Coeficiente de correlación intraclase intra- e interobservador de la maniobra pivot-shift mediante aplicación para móviles: «pivot-shift meter¼ / Intraclass correlation intra- and inter-observer of the pivot-shift maneuver through mobile application: «pivot-shift meter¼

Resumen: Introducción: El ligamento cruzado anterior es una estructura anatómica que tiende a dar problemas a los especialistas al formular un diagnóstico certero. Existen herramientas de medición que apoyan el diagnóstico como el KT1000; sin embargo, aún presenta algunas limitaciones, pues sólo logra medir un solo eje de movimiento, mientras que la maniobra de pivot-shift logra capturar más información sobre el estado del ligamento, ya que permite evaluar los tres ejes de movimiento de la articulación. La maniobra de pivot-shift carece de una ejecución estándar, por ello puede producir discordancia entre evaluadores; así se crea la necesidad de una herramienta capaz de estandarizar la maniobra al tiempo que arroje una medición interpretable. Material y métodos: La aplicación «pivot-shift meter¼ es un software para móviles capaz de capturar información de los movimientos realizados al ejecutar una maniobra de pivote. Se utilizó el índice de correlación intraclase para medir la correlación intra- e interobservador de la información capturada por la aplicación. Los datos fueron obtenidos de 66 participantes aleatorios, mediante el giroscopio integrado del teléfono móvil. Resultados: Con los 66 ensayos realizados se observó que los evaluadores tienden a alcanzar una alta reproducibilidad al ejecutar las maniobras dentro del periodo de tiempo establecido por la aplicación, que alcanzó un índice de correlación intraclase por encima de 90%. Conclusión: La correlación intra- e interobservador es lo suficientemente alta como para poder realizar un análisis cuantitativo de la maniobra de pivot-shift a través de un teléfono móvil.

Abstract: Introduction: The anterior cruciate ligament is an anatomical structure that tends to cause problems for specialists when formulating an accurate diagnosis. There are measurement tools that support the diagnosis such as the KT1000; however, it still has some limitations, since it only manages to measure a single axis of movement, while the «pivot-shift¼ maneuver manages to capture more information about the state of the ligament, as it allows to evaluate the three axes of movement of the joint. The «pivot-shift¼ maneuver lacks a standard execution, therefore it can produce disagreement between evaluators; this creates the need for a tool capable of standardizing the maneuver, while providing an interpretable measurement. Material and methods: Pivot-shift meter application, a mobile software capable of capturing information on the movements made when executing a pivot maneuver. Intraclass correlation coefficient to measure the intra- and inter-observer correlation of the information captured by the application. The data was obtained from 66 random participants, using the mobile phone's built-in gyroscopes. Results: With the 66 tests carried out, it was observed that the evaluators tend to achieve high reproducibility when executing the maneuvers within the time period established by the application, which reached an intraclass correlation coefficient above 90%. Conclusion: The intra- and inter-observer correlation is high enough to be able to perform a quantitative analysis of the pivot-shift maneuver, through a mobile phone.

[Quantitative classification of pivot-shift maneuver]. / Clasificación cuantitativa de la maniobra de pivot-shift.

INTRODUCTION: The diagnosis of ACL injury is established with the physical examination that includes the Lachman maneuver and the pivot-shift test since it has the highest positive predictive value. Imaging tests such as MRI are still used for confirmation of the same; so the quantification of clinical maneuvers is sought. MATERIAL AND METHODS: Prospective clinical study in which the maneuvers of pivot-shift and Lachman are quantified for later classification. RESULTS: Of 36 patients, 64% found a range between 0 and 3 mm when subtracting the value of the affected knee from the value of the healthy knee. It was found that 28% of the patients recorded values of KT-1000 ranging between 4 and 6 mm of displacement. In 8% of the total patients, values of KT-1000 were found that exceeded 7 mm of displacement. The data obtained are normalized and classified into 3 degrees of injury: grade 1 with partial injury; grade 2 with complete anteromedial and partial injury in posterolateral bundle; grade 3 with complete injury of both bundles. CONCLUSION: A classification is proposed for the degrees of ACL injury with future application to a more personalized reconstruction.

INTRODUCCIÓN: El diagnóstico de lesión del ligamento cruzado anterior se establece con la exploración física que incluya la maniobra de Lachman y la prueba de pivot-shift, ya que cuenta con el mayor valor predictivo positivo. Aún se recurre a pruebas de gabinete como la RMN para la confirmación del mismo; por lo que se busca la cuantificación de maniobras clínicas. MATERIAL Y MÉTODOS: Estudio clínico prospectivo en el que se cuantifican las maniobras de pivot-Shift y Lachman para su posterior clasificación. RESULTADOS: De 36 pacientes, 64% se encontró un rango entre 0 y 3 mm al restar al valor de la rodilla sana el valor de la rodilla afectada. Se encontró que 28% de los pacientes, registraron valores de KT-1000, que oscilan entre los 4 y 6 mm de desplazamiento. En 8% del total de los pacientes se encontraron valores de KT-1000 que superaron los 7 mm de desplazamiento. Se normalizan los datos obtenidos y se clasifican en 3 grados de lesión: grado 1 con lesión parcial; grado 2 con lesión completa de haz anteromedial y parcial en haz posterolateral; grado 3 con lesión completa de ambos haces. CONCLUSIONES: Se propone una clasificación para los grados de lesión del LCA con futura aplicación a una reconstrucción más personalizada.

Clasificación cuantitativa de la maniobra de pivot-shift / Quantitative classification of pivot-shift maneuver

Resumen: Introducción: El diagnóstico de lesión del ligamento cruzado anterior se establece con la exploración física que incluya la maniobra de Lachman y la prueba de pivot-shift, ya que cuenta con el mayor valor predictivo positivo. Aún se recurre a pruebas de gabinete como la RMN para la confirmación del mismo; por lo que se busca la cuantificación de maniobras clínicas. Material y métodos: Estudio clínico prospectivo en el que se cuantifican las maniobras de pivot-Shift y Lachman para su posterior clasificación. Resultados: De 36 pacientes, 64% se encontró un rango entre 0 y 3 mm al restar al valor de la rodilla sana el valor de la rodilla afectada. Se encontró que 28% de los pacientes, registraron valores de KT-1000, que oscilan entre los 4 y 6 mm de desplazamiento. En 8% del total de los pacientes se encontraron valores de KT-1000 que superaron los 7 mm de desplazamiento. Se normalizan los datos obtenidos y se clasifican en 3 grados de lesión: grado 1 con lesión parcial; grado 2 con lesión completa de haz anteromedial y parcial en haz posterolateral; grado 3 con lesión completa de ambos haces. Conclusiones: Se propone una clasificación para los grados de lesión del LCA con futura aplicación a una reconstrucción más personalizada.

Abstract: Introduction: The diagnosis of ACL injury is established with the physical examination that includes the Lachman maneuver and the pivot-shift test since it has the highest positive predictive value. Imaging tests such as MRI are still used for confirmation of the same; so the quantification of clinical maneuvers is sought. Material and methods: Prospective clinical study in which the maneuvers of pivot-shift and Lachman are quantified for later classification. Results: Of 36 patients, 64% found a range between 0 and 3 mm when subtracting the value of the affected knee from the value of the healthy knee. It was found that 28% of the patients recorded values of KT-1000 ranging between 4 and 6 mm of displacement. In 8% of the total patients, values of KT-1000 were found that exceeded 7 mm of displacement. The data obtained are normalized and classified into 3 degrees of injury: grade 1 with partial injury; grade 2 with complete anteromedial and partial injury in posterolateral bundle; grade 3 with complete injury of both bundles. Conclusion: A classification is proposed for the degrees of ACL injury with future application to a more personalized reconstruction.

[Intraclass correlation intra- and inter-observer of the pivot-shift maneuver through mobile application: ''pivot-shift meter'']. / Coeficiente de correlación intraclase intra- e interobservador de la maniobra pivot-shift mediante aplicación para móviles: ''pivot-shift meter''.

INTRODUCTION: The anterior cruciate ligament is an anatomical structure that tends to cause problems for specialists when formulating an accurate diagnosis. There are measurement tools that support the diagnosis such as the KT1000; however, it still has some limitations, since it only manages to measure a single axis of movement, while the "pivot-shift" maneuver manages to capture more information about the state of the ligament, as it allows to evaluate the three axes of movement of the joint. The "pivot-shift" maneuver lacks a standard execution, therefore it can produce disagreement between evaluators; this creates the need for a tool capable of standardizing the maneuver, while providing an interpretable measurement. MATERIAL AND METHODS: Pivot-shift meter application, a mobile software capable of capturing information on the movements made when executing a pivot maneuver. Intraclass correlation coefficient to measure the intra- and inter-observer correlation of the information captured by the application. The data was obtained from 66 random participants, using the mobile phone's built-in gyroscopes. RESULTS: With the 66 tests carried out, it was observed that the evaluators tend to achieve high reproducibility when executing the maneuvers within the time period established by the application, which reached an intraclass correlation coefficient above 90%. CONCLUSION: The intra- and inter-observer correlation is high enough to be able to perform a quantitative analysis of the pivot-shift maneuver, through a mobile phone.

INTRODUCCIÓN: El ligamento cruzado anterior es una estructura anatómica que tiende a dar problemas a los especialistas al formular un diagnóstico certero. Existen herramientas de medición que apoyan el diagnóstico como el KT1000; sin embargo, aún presenta algunas limitaciones, pues sólo logra medir un solo eje de movimiento, mientras que la maniobra de pivot-shift logra capturar más información sobre el estado del ligamento, ya que permite evaluar los tres ejes de movimiento de la articulación. La maniobra de pivot-shift carece de una ejecución estándar, por ello puede producir discordancia entre evaluadores; así se crea la necesidad de una herramienta capaz de estandarizar la maniobra al tiempo que arroje una medición interpretable. MATERIAL Y MÉTODOS: La aplicación "pivot-shift meter" es un software para móviles capaz de capturar información de los movimientos realizados al ejecutar una maniobra de pivote. Se utilizó el índice de correlación intraclase para medir la correlación intra- e interobservador de la información capturada por la aplicación. Los datos fueron obtenidos de 66 participantes aleatorios, mediante el giroscopio integrado del teléfono móvil. RESULTADOS: Con los 66 ensayos realizados se observó que los evaluadores tienden a alcanzar una alta reproducibilidad al ejecutar las maniobras dentro del periodo de tiempo establecido por la aplicación, que alcanzó un índice de correlación intraclase por encima de 90%. CONCLUSIÓN: La correlación intra- e interobservador es lo suficientemente alta como para poder realizar un análisis cuantitativo de la maniobra de pivot-shift a través de un teléfono móvil.

Estudio comparativo de reconstrucción de ligamento cruzado anterior entre las técnicas de Un Haz y U-Dos / Comparative study of anterior cruciate ligament reconstruction between the One Band and U-Two techniques

Resumen: Introducción: Las lesiones del LCA se encuentran dentro de las lesiones ligamentarias más frecuentes. Esto ha llevado al desarrollo de diferentes técnicas quirúrgicas para recuperar la estabilidad de la rodilla. Material y métodos: Estudio clínico, aleatorizado, ciego comparando técnicas de reconstrucción de LCA con Un Haz y «U-Dos¼ mediante escalas clínicas y artrometría con KT-1000 y Pivot Shift Meter. Resultados: De 36 pacientes, 52.94% fue sorteado para la técnica de Un Haz y 47.06% para «U-Dos¼. En 11.76% de los pacientes se presentó un desplazamiento mayor a 11 mm en la rodilla afectada con KT-1000. En 8.82% se mostró un desplazamiento anterior igual en ambas rodillas. Un paciente presentó un desplazamiento anterior mayor posterior a la cirugía de reconstrucción con la técnica de Un Haz, pero con mejoría en las escalas clínicas. En las mediciones de Pivot Shift se encontró una diferencia en el desplazamiento mayor a los 4,000 m/s en el eje de las X tras la técnica de Un Haz en comparación con la rodilla sana calculando integrales, mientras que con U-Dos la diferencia fue menor de 600 m/s. En el eje de «Y¼ se encontró una diferencia > 3,500 m/s entre la pierna sana y la lesionada, la cual disminuye a menos de 2,000 m/s tras la reconstrucción mediante técnica de U-Dos. Conclusiones: A lo largo del estudio se han encontrado diferencias en la evolución de los pacientes que indican que la reparación mediante la técnica de U-Dos tiene mejores resultados al lograr recuperar la estabilidad anteroposterior y rotacional del miembro afectado.

Abstract: Introduction: ACL injuries are found within the most common ligament injuries. This has led to the development of different surgical techniques to restore knee stability. Material y Methods: Clinical study, randomized, blind comparing ACL reconstruction techniques with One Band and «U-Two¼ using clinical scales and arthrometria with KT-1000 and Pivot Shift Meter. Results: Of 36 patients, 52.94% was drawn for the One Band technique and 47.06% for «U-Two¼. 11.76% of patients had a displacement greater than 11mm in the affected knee with KT-1000. 8.82% showed an equal anterior displacement on both knees. One patient had a major previous displacement after reconstruction surgery with the one band technique, but with improvement on clinical scales. Pivot Shift measurements found a difference in displacement greater than 4,000 m/s on the X axis following the One Band technique compared to the healthy knee calculating integrals, while with U-Two the difference was less than 600 m/s. On the Y axis a difference of > 3,500 m/s was found between the healthy and the injured leg, which decreases to less than 2,000 m/s after reconstruction using U-Two technique. Conclusions: Differences have been found throughout the study in patient evolution, indicating that repair using the U-Dos technique has better results in recovering the anteroposterior and rotational stability of the affected limb.

[Comparative study of anterior cruciate ligament reconstruction between the One Band and U-Two techniques]. / Estudio comparativo de reconstrucción de ligamento cruzado anterior entre las técnicas de Un Haz y U-Dos.

INTRODUCTION: ACL injuries are found within the most common ligament injuries. This has led to the development of different surgical techniques to restore knee stability. MATERIAL Y METHODS: Clinical study, randomized, blind comparing ACL reconstruction techniques with One Band and «U-Two¼ using clinical scales and arthrometria with KT-1000 and Pivot Shift Meter. RESULTS: Of 36 patients, 52.94% was drawn for the One Band technique and 47.06% for «U-Two¼. 11.76% of patients had a displacement greater than 11mm in the affected knee with KT-1000. 8.82% showed an equal anterior displacement on both knees. One patient had a major previous displacement after reconstruction surgery with the one band technique, but with improvement on clinical scales. Pivot Shift measurements found a difference in displacement greater than 4,000 m/s on the X axis following the One Band technique compared to the healthy knee calculating integrals, while with U-Two the difference was less than 600 m/s. On the Y axis a difference of 3,500 m/s was found between the healthy and the injured leg, which decreases to less than 2,000 m/s after reconstruction using U-Two technique. CONCLUSIONS: Differences have been found throughout the study in patient evolution, indicating that repair using the U-Dos technique has better results in recovering the anteroposterior and rotational stability of the affected limb.

INTRODUCCIÓN: Las lesiones del LCA se encuentran dentro de las lesiones ligamentarias más frecuentes. Esto ha llevado al desarrollo de diferentes técnicas quirúrgicas para recuperar la estabilidad de la rodilla. MATERIAL Y MÉTODOS: Estudio clínico, aleatorizado, ciego comparando técnicas de reconstrucción de LCA con Un Haz y «U-Dos¼ mediante escalas clínicas y artrometría con KT-1000 y Pivot Shift Meter. RESULTADOS: De 36 pacientes, 52.94% fue sorteado para la técnica de Un Haz y 47.06% para «U-Dos¼. En 11.76% de los pacientes se presentó un desplazamiento mayor a 11 mm en la rodilla afectada con KT-1000. En 8.82% se mostró un desplazamiento anterior igual en ambas rodillas. Un paciente presentó un desplazamiento anterior mayor posterior a la cirugía de reconstrucción con la técnica de Un Haz, pero con mejoría en las escalas clínicas. En las mediciones de Pivot Shift se encontró una diferencia en el desplazamiento mayor a los 4,000 m/s en el eje de las X tras la técnica de Un Haz en comparación con la rodilla sana calculando integrales, mientras que con U-Dos la diferencia fue menor de 600 m/s. En el eje de «Y¼ se encontró una diferencia 3,500 m/s entre la pierna sana y la lesionada, la cual disminuye a menos de 2,000 m/s tras la reconstrucción mediante técnica de U-Dos. CONCLUSIONES: A lo largo del estudio se han encontrado diferencias en la evolución de los pacientes que indican que la reparación mediante la técnica de U-Dos tiene mejores resultados al lograr recuperar la estabilidad anteroposterior y rotacional del miembro afectado.

Interpretación de la maniobra de pivote mediante el uso de acelerómetros en pacientes que acuden a consulta ortopédica / Interpretation of the pivot test using accelerometers in the orthopedic practice

Los ligamentos cruzados (LC) de la rodilla, anterior (A) y posterior (P), localizados dentro de la articulación, unen fémur y tibia, dando estabilidad sobre la dirección anteroposterior de un hueso sobre otro. El LCA puede lesionarse mediante rotaciones provocadas en algún deporte que implique giro con el pie apoyado sobre el suelo. Las lesiones del LCA se determinan con maniobras como la de Lachman, cajón y pivote. Se utilizan acelerómetros que permiten graficar la maniobra de pivote en pacientes que acuden a consulta ortopédica, utilizando la prueba de KT1000 como estándar de oro. El trabajo ha sido aprobado por el Comité de Ética del Hospital. Estudio descriptivo entre casos y controles. Resultados: 92 pacientes aceptaron participar mediante consentimiento informado, nueve casos resultaron con KT1000 positivo, de los negativos, seleccionamos nueve controles afines a edad y género. Alteraciones de KT1000 fueron mayores en mujeres (78%) y en 67% de los casos la pierna alterada fue la derecha. Los resultados promedio de KT1000 en casos fue de 5.44 mm, en controles de 0.66 mm. Los acelerómetros permitieron graficar la maniobra de pivote y observamos gráficas similares tanto en casos y controles, solamente se muestran diferencias notables en un paciente masculino con KT1000 de 15 mm que fue sometido a reparación de LCA izquierdo, la maniobra se realizó al estar sedado. Concluimos que el paciente, en estado consciente, pone resistencia en la maniobra, a diferencia de la obtenida con anestesia, y que el uso de acelerómetros permite documentar la maniobra de pivote observando diferencias entre un LCA normal y uno lesionado.

The anterior (A) and posterior (P) cruciate ligaments (CL) of the knee, located inside the joint, connect the femur and the tibia and thus provide stability in the anteroposterior axis of one bone over the other. The anterior cruciate ligament (ACL) may be injured as a result of rotation when practicing a sport involving turning with the foot on the ground. ACL injuries are diagnosed with maneuvers like the Lachman, drawer and pivot. Accelerometers were used to plot the pivot maneuver in patients seeing the orthopedist surgeon using the KT1000 test as gold standard. This case-control descriptive study was approved by the Hospital's Ethics Committee. Results: 92 patients accepted to participate through an informed consent; nine cases were KT1000 positive, and nine age- and gender-matched controls were selected among KT1000 negative patients. KT1000 alterations were greater among females (78%) and in 67% of cases the right leg was affected. Mean KT1000 results were 5.44 mm in cases and 0.66 mm in controls. Accelerometers allowed plotting the pivot maneuver and the resulting charts for cases and controls were similar. Remarkable differences were seen only in one male patient with a 15 mm KT1000, who underwent repair of the left ACL; the maneuver was performed under sedation. We concluded that conscious patients oppose the maneuver, unlike anesthetized patients, and that the use of accelerometers helps document the pivot maneuver which, in turn, helps detect differences between a normal ACL and an injured one.

[Interpretation of the pivot test using accelerometers in the orthopedic practice]. / Interpretación de la maniobra de pivote mediante el uso de acelerómetros en pacientes que acuden a consulta ortopédica.

The anterior (A) and posterior (P) cruciate ligaments (CL) of the knee, located inside the joint, connect the femur and the tibia and thus provide stability in the anteroposterior axis of one bone over the other. The anterior cruciate ligament (ACL) may be injured as a result of rotation when practicing a sport involving turning with the foot on the ground. ACL injuries are diagnosed with maneuvers like the Lachman, drawer and pivot. Accelerometers were used to plot the pivot maneuver in patients seeing the orthopedist surgeon using the KT1000 test as gold standard. This case-control descriptive study was approved by the Hospital's Ethics Committee. Results: 92 patients accepted to participate through an informed consent; nine cases were KT1000 positive, and nine age- and gender-matched controls were selected among KT1000 negative patients. KT1000 alterations were greater among females (78%) and in 67% of cases the right leg was affected. Mean KT1000 results were 5.44 mm in cases and 0.66 mm in controls. Accelerometers allowed plotting the pivot maneuver and the resulting charts for cases and controls were similar. Remarkable differences were seen only in one male patient with a 15 mm KT1000, who underwent repair of the left ACL; the maneuver was performed under sedation. We concluded that conscious patients oppose the maneuver, unlike anesthetized patients, and that the use of accelerometers helps document the pivot maneuver which, in turn, helps detect differences between a normal ACL and an injured one.

[Anterior cruciate ligament-plasty using the "U-dos" technique]. / Plastía de ligamento cruzado anterior con técnica de "U-Dos".

The knee is a compound diarthrodial joint, vulnerable to serious injuries such as ligament injuries of: medial collateral ligament, lateral collateral ligament, anterior cruciate ligament and posterior cruciate ligament, as cruciate ligaments limit rotation movement in the joint. The purpose of our study was to create a new technique to treat injuries of the anterior cruciate ligament, which is composed of two bundles--anteromedial and posterolateral--trying to achieve an anatomical reconstruction that allows for a normal biomechanical recovery. This technique reduces the use of fixation material and costs. The diagnosis of anterior cruciate ligament injuries was made with the pivot shift test. There are currently two repair methods for anterior cruciate ligament injuries: single bundle or double bundle repair; none of these techniques is considered as the gold standard, as their results are very similar. This paper describes a technique used for the treatment of anterior cruciate ligament injuries, known as "U-dos", and its clinical results. Cross-sectional, observational study that enrolled 20 patients with total anterior cruciate ligament injuries who underwent anterior cruciate ligament plasty using the "U-dos" technique between June 2009 and June 2010. The technique requires the use of bone bank allograft, in this case of the anterior tibial ligament. Patients were assessed using the Lysholm scale and the pivot shift test. Our results show that all the pivot shift tests were negative and assessments according to the Lysholm scale were from normal to excellent in 95% of cases (19/20). Only one failure was reported, with avulsion of the graft attachment which required a surgical intervention.

Rat peritoneal mast cells produce IFN-gamma following IL-12 treatment but not in response to IgE-mediated activation.

Mast cells have been reported to secrete a wide range of immunoregulatory cytokines following IgE-mediated activation and to play an important role in allergic inflammation. We have previously demonstrated that mast cells can also produce certain cytokines following activation with bacterial LPS or prostanoids without preformed mediator release. IL-12 is a potent inducer of IFN-gamma production by T cells and NK cells, and is thought to play a critical role in determining the nature of the local immune response to infection. We here report that highly purified peritoneal mast cells from Brown Norway rats will produce IFN-gamma in response to IL-12 without significant histamine release. IFN-gamma protein was detected by ELISA in supernatants of mast cells cultured with 2 U/ml recombinant mouse IL-12 for between 6 and 24 h. The production of IFN-gamma was dependent on the dose of IL-12 and was significantly inhibited by concurrent treatment with IL-10 or PGE2. Supernatants from IL-12-stimulated mast cells induced MHC class II expression on the mouse epithelial cell line, MODE-K, by an IFN-gamma-dependent mechanism. Peritoneal mast cells cultured following activation with anti-IgE or LPS, under conditions that will induce the production of IL-6, demonstrated no detectable protein production of IFN-gamma. We conclude that mast cells are capable of contributing to the IFN-gamma response to IL-12, but substantial mast cell IFN-gamma production does not occur as a result of IgE-mediated activation. These observations have important implications for the role of the mast cell in local immune regulation.

Interleukin (IL)-10 inhibits long-term IL-6 production but not preformed mediator release from rat peritoneal mast cells.

Mast cells have been implicated in a number of diseases involving chronic inflammation including asthma, rheumatoid arthritis, and inflammatory bowel diseases. They are a potent source of several cytokines, including IL-6 and TNF-alpha. Freshly isolated rat peritoneal mast cells will produce IL-6 in response to anti-IgE, LPS, PGE1, or PGE2; however, the mechanisms by which such cytokine production is regulated are poorly understood. IL-10 is recognized as an important immunoregulatory cytokine with effects on T cell development and the production of inflammatory cytokines. IL-10 has previously been described to enhance mast cell development in the context of IL-3 and IL-4. In the current study, we have examined the ability of IL-10 to modulate rat peritoneal mast cell IL-6 and TNF-alpha production in response to a variety of stimuli. We have observed that recombinant murine IL-10 can inhibit the production of both IL-6 and TNF-alpha by mast cells without altering the degree of histamine release in response to anti-IgE. Concentrations of IL-10 as low as 0.2 ng/ml were sufficient to inhibit IL-6 production by LPS- or anti-IgE-activated cells significantly. IL-10 also inhibited PGE1- and PGE2-induced IL-6 production. The relative potency of IL-10 as an inhibitor of mast cell IL-6 production was highly dependent upon the stimulus used, with a 10-fold difference in the IC50 for LPS- or anti-IgE-activated cells (0.21 ng/ml) and cells activated with a combination of LPS and PGE2 (2.29 ng/ml). This suggests that prostanoids may limit the ability of IL-10 to modulate mast cell IL-6 production in the context of inflammation. These data have important implications for the regulation of mast cell IL-6 in inflammatory diseases involving prostanoid production and the effects of treatment with cyclooxygenase inhibitors. Our results also demonstrate a dual role for IL-10 on mast cells as a growth factor and inhibitor of cytokine production.

Cholera toxin increases IL-6 synthesis and decreases TNF-alpha production by rat peritoneal mast cells.

Mast cells have been traditionally associated with an acute allergic response. However, their role in regulating chronic inflammatory processes must also be considered in view of evidence that mast cells synthesize and release a number of cytokines. In this study, we have examined the effect of cholera toxin (CT) on peritoneal mast cell IL-6 and TNF-alpha production. Highly purified, freshly isolated, rat peritoneal mast cells from Brown Norway rats were cultured in the presence of CT or its B subunit (CTB) alone or in combination with anti-IgE or bacterial LPS. Histamine release was measured after 10 min; IL-16 and TNF-alpha production was assessed in supernatants after 18 h. We found that CT or CTB alone did not affect histamine release; however, mast cell IL-6 production was significantly enhanced by CT but not by CTB. In contrast, constitutive production of TNF-alpha was inhibited by CT. The effects of CT were similar to our previous observations of the actions of prostaglandin E2 on mast cells. We also examined the effects of CT in combination with other mast cell activating agents. CT had no significant effect on anti-IgE-induced histamine release. An additive effect on IL-6 production was observed in the context of LPS. Forskolin, an agent known to increase intracellular cAMP levels, also induced a significant increase in IL-6 production, whereas TNF-alpha production was decreased. These data have important implications for our understanding of the regulation of mast cell cytokine production and the effects of CT on local cytokine production.

Prostanoid enhancement of interleukin-6 production by rat peritoneal mast cells.

Mast cells are traditionally associated with an acute response involving the short-term release of mediators such as histamine. We have shown previously that mast cells can produce IL-6 without prior histamine release. In this study we examined the hypothesis that mast cell IL-6 production can be selectively regulated by PGs. Highly purified rat peritoneal mast cells were cultured in the presence of PGE1, PGE2, or PGD2 alone or in combination with anti-IgE or bacterial LPS. Histamine release was assessed after 10 min; IL-6 and TNF-alpha production was measured in supernatants after 18 h. Mast cell IL-6 production was induced by PGE1 and PGE2 to a similar level to that observed in anti-IgE-activated cells. In contrast, constitutive production of TNF-alpha was inhibited by PGE1 and PGE2, but not by PGD2. PGE2 had a synergistic effect, inducing IL-6 in the presence of LPS, whereas an additive effect was observed in the presence of anti-IgE. None of the prostanoids alone induced significant histamine release at the 10-min time point. However, PGE2 significantly increased histamine release when added concurrently with anti-IgE. Flurbiprofen in the context of anti-IgE or LPS activation did not alter mast cell IL-6 or TNF-alpha production. IL-6 production in response to each of the stimuli was significantly inhibited by the corticosteroid dexamethasone. These observations of selective modulation of mast cell cytokine production are important to understand the mechanisms by which mast cells interact with other cells during an inflammatory process involving prostanoid synthesis.

IL-6 production by rat peritoneal mast cells is not necessarily preceded by histamine release and can be induced by bacterial lipopolysaccharide.

Mast cells produce a number of cytokines including IL-6. In view of the large amounts of de novo synthesis induced by the activation of rat peritoneal mast cells and previous observations of expression of this cytokine by human lung mast cells, we have studied the regulation of IL-6 production. We examined the hypothesis that mast cell IL-6 production is not related to previous histamine release. Highly purified rat peritoneal mast cells were activated with anti-IgE, calcium ionophore A23187, or LPS. Histamine was used as a marker of preformed mediator release and IL-6 production was assessed by using the B9 hybridoma growth factor bioassay. Anti-IgE activation of rat peritoneal mast cells induced IL-6 production and histamine release. In contrast, LPS activation induced substantial, serum-dependent, IL-6 production without a significant level of histamine release. No preformed IL-6 was detected in the cells. Calcium ionophore induced histamine release from mast cells to a greater extent than did anti-IgE, but no A23187-induced IL-6 production was observed. A23187-treated cells retained high viability and produced a significant amount of TNF-alpha. To further examine the concordance of IL-6 production and histamine release we used mast cell stabilizing drugs. Dexamethasone and nedocromil significantly inhibited IL-6 production in response to anti-IgE. Our results demonstrate that there is not a direct relationship between mast cell degranulation and IL-6 production. Our observations are important for understanding the role of mast cells in inflammation and for developing strategies to modulate mast cell function in disease.