de COX-2 en muestras de carcinoma escamoso de laringe. Material y método: Pacientes atendidos en los hospitales Barros Luco Trudeau y San Juan de Dios entre 2008 y 2011 con diagnóstico de carcinoma escamoso de laringe sin tratamiento previo. Se recolectaron tacos de biopsia los cuales fueron estudiados mediante inmunohistoquímica para la expresión de COX-2. Protocolo aprobado por Comité de Ética de la Facultad de Medicina de la Universidad de Chile. Resultados: Se incluyeron 32 casos. En 17 de ellos se describe sobreexpresión de COX-2, lo que equivale al 53% de la muestra. No hubo correlación con edad, sexo ni hábito tabáquico. Conclusión: La sobreexpresión de COX-2 es un fenómeno frecuente en carcinoma escamoso de laringe por lo cual es una molécula interesante para considerar como candidata a terapia adyuvante.

Introduction: Survival of laryngeal squamous cell carcinoma has not improved significantly in the last 20 years. Cyclooxigenase 2 (COX-2) has a role in carcinogenesis since it induces proliferation and angiogenesis, and inhibits apoptosis. Aim: To evaluate the expression of COX-2 in samples of laryngeal carcinoma. Material and methods: Patients attending Hospital San Juan de Dios and Barros Luco-Trudeau with diagnose of laryngeal carcinoma between 2008 and 2011 were included. Formalin fixed paraffin embedded samples were collected and COX-2 expression was assayed with immunohistochemistry. The study was approved by the ethics committee of Facultad de Medicina Universidad de Chile, and all patients consented. Results: 32 cases were included. COX-2 was overexpressed in 17, that is 53%. No correlation was identified with age, sex, or smoking habit. Conclusion: COX-2 overexpression is a frequent phenomenon in laryngeal carcinoma.

E X I T (ex-utero intrapartum therapy) en linfangioma cervical fetal / EXIT procedure (ex-utero intra-partum therapy) for fetal neck lymphangioma

Se presenta un caso clínico de una embarazada primigesta de 17 años, con un feto con gran masa cervical a las 20 semanas, se diagnostica como linfangioma cervical. La evaluación prenatal concluye que existe gran riesgo de asfixia perinatal por obstrucción de la vía aérea superior, se resuelve el parto mediante procedimiento EXIT (ex-utero intrapartum therapy) a las 37 semanas. Se logra realizar intubación con larin-goscopia directa, con un tiempo de by-pass uteroplacentario de 7 minutos. Se obtiene un recién nacido de 3300 g, al segundo día se opera del tumor con buenos resultados. Se revisa el protocolo del procedimiento EXIT en sus aspectos anestésicos, obstétricos, quirúrgicos y neonatológicos. Se concluye que el EXIT debe ser planteado en todo caso en que se sospeche obstrucción de la vía aérea superior y puede ser realizado en hospitales que cuenten con equipamiento habitual y un equipo médico multidisciplinario.

We report a case of primigravida patient, 17 years old, with a fetus showing a large cervical mass at 20 weeks of gestation and was diagnosed as a cervical lymphangioma. The prenatal evaluation concludes that there exists a great risk of perinatal asphyxia due to obstruction of the upper airway and therefore it is decided to perform a cesarean section at 37 weeks of gestation, using an EXIT procedure (ex-utero intra-partum therapy). We perform intubation with a semi- rigid tube having a by-pass time utero-placental of 7 minutes, obtaining a newborn of 3300 g at birth. The newborn is operated two days after birth removing the cervical tumor with good results. We review the protocol of the EXIT procedure concerning aspects related to anesthesia, obstetrics, surgery and neonatal care. We conclude that EXIT should be considered in all cases in which obstruction of the upper airway is suspected, and can be performed in hospitals that have basic surgical facilities and a multidisciplinary team.

Diagnóstico ecográfico de hernia diafragmática congénita de morgagni: a propósito de un caso en el Hospital Militar Capital de Aviación Guillermo Hernandes Jacobsen: enero 2007 / Obstetrical ecografic of congenital diaphragmatic hernia of morgagni: a purpose of a case in the Hospital Militar Capital de Aviación Guillermo Hernándes Jacobsen: january 2007

La hernia diafragmática es un defecto congénito, una anomalía que aparece antes del nacimiento cuando el feto se está formando en el útero de la madre. Consiste en un orificio en el diafragma. Existen dos tipos de hernia diafragmática. La hernia de Bochdalek, consiste en un orificio sobre el lado izquierdo del diafragma, representa aproximadamente el 90 por ciento de todos los casos. La hernia de Morgagni, consiste, en cambio, en un orificio sobre el lado derecho del diafragma. El uso amplio de la ecografía obstétrica, ha producido un aumento del diagnóstico prenatal de hernia diafragmática. Presentamos caso ocurrido en el hospital militar, paciente femenino de 21 años de edad I gesta embarazo mal controlado, se realiza eco obstétrico en la semana 34 de gestación reportando hidrotórax bilateral, hernia diafragmática congénita derecha, que es poco común, representa el dos por ciento de la totalidad de los casos, la paciente es ingresada a las 37 semanas de gestación por RPM, se realiza cesárea segmentaría obteniéndose RN femenino, no lloro ni respiro al nacer, Rx de tórax a/p se evidencia asas intestinales, hígado en hemitorax derecho con pulmón hipoplasico y dextrocardia, en hemitorax izquierdo pulmón hipoplasico.

Colestasis gravidica: a propósito de un caso / Cholestasis gravidarum: a purpose of a case

La Colestasis Gravídica en un síndrome que habitualmente se produce en el tercer trimestre del embarazo y se resuelve en el embarazo. Se caracteriza clínicamente por la presencia de prurito, ictericia o ambos sin otra disfunción hepática importante. En el siguiente trabajo se reporta caso de paciente femenino de 24 años III gestas II para FUR: 12/8/06 quien refiere de 6 días de evolución orinas coluricas, prurito generalizado predominio de manos y tórax, exámenes para clínicos con aumento de un transaminasas, fosfatasas alcalinas, se diagnóstica colestasis gravídica, patología de baja incidencia de 1/300 y 1/2000 embarazos, se considera importante realizar una revisión académica del mismo.

Trypanosoma cruzi isoenzyme variability in Ecuador: first observation of zymodeme III genotypes in chronic chagasic patients.

We have analysed by multilocus enzyme electrophoresis (MLEE) at 21 genetic loci 10 Trypanosoma cruzi stocks isolated from chronic chagasic patients and 3 stocks isolated from Triatoma dimidiata collected in human habitats from the coastal part of Ecuador (all stocks isolated in August-December 1998). Isoenzyme profiles were compared to those of 4 laboratory-cloned stocks representing the major phylogenetic subdivisions of T. cruzi. This parasite's genetic variability in Ecuador proved to be considerable, even in this limited sample, since all main isoenzyme genotypes were recorded. Four stocks from patients were identical at all loci to the reference stock MNcl2 ('major clonet #39'; T. cruzi II) isolated in Chile. The 3 stocks isolated from T. dimidiata were closely related to the formerly described zymodeme I (T. cruzi I). Finally, 3 stocks from chronic chagasic patients (one with an asymptomatic form, 2 with a cardiac-digestive form) were closely related to the formerly described zymodeme III (presently not classified in either T. cruzi I or T. cruzi II). This is the first observation of this category of T. cruzi genotypes in chronic chagasic patients. In the past it was recorded only in acute patients, wild mammals and wild triatomine bugs. The epidemiological implications of these results are discussed.

Tumores de glándulas salivales: experiencia de 20 años / Tumors in salival glands: 20 years experience

Se presenta la experiencia en le manejo de tumores de glándulas salivales de uno de los autores. Para esto se diseño un estudio descriptivo retrospectivo, revisándose 123 fichas clínicas protocolizadas durante un período de 20 años. Se incluyeron 91 mujeres y 32 hombres, consignándose edad, glándula comprometida, motivo de consulta, tiempo de evolución, factores de riesgo, examen clínico, cirugía realizada al tumor primario, manejo del cuello, radioterapia y/o quimioterapia efectuada, histología, complicaciones, tiempo de seguimiento y sobrevida a los 3 años. Los pacientes fueron divididos en 2 grupos, según histología benigna o maligna de estos tumores. Se discuten los hallazgos epidemiológicos de la muestra y el manejo terapéutico empleado, así como los resultados postoperatorios, precoces y tradíos. En ambos grupos no se encontró evidencia de recidiva tumoral, con una sobrevida de 100 por ciento para los pacientes con tumores benignos, y de 60 por ciento, a 3 años, para aquellos con tumores malignos

Estenosis glótica posterior / Rear glottal stenosis

La mayor sobrevida de pacientes sometidos a cuidados intensivos han provocado un aumento en la incidencia de estenosis glótica posterior, secundaria a intubación prolongada. Esta patología, aunque poco frecuente, es compleja y de difícil manejo. El interés de la presente publicación es mostrar los resultados logrados en la resolución de 6 casos atendidos en el Servicio de Otorrinolaringología del Hospital San Juan de Dios. En ellos se aplicaron distintas técnicas quirúrgicas, lográndose que todos los pacientes fueran decanulados, con buena capacidad funcional y conservando una voz normal en la mayoría de los casos. De la experiencia obtenida se desprende que el manejo de esta patología debe orientarse a mejorar la función respiratoria de la manera más conservadora posible

Cáncer laríngeo-hipofaríngeo: evaluación en el Hospital San Juan de Dios / Laryngo-hypopharyngeal cancer: evaluation at the San Juan de Dios hospital

El cáncer de laringe corresponde al 1 por ciento del total de cánceres y al 25 por ciento de los cabeza y cuello y aún existen controversias en relación con su manejo. En Chile, el último estudio de sobrevida data de 1989. En nuestro estudio se plantea como objetivo evaluar el cáncer de laringe en sus formas de presentación, estudio y tratamiento realizado en el Servicio de Otorrinolaringología del Hospital San Juan de Dios, además de conocer la sobrevida actual de los pacientes. Para ello se revisaron los registros clínicos de los pacientes con estudios de etapificación completo ingresados entre 1994 a 1999. Se dividió a los pacientes según la intención o no de intento cuarativo. Del Servicio de Registro Civil e Identificación se obtuvo el listado de pacientes fallecidos al cierre del estudio calculando la sobrevida a travéz del método actuarial. Resultados: Se obtuvieron 70 pacientes, 89 por ciento de sexo masculinos con promedio de 64 años (rango 40-94). Ubicación en la laringe 78 por ciento y en hipofaringe 22 por ciento. El 74,4 por ciento en estadios avanzados (III-IV). El hábito tabáquito estuvo presente en 90 por ciento y el consumo excesivo de alcohol en 55 por ciento. En el 70 por ciento se realizó intento curativo. En ellos, el 80 por ciento correspondió a la laringe y el 58 por ciento fueron de la glotis. La histología predominante fue carcinoma espinocelular. Se realizó tratamiento a un 12 por ciento con radioterapia exclusiva; a 33 por ciento con cirugía exclusiva y a un 55 por ciento tratamiento combinado: cirugía y radioterapia. Las laringectomias totales fueron en un 73 por ciento de los pacientes. Se realizó vaciamiento ganglionar cervical en el 67 por ciento siendo bilateral en un 90 por ciento. Las complicaciones alcanzaron a un 55.1 por ciento, siendo la fístula faringocutánea en un 26 por ciento. La sobrevida general a los 2 y 5 años fue, respectivamente, de 58,8 por ciento y 56,2 por ciento y dentro de los con intento curativo de un 81,4 y 78,3 por ciento respectivamente. Discusión: Se discuten los distintos factores y problemas relacionados con su manejo. Los resultados obtenidos son similares en cuanto a factores predisponentes, histología, manejo, complicaciones, localización y sobrevida a la literatura existente en Chile y en el extranjero

Eotaxin and RANTES expression by the dermal endothelium is associated with eosinophil infiltration after ivermectin treatment of onchocerciasis.

The roles of eotaxin, RANTES, and MCP-3 expression in eosinophil recruitment to the site of parasite killing that occurs following ivermectin treatment of onchocerciasis were assessed in the skin of 13 Onchocerca volvulus-infected subjects and two noninfected controls before and after ivermectin treatment. Adverse reactions in infected subjects were associated with the appearance of eosinophils in the dermis as part of a perivascular inflammatory infiltrate. Although no expression of RANTES and eotaxin was seen in dermal vascular endothelial cells in biopsies taken before treatment (nor at any time in the skin of uninfected controls), endothelial expression of both eotaxin and RANTES was noted by 24 h following treatment. While RANTES expression was transient, eotaxin expression increased in parallel with increasing eosinophil recruitment up to 60 h posttreatment. These observations indicate that endothelial expression of eotaxin and RANTES may have an important role in eosinophil recruitment into the skin during helminth-killing reactions.

Human onchocerciasis and tetanus vaccination: impact on the postvaccination antitetanus antibody response.

To investigate whether helminth infections may affect the efficacy of vaccines by impairing the immune response to nonparasite vaccine antigens, we compared the antibody responses to tetanus toxoid (TT) after tetanus vaccination in 193 subjects with Onchocerca volvulus infection with 85 comparable noninfected controls. After vaccination, the proportions of subjects in each group attaining protective levels of antitetanus antibodies were similar (96.9% infected versus 97.6% noninfected). Postvaccination increases in antitetanus immunoglobulin G (IgG) and the predominant IgG isotype, IgG1, were equivalent in both groups, as were increases in specific IgG4 and IgE; however, significantly greater increases in specific IgG2 (P < 0.05) and IgG3 (P < 0.001) were observed in the noninfected group. Stratification of the O. volvulus-infected group into two groups representing light and heavy infections revealed a significantly impaired antitetanus IgG response in those with heavy infections compared to those with light infections (P < 0.01) or no infection (P < 0.05). The impact of concurrent intestinal helminth infections on the antitetanus response was also examined; an increased IgG4/IgE ratio was seen in those infected with Strongyloides stercoralis (P < 0.05) and when all helminth infections were combined as a single group (P < 0.05). These findings indicate that concurrent infection with O. volvulus does not prevent the development of a protective antitetanus response, although heavier O. volvulus infections are able to alter the magnitude of this response, and concurrent helminth infections (O. volvulus and intestinal helminths) may alter TT-specific antibody isotype responses.

Treatment of human pulmonary paragonimiasis with triclabendazole: clinical tolerance and drug efficacy.

An open clinical trial to determine the efficacy and tolerability of postprandial doses of triclabendazole against Paragonimus mexicanus in 62 patients with pulmonary paragonimiasis from the Ecuadorian Amazon region was performed. Praziquantel was used as therapeutic control. Patients were allocated at random to the following 4 therapeutic regimens: triclabendazole, 5 mg/kg once daily for 3 d (16 patients), 10 mg/kg twice on one day (15 patients), and 10 mg/kg in a single dose (16 patients), and praziquantel, 25 mg/kg thrice daily for 3 d (15 patients). Clinical tolerance, based on the frequency and severity of adverse reactions, was superior in all 3 triclabendazole regimens to that of praziquantel. No alteration was observed in hepato-renal functions or haematological values. The clinical symptoms resolved at a comparable rate in all 4 treatment groups. A more rapid parasitological response to treatment, as determined by the reduction in the average number of parasite eggs found in sputum, was seen in patients treated with triclabendazole than with praziquantel. By day 90, 60 patients had no egg detected in their sputum; 2 patients, treated with a single dose of 10 mg/kg, had a few and were re-treated with triclabendazole (5 mg daily for 3 d). On day 365, none of the patients had eggs in their sputum. Triclabendazole can be recommended as an alternative drug of choice for the treatment of pulmonary paragonimiasis; it is as effective as praziquantel in clearing infections and better tolerated.

Impaired tetanus-specific cellular and humoral responses following tetanus vaccination in human onchocerciasis: a possible role for interleukin-10.

Onchocerca volvulus infection has been associated with impaired cellular responses to parasite antigens, an impairment that may also extend to nonparasite antigens. To investigate the mechanism of this impaired immune response, the effect of concurrent O. volvulus infection on the immune response to tetanus toxoid (TT) following tetanus vaccination was studied. The proliferative, cytokine, and antibody response to TT of O. volvulus-infected subjects (n = 19) and comparable noninfected controls (n = 20) were studied before and 6 months after vaccination with TT. Following vaccination, antibody levels, proliferative responses, and levels of interferon-gamma were significantly greater in noninfected subjects (P < .05, .001, and .05, respectively); however, infected subjects produced interleukin-10, but noninfected controls did not (P < .001). These studies indicate that concurrent infection with O. volvulus can diminish the immune response to an unrelated antigen (TT) by a mechanism that is likely to involve interleukin-10.

Comparación de dos técnicas para la determinación de glicemia por método de cinta reactiva / Comparison of 2 techniques for blood glucose measuring with reagent strips method

Dado el amplio uso de dispositivos de autocontrol para medir glucosa sanguínea con cintas reactivas, se decide comparar los resultados de mediciones de glucosa procesadas con cinta reactiva Glucostix (Bayer Diagnósticos) en un reflectómetro Glucometer GX (Miles, Elkhart, In), a partir de muestras de sangre capilar y venosa para determinar las posibles diferencias de sensibilidad en la técnica de muestreo,utilizando como referencia la glicemia en sangre total y venosa procesada en el laboratorio (Método de glucosa-oxidasa).Con este propósito se tomaron y analizaron muestras de pacientes diabéticos bajo control, 95 de sangre capilar y 11 de sangre venosa, obteniéndose un coeficiente de correlación similar en las dos muestras (0,852 y 0,7981 respectivamente), sin diferencias estadísticamente significativas entre ambos.La curva de regresión lineal demuestra que no se producen sobre o subvaloraciones importantes. El resultado comprueba una buena sensibilidad del instrumento con las muestras de sangre capilar y venosa, sin establecerse diferencias significativas en la obtención de resultados comparativos; sin embargo, el uso de estas técnicas debe realizarse con cautela, considerando las implicancias terapéuticas de sus resultados

In utero exposure to Onchocerca volvulus: relationship to subsequent infection intensity and cellular immune responsiveness.

Afro-Ecuadorian individuals from an area where Onchocerca volvulus is hyperendemic have been monitored for infection over the past 16 years. To determine whether in utero exposure to O. volvulus biases a child's subsequent immune responses, children (9 to 16 years old) for whom the mother's infection status was known were chosen for study. Children of infected mothers (n = 19) had significantly higher levels of skin microfilariae than children of uninfected mothers (n = 13; P = 0.021). While the serum levels of O. volvulus-specific immunoglobulin G (IgG), IgG subclasses, and IgE showed no significant differences between the two groups of children, peripheral blood mononuclear cells of children of infected mothers produced higher levels of Th2-type cytokines to several parasite antigens and lower levels of Th1-type cytokines to nonparasite antigens than those of children of uninfected mothers. Thus, in utero exposure to O. volvulus has a long-term effect on the child's subsequent cellular immune response that may render the child more susceptible to O. volvulus infection postnatally.

Bartonellosis in Zamora Chinchipe province in Ecuador.

Human bartonellosis was investigated in the Ecuadorian province of Zamora Chinchipe; 17 cases were identified retrospectively from hospital records over the period 1984-1995, mostly from 6 communities in the provincial district of Zumba. A questionnaire concerning risk factors for disease transmission was administered in these 6 communities. Blood samples were taken from individuals with current febrile illnesses or skin lesions suggestive of bartonellosis. Samples for detection of Bartonella bacilliformis were also taken from all school-age children in communities where historical cases had been identified by questionnaire. No bacteriologically positive case was identified and no evidence of asymptomatic infection was detected. Risk factors for disease transmission, identified by the questionnaire, included the presence of sick or dying chickens and guinea-pigs. It was suggested that bartonellosis is a zoonosis with wild animals, probably rodents, as the reservoir. The widespread use of residual insecticides and the easy availability of antibiotics is likely to have modified the epidemiology of this disease over the last decade.

Systemic cocaine challenge after chronic cocaine treatment reveals sensitization of extracellular dopamine levels in nucleus accumbens but direct cocaine perfusion into nucleus accumbens does not: implications for the neural locus of cocaine sensitization.

Rats were treated chronically with 20 mg/kg/day cocaine (by intraperitoneal injection) for 16 days, followed by 7 days of cocaine wash-out. On the next day, rats were challenged with an acute dose of cocaine administered by one of two routes (systemic or intracranial), and extra-cellular dopamine (DA) in the nucleus accumbens (Acb) was measured by in vivo microdialysis. Rats acutely challenged systemically with 20 mg/kg cocaine showed enhanced Acb extracellular DA levels (compared to control rats that had not previously received chronic cocaine). However, rats acutely challenged with intracranial cocaine by perfusion of 10(-5) M cocaine directly into the Acb did not. It is suggested that both the development and triggering of cocaine sensitization, as manifested by enhanced Acb DA content to subsequent acute cocaine challenge, may involve more than just neural mechanisms occurring locally within the Acb.

Resistance to Onchocerca volvulus: differential cellular and humoral responses to a recombinant antigen, OvMBP20/11.

Persons putatively immune (PI) to Onchocerca volvulus (Ov) infection were identified in Ecuador on the basis of epidemiologic, clinical, and parasitologic findings. Immune responses of PI subjects to a recombinant onchocercal protein, OvMBP20/11, were determined and compared with those of a comparable infected (INF) group from the same Ov-endemic area. PI subjects had significantly less antibody reactivity to this molecule; however, not all INF subjects had an antibody response. IgG1 and IgG4 were the predominant IgG subclasses induced to this molecule, and the amount of IgG1 produced was the only significant difference between the PI and INF groups. In contrast to the antibody responses, proliferative responses to OvMBP20/11 were significantly higher in PI than in INF subjects. Cytokine analysis of peripheral blood mononuclear cell culture supernatants revealed that INF subjects produced significantly more interleukin-10 in response to OvMBP20/11 than did PI subjects. This antigen induced few other cytokines, and there were no differences between study groups.

Immunity to onchocerciasis: putative immune persons produce a Th1-like response to Onchocerca volvulus.

Immunity to Onchocerca volvulus (Ov) infection is suggested by the presence of putatively immune (PI) subjects in a region of Ecuador in which Ov is endemic. PI subjects were identified by traditional diagnostic methods combined with a polymerase chain reaction-based assay for Ov DNA in skin snips. Responses of peripheral blood mononuclear cells (PBMC) from the PI group (n = 16) were compared with those of persons with active infection (microfiladermic [MF] subjects; n = 51). PBMC of PI subjects proliferated significantly more to Ov antigen (OvAg; P < .009) than did PBMC of MF persons but less to streptolysin-O (P < .001). Cytokine analysis of PBMC culture supernatants revealed that PI subjects (n = 11) produced significantly more interferon-gamma to OvAg than did those in the MF group (n = 18; P = .018), less interleukin (IL)-5 to nonparasite antigen (P = .003) and mitogen (P = .012), and less IL-10 spontaneously (P = .016). Thus, immunity to Ov may in part be mediated by an antigen-specific Th1-type response.