Nonhomogeneous immunostaining of hyaline membranes in different manifestations of diffuse alveolar damage.

PURPOSE: To determine the nature of hyaline membranes in different manifestations of diffuse alveolar damage, [pulmonary and extrapulmonary acute respiratory distress syndrome], and idiopathic [acute interstitial pneumonia]. MATERIALS AND METHODS: Pulmonary specimens were obtained from 17 patients with acute respiratory distress syndrome and 9 patients with acute interstitial pneumonia. They were separated into 3 different groups: (a) pulmonary diffuse alveolar damage (pDAD) (n = 8), consisting only of pneumonia cases; (b) extrapulmonary diffuse alveolar damage (expDAI) (n = 9), consisting of sepsis and septic shock cases; and (c) idiopathic diffuse alveolar damage (iDAD) (n = 9), consisting of idiopathic cases (acute interstitial pneumonia). Hyaline membranes, the hallmark of the diffuse alveolar damage histological pattern, were examined using various kinds of antibodies. The antibodies used were against surfactant apoprotein-A (SP-A), cytokeratin 7 (CK7), cytokeratin 8 (CK8), alpha smooth muscle actin (alpha-SMA), cytokeratin AE1/AE3 (AE1/AE3), and factor VIII-related antigen (factor VIII). RESULTS: Pulmonary diffuse alveolar damage showed the largest quantity of hyaline membranes (12.65% +/- 3.24%), while extrapulmonary diffuse alveolar damage (9.52% +/- 3.64%) and idiopathic diffuse alveolar damage (7.34% +/- 2.11%) showed intermediate and lower amounts, respectively, with the difference being statistically significant between pulmonary and idiopathic diffuse alveolar damage (P < 0.05). No significant difference was found for hyaline membranes Sp-A immunostaining among pulmonary (15.36% +/- 3.12%), extrapulmonary (16.12% +/- 4.58%), and idiopathic (13.74 +/- 4.20%) diffuse alveolar damage groups. Regarding factor VIII, we found that idiopathic diffuse alveolar damage presented larger amounts of immunostained hyaline membranes (14.12% +/- 6.25%) than extrapulmonary diffuse alveolar damage (3.93% +/- 2.86%), with this difference being statistically significant (P < 0.001). Equally significant was the difference for progressive decrease of cytokeratin AE1/AE3 immunostaining in hyaline membranes present in the extrapulmonary diffuse alveolar damage (5.42% +/- 2.80%) and idiopathic diffuse alveolar damage (0.47% +/- 0.81%) groups (P < 0.001). None of the groups stained for cytokeratin CK-7, CK-8, vimentin, or a anti-smooth muscle actin. CONCLUSIONS: This study showed that only the epithelial/endothelial components (SP-A, factor VIII, and AE1/AE3) of the alveolar/capillary barrier are present in hyaline membranes formation in the 3 groups of patients with diffuse alveolar damage. The significant difference in the expression of factor VIII-related antigen and cytokeratin AE1/AE3 in the expDA versus iDAD groups as well as the significant difference in the amount of hyaline membranes present in the pDAD versus iDAD groups are suggestive of a local and specific lesion with different pathways (direct, indirect, or idiopathic), depending on the type of diffuse alveolar damage.

Nonhomogeneous immunostaining of hyaline membranes in different manifestations of diffuse alveolar damage / Imunomarcação não homogênea das membranas hialinas na sindrome da angustia respiratório do adulto pulmonar, extrapulmonar e idiopática

PURPOSE: To determine the nature of hyaline membranes in different manifestations of diffuse alveolar damage, [pulmonary and extrapulmonary acute respiratory distress syndrome], and idiopathic [acute interstitial pneumonia]. MATERIALS AND METHODS: Pulmonary specimens were obtained from 17 patients with acute respiratory distress syndrome and 9 patients with acute interstitial pneumonia. They were separated into 3 different groups: (a) pulmonary diffuse alveolar damage (pDAD) (n = 8), consisting only of pneumonia cases; (b) extrapulmonary diffuse alveolar damage (expDAI) (n = 9), consisting of sepsis and septic shock cases; and (c) idiopathic diffuse alveolar damage (iDAD) (n = 9), consisting of idiopathic cases (acute interstitial pneumonia). Hyaline membranes, the hallmark of the diffuse alveolar damage histological pattern, were examined using various kinds of antibodies. The antibodies used were against surfactant apoprotein-A (SP-A), cytokeratin 7 (CK7), cytokeratin 8 (CK8), alpha smooth muscle actin (a-SMA), cytokeratin AE1/AE3 (AE1/AE3), and factor VIII-related antigen (factor VIII). RESULTS: Pulmonary diffuse alveolar damage showed the largest quantity of hyaline membranes (12.65 percent ± 3.24 percent), while extrapulmonary diffuse alveolar damage (9.52 percent ± 3.64 percent) and idiopathic diffuse alveolar damage (7.34 percent ± 2.11 percent) showed intermediate and lower amounts, respectively, with the difference being statistically significant between pulmonary and idiopathic diffuse alveolar damage (P < 0.05). No significant difference was found for hyaline membranes Sp-A immunostaining among pulmonary (15.36 percent ± 3.12 percent), extrapulmonary (16.12 percent ± 4.58 percent), and idiopathic (13.74 ± 4.20 percent) diffuse alveolar damage groups. Regarding factor VIII, we found that idiopathic diffuse alveolar damage presented larger amounts of immunostained hyaline membranes (14.12 percent ± 6.25 percent) than extrapulmonary diffuse alveolar damage...

OBJETIVO: Determinar a natureza da membrana hialina nas diferentes manifestações do dano alveolar difuso [pulmonar e extrapulmonar síndrome do desconforto respiratório] e idiopático [pneumonia intersticial aguda]. MATERIAIS E MÉTODOS: Espécimes pulmonares foram obtidos de 17 pacientes com SDRA e 9 pacientes com pneumonia intersticial aguda e separados em três diferentes grupos: (a) dano alveolar difuso pulmonar (DADp) (n=8) constituído por casos de pneumonia, (b) dano alveolar difuso extrapulmonar (DADexp) (n=9) constituído por casos de sepse e choque séptico e (c) dano alveolar difuso idiopático (DADi) (n=9) constituído por casos idopáticos (ou pneumonia intersticial aguda). As características das membranas hialinas do padrão histológico de dano alveolar difuso foram examinadas usando vários tipos de anticorpos. Os anticorpos usados foram surfactante apoproteina A (SP-A), anti-citokeratina 7 (CK7), citokeratina 8 (CK8), alfa actina de músculo liso (a-SMA), citokeratina AE1/AE3 (AE1/AE3) e antígeno relacionado ao fator VIII (Fator VIII). RESULTADOS: Observaram-se aumentos maiores da quantidade de membrana hialina no dano alveolar difuso pulmonar (12.65 ± 3.24 por cento), intermediários no dano alveolar difuso extrapulmonar (9.52 ± 3.64 por cento) e baixos no dano alveolar difuso idiopático (7.34 ± 2.11 por cento) respectivamente, esta diferencia foi estatística significante entre o dano alveolar difuso pulmonar e o dano alveolar difuso idiopático (p<0.05). Não se encontrou significância estatística para a quantidade de imunomarcação de Sp-A nos grupos de dano alveolar difuso pulmonar (15.36 ± 3.12 por cento), extrapulmonar (16.12 ± 4.58 por cento) e idiopático (13.74 ± 4.20 por cento). Com relação ao Fator VIII, nós encontramos maiores aumentos da imunomarcação da membrana hialina no grupo dano alveolar difuso idiopático (14.12 ± 6.25 por cento) do que no dano alveolar difuso extrapulmonar (3.93 ± 2.86 por cento), com significância estatística (p<0.001). Da mesma...