Association of female sex and positive rheumatoid factor with low serum infliximab and anti-drug antibodies, related to treatment failure in early rheumatoid arthritis: results from the SWEFOT trial population.

Objective: Infliximab-treated patients with rheumatoid arthritis (RA) may respond insufficiently due to low serum infliximab (sIFX) levels, caused by anti-drug antibodies (ADAs). However, monitoring of sIFX and ADAs is not routinely implemented, and levels for optimal outcome have not been validated. We searched for predictors for sIFX < 0.2 µg/mL and ADA development in a randomized setting. Methods: In the SWEFOT trial, of 128 patients randomized to methotrexate + IFX therapy, 101 had serum samples at 3, 9, and 21 months that were analysed for sIFX [enzyme-linked immunosorbent assay (ELISA)] and ADAs [ELISA, and precipitation and acid dissociation (PandA) when sIFX > 0.2 µg/mL]. The primary and secondary outcome measures were low disease activity [LDA = 28-joint Disease Activity Score (DAS28) ≤ 3.2] and remission (DAS28 < 2.6). Baseline characteristics were assessed as potential predictors of sIFX < 0.2 µg/mL or ADA positivity, using logistic regression. Results: Categorization of sIFX levels into < 0.2, 0.2-2.9, 3.0-7.0, and > 7.0 µg/mL showed a dose-response association with LDA (30%, 64%, 67%, and 79%, respectively, p = 0.008) and remission (10%, 45%, 39%, and 66%, p = 0.004) at trial cessation (21 months). Female patients had sIFX < 0.2 µg/mL more often than males (35% vs 7%, p = 0.006), with a similar trend for rheumatoid factor (RF)-positive vs RF-negative patients (34% vs 16%, p = 0.059). ADA positivity showed similar patterns, also after adjustment for potential confounders (female sex: p = 0.050; RF positivity: p = 0.067). PandA captured four highly ADA-reactive patients with sIFX > 0.2 µg/mL, of whom three were ADA positive at other time-points, all with high DAS28 at follow-up. Conclusion: In early RA patients receiving IFX as a second-line agent, sIFX < 0.2 µg/mL and ADA development were associated with treatment failure and were more common in females, with a similar trend for RF positivity. Our findings support the use of therapeutic drug monitoring, and PandA in ADA-negative non-responders. Trial registration: SWEFOT NCT00764725 ( https://clinicaltrials.gov/ct2/show/NCT00764725 ).

The role of IL-1beta in reduced IL-7 production by stromal and epithelial cells: a model for impaired T-cell numbers in the gut during HIV-1 infection.

OBJECTIVES: Interleukin (IL)-7 is a key cytokine in T-cell homeostasis. Stromal cells, intestinal epithelial cells and keratinocytes are known to produce this cytokine. The mechanisms and cellular factors regulating IL-7 production are still unclear. We assessed whether IL-1beta and interferon (IFN)-gamma, cytokines produced during inflammatory conditions, may impact on IL-7 production. DESIGN: We used human intestinal epithelial cells (DLD-1 cell line) and bone marrow stromal cells (HS27 cell line), known to produce IL-7; IL-7 production was evaluated at the mRNA and protein levels. To assess whether treatment of HS27 cells with IL-1beta and/or IFN-gamma leads to changes in the gene expression of cytokines, Toll-like receptors (TLRs) and chemokines, we analysed gene expression profiles using the whole-genome microarray Human Gene 1.0 ST. RESULTS: We found that IFN-gamma enhanced the expression of IL-7 mRNA (P < 0.001) in both cell lines. IL-1beta treatment led to a significant down-regulation (P < 0.001) of IL-7 mRNA expression in both cell lines. The IL-7 concentration in supernatants collected from treated DLD-1 and HS27 cell cultures reflected the trend of IL-7 mRNA levels. The gene profiles revealed dramatic changes in expression of cytokines and their receptors (IL-7/IL-7R alpha; IL-1alpha,IL-1beta/IL-1R1; IFN-gamma/IFN-gammaR1), of IFN regulatory factors (IRF-1 and 2), of TLRs and of important chemo-attractants for T cells. The microarray results were verified by additional methods. CONCLUSIONS: Our results are discussed in the setting of inflammation and T-cell survival in the gut compartment during HIV-1 infection where stromal and epithelial cells may produce factors that contribute to impaired IL-7 homeostasis and homing of T cells.

Desprendimiento de proplaquetas en el sinuoside a través de las fenestraciones / Projections of platelets throught fenestrations to sinuosoidal circulation

Los megacariocitos producen formaciones citoplasmáticaspseudopódicas grandes llamadas proplaquetas. En nuestroestudio ultraestructural en microscopía electrónica de biopsiasde médula ósea en personas normales, hemos encontrado quelas proplaquetas son muy ricas en membranas de demarcacióny gránulos y tienen una estructura microfibrilar única alojada enel interior, pasan a la circulación sinusoidal a través de lasfenestraciones, que son poros funcionales del endotelio. Unavez en la circulación las membranas de demarcación de las proplaquetasse abren y estas sufren una elongación en forma arosariada,es decir con estructuras esferoidales secuenciales,cada una de esas esferas se separa y forma la plaqueta. Laestructura microfibrilar en la proplaqueta es única y se polimerizapara formar un anillo microfibrilar periférico en cada plaqueta,que le da su forma discoide

In our study in electron microscopy of bone marrow biopsiesof normal persons, we found that the megakaryocytes developedmultiple pseudopodal-projections derived from their peripheralzone, called proplatelets. These projections passthrough the pores of the endothelium, called fenestrations, andreached the sinusoidal circulation. Once in the lumen the proplateletssuffer elongations. The beaded elongations are rich ingranules, and demarcation membranes, which delimit the plateletterritories during fragmentation. The microtubular structureis scarce, appears as a single structure inside the cytoplasmof the proplatelet, acts as a nucleation center, and whenthe beaded elongations are produced this structure polymerizesand grows, forming peripheral coiles in the platelets thatgive them the discoid shape

Malignant salivary gland tumors in Quito, Ecuador.

OBJECTIVES: Malignant salivary gland tumors (MSGT) are uncommon. Age-standardized incidence rates are 0.5 and 0.3 per 100,000 in Quito, Ecuador; and 1.0 and 0.7 per 100,000 in the USA (SEER Program), for males and females, respectively. The goal of this study was to review a 16-year experience of a major general hospital in the treatment of these lesions. PATIENTS AND METHODS: From 1982 to 1998, 308 salivary gland tumors were surgically treated at the Hospital 'Carlos Andrade Marin' of the Ecuadorian Institute of Social Security in Quito, Ecuador, an Andean city of approximately 2 million inhabitants. Malignant lesions were found in 58 cases (19%): 37 out of 194 parotid gland tumors (19%), 7 out of 86 submandibular tumors (8%) and 14 out of 28 minor salivary gland tumors (50%). Adenoid cystic carcinoma and mucoepidermoid carcinoma were the most common histologic types. Twenty-two cases were classified as stage I, 13 as stage II, 1 as stage III and 20 as stage IV (UICC TNM staging classification). Thirty-one (53%) patients were treated by surgery alone; postoperative radiation therapy was additionally given to 22 (38%), and surgery, radiotherapy and chemotherapy were applied in 5 cases (9%). RESULTS: Local (LR) and/or regional recurrences were detected in 13 patients (22%). Twelve patients (21%) developed distant metastasis (DM; 2 in more than one site): 7 in the lungs, 2 in the brain, 2 in the bone and 1 each in the liver, subcutaneous tissue and pleura. Thirty-five patients are alive, 33 disease free. Twenty-three patients are deceased: 6 with LR, 7 with DM, 3 with both LR and DM, 1 with locoregional recurrence and DM, 2 with a second neoplasm, 3 with intercurrent disease and 1 from unknown causes. Five- and 10-year overall survival rates were 75 and 68%, respectively. There were no significant differences in mortality according to the site of the primary tumor or histologic type, but stage and involved surgical margins were important prognostic factors (p = 0.006 and 0.003). CONCLUSIONS: The surgical or multimodality treatment of MSGT has provided a good locoregional control (78%) and 68% 10-year survival in a series of patients treated at the oncology department of a general hospital in Quito, Ecuador. Stage and involved surgical margins were significant prognostic factors.

Role of the microtubular system in platelet aggregation.

1. Four structural systems are involved in the process of platelet activation that leads to aggregation: 1) the membrane system, i.e., the cytoplasmic membrane, the dense tubular structure and the open canalicular structure; 2) alpha and dense granules; 3) the peripheral microtubular coils; 4) the microfibrillar meshwork of actin-myosin bundles. 2. We added four compounds which modify cell ultrastructure to normal platelet-rich plasma to analyze the behavior of the structural systems of platelet activation: vinblastine (100 micrograms/ml) and cimetidine (100 micrograms/ml) that act on the membrane system, ticlopidine (200 micrograms/ml) and colchicine (100 micrograms/ml) that affect primarily the microtubular structure, cytochalasin B (30 micrograms/ml) and phorbol myristate acetate (100 ng/ml) that act upon the granular system, and cytochalasin D (30 micrograms/ml) and concanavalin A (50 micrograms/ml) that influence the microfibrillar structure. Platelet aggregation was stimulated by epinephrine or thrombin. 3. Cimetidine and ticlopidine prevented aggregation. However, neither substance affected the microtubular structure. Colchicine and cytochalasin B only partially impaired aggregation, because pieces of microtubules remained in the presence of these substances. The other substances did not present anti-aggregant activity and did not preserve the microtubules. 4. We infer that the disappearance of the microtubules is necessary to produce aggregation. When they remain intact no aggregation is produced, even though the other structural systems are activated.

Role of the microtubular system in platelet aggregation

1. Four structural systems are involved in the process of platelet activation that leads to aggregation: 1) the membrane system, i.e., the cytoplasmic membrane, the dense tubular structure and the open canalicular structure; 2) alpha and dense granules; 3) the peripheral microtubular coils; 4) the microfibrillar meshwork of actin-myosin bundles. 2. We added four compounds which modify cell ultrastructure to normal platelet-rich plasma to analyze the behavior of the structural systems of platelet activation: vinblastine (100 micrograms/ml) and cimetidine (100 micrograms/ml) that act on the membrane system, ticlopidine (200 micrograms/ml) and colchicine (100 micrograms/ml) that affect primarily the microtubular structure, cytochalasin B (30 micrograms/ml) and phorbol myristate acetate (100 ng/ml) that act upon the granular system, and cytochalasin D (30 micrograms/ml) and concanavalin A (50 micrograms/ml) that influence the microfibrillar structure. Platelet aggregation was stimulated by epinephrine or thrombin. 3. Cimetidine and ticlopidine prevented aggregation. However, neither substance affected the microtubular structure. Colchicine and cytochalasin B only partially impaired aggregation, because pieces of microtubules remained in the presence of these substances. The other substances did not present anti-aggregant activity and did not preserve the microtubules. 4. We infer that the disappearance of the microtubules is necessary to produce aggregation. When they remain intact no aggregation is produced, even though the other structural systems are activated.

Thrombocytopathy due to a defect of the platelet membrane complex.

A new type of primary thrombocytopathy is described. Three main alterations were found: (1) a defect of the aggregation reaction with ADP, epinephrine and collagen and a normal response to ristocetin and arachidonic acid; (2) a moderate deficiency of platelet procoagulant activity, and (3) a combined hypertrophy of the two membrane systems of the platelet--the open canalicular and the dense tubular. The latter defect is shown as an abnormal membrane complex situated on one of the platelet poles. This thrombocytopathy is discussed as a new variety of primary platelet disorder.

Analysis of the ultrastructure of the platelets during the process of aggregation, with emphasis in the cytoskeleton and membranous changes

In this paper we presetn our findings in relation to the ultrastructural changes that are produced in the platelets during the hemostatic activation process. When the platelets are in the resting stage they have a discoid form with are a peripheral microtubular structure that encloses numerous granules, showing an open canalicular system spreading throughout the cytoplasm. Once they are activated, sequential morphological changes take place. First of all, the microtubular structure desintegrates and is replaced by a membranous pseudotubular membranous complex which fuses itself to the granules enhancing the open canalicular system which grows until it takes a sacular-canalicular appearance. Degranulation takes place at the same time. The from of the platelets becomes spherical and irregular. Later on, a microfilament organization appears, specially in the peripheral zozne projecting into the pseudopodical prolongations which are formed in the surface, giving the platelets a very irregular filopoidal form. Finally they loose all their structure becoming hyaline and vacuolated. We believe that the pseudopodical stage is the last step of the activation, prvious to the final vacuolization and destruction

Analysis of the ultrastructure of the platelets during the process of aggregation, with emphasis in the cytoskeleton and membranous changes

In this paper we presetn our findings in relation to the ultrastructural changes that are produced in the platelets during the hemostatic activation process. When the platelets are in the resting stage they have a discoid form with are a peripheral microtubular structure that encloses numerous granules, showing an open canalicular system spreading throughout the cytoplasm. Once they are activated, sequential morphological changes take place. First of all, the microtubular structure desintegrates and is replaced by a membranous pseudotubular membranous complex which fuses itself to the granules enhancing the open canalicular system which grows until it takes a sacular-canalicular appearance. Degranulation takes place at the same time. The from of the platelets becomes spherical and irregular. Later on, a microfilament organization appears, specially in the peripheral zozne projecting into the pseudopodical prolongations which are formed in the surface, giving the platelets a very irregular filopoidal form. Finally they loose all their structure becoming hyaline and vacuolated. We believe that the pseudopodical stage is the last step of the activation, prvious to the final vacuolization and destruction (AU)