Risk factors of pelvic pressure ulcer recurrence after primary skin flap surgery in people with spinal cord injury.

BACKGROUND: Flap surgery for deep pelvic pressure ulcers (PPUs) has been found effective, but the recurrence rate remains high and few risk factors have been identified. OBJECTIVE: We evaluated risk factors for PU recurrence after primary flap surgery in people with spinal cord injury (SCI). PATIENTS AND METHODS: This observational retrospective study based on medical charts included all individuals with SCI who underwent primary flap surgery for a PPU in the Hérault department in France between 2006 and 2014. Overall, 100 biomedical, psychological, socioeconomic and care management factors were studied. The primary outcome was PPU recurrence (surgical site and/or other pelvic site). The secondary outcome was recurrence at the surgical site. Cox proportional hazards regression was used to determine associated factors, estimating hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: We included 85 patients. Half had a PPU recurrence, and in one-third, the recurrence was at the surgical site. On multivariate analysis, global PPU recurrence was associated with colostomy (HR=2.79) and living with a partner (HR=2.29). Non-traumatic SCI and sacral wound were associated with PPU recurrence (HR=3.39, HR=0.48) and recurrence at the surgical site (HR=3.3, HR=0.3). CONCLUSION: Risk factors of PPU recurrence are based on both biomedical and social models. After primary flap surgery, the risk of recurrence justifies regular follow-up and strict monitoring.

Immunotherapeutic maintenance treatment with toll-like receptor 9 agonist lefitolimod in patients with extensive-stage small-cell lung cancer: results from the exploratory, controlled, randomized, international phase II IMPULSE study.

Background: The immune surveillance reactivator lefitolimod (MGN1703), a DNA-based TLR9 agonist, might foster innate and adaptive immune response and thus improve immune-mediated control of residual cancer disease. The IMPULSE phase II study evaluated the efficacy and safety of lefitolimod as maintenance treatment in extensive-stage small-cell lung cancer (ES-SCLC) after objective response to first-line chemotherapy, an indication with a high unmet medical need and stagnant treatment improvement in the last decades. Patients and methods: 103 patients with ES-SCLC and objective tumor response (as per RECIST 1.1) following four cycles of platinum-based first-line induction therapy were randomized to receive either lefitolimod maintenance therapy or local standard of care at a ratio of 3 : 2 until progression or unacceptable toxicity. Results: From 103 patients enrolled, 62 were randomized to lefitolimod, 41 to the control arm. Patient demographics and response patterns to first-line therapy were balanced. Lefitolimod exhibited a favorable safety profile and pharmacodynamic assessment confirmed the mode-of-action showing a clear activation of monocytes and production of interferon-gamma-induced protein 10 (IP-10). While in the intent-to-treat (ITT) population no relevant effect of lefitolimod on progression-free and overall survival (OS) could be observed, two predefined patient subgroups indicated promising results, favoring lefitolimod with respect to OS: in patients with a low frequency of activated CD86+ B cells (hazard ratio, HR 0.53, 95% CI: 0.26-1.08; n = 38 of 88 analyzed) and in patients with reported chronic obstructive pulmonary disease (COPD) (HR 0.48, 95% CI: 0.20-1.17, n = 25 of 103). Conclusions: The IMPULSE study showed no relevant effect of lefitolimod on the main efficacy end point OS in the ITT, but (1) the expected pharmacodynamic response to lefitolimod, (2) positive OS efficacy signals in two predefined subgroups and (3) a favorable safety profile. These data support further exploration of lefitolimod in SCLC.

CD1d-dependent immune suppression mediated by regulatory B cells through modulations of iNKT cells.

Regulatory B cells (Breg) express high levels of CD1d that presents lipid antigens to invariant natural killer T (iNKT) cells. The function of CD1d in Breg biology and iNKT cell activity during inflammation remains unclear. Here we show, using chimeric mice, cell depletion and adoptive cell transfer, that CD1d-lipid presentation by Bregs induces iNKT cells to secrete interferon (IFN)-γ to contribute, partially, to the downregulation of T helper (Th)1 and Th17-adaptive immune responses and ameliorate experimental arthritis. Mice lacking CD1d-expressing B cells develop exacerbated disease compared to wild-type mice, and fail to respond to treatment with the prototypical iNKT cell agonist α-galactosylceramide. The absence of lipid presentation by B cells alters iNKT cell activation with disruption of metabolism regulation and cytokine responses. Thus, we identify a mechanism by which Bregs restrain excessive inflammation via lipid presentation.

Standardizing terms, definitions and concepts for describing and interpreting unwanted immunogenicity of biopharmaceuticals: recommendations of the Innovative Medicines Initiative ABIRISK consortium.

Biopharmaceuticals (BPs) represent a rapidly growing class of approved and investigational drug therapies that is contributing significantly to advancing treatment in multiple disease areas, including inflammatory and autoimmune diseases, genetic deficiencies and cancer. Unfortunately, unwanted immunogenic responses to BPs, in particular those affecting clinical safety or efficacy, remain among the most common negative effects associated with this important class of drugs. To manage and reduce risk of unwanted immunogenicity, diverse communities of clinicians, pharmaceutical industry and academic scientists are involved in: interpretation and management of clinical and biological outcomes of BP immunogenicity, improvement of methods for describing, predicting and mitigating immunogenicity risk and elucidation of underlying causes. Collaboration and alignment of efforts across these communities is made difficult due to lack of agreement on concepts, practices and standardized terms and definitions related to immunogenicity. The Innovative Medicines Initiative (IMI; www.imi-europe.org), ABIRISK consortium [Anti-Biopharmaceutical (BP) Immunization Prediction and Clinical Relevance to Reduce the Risk; www.abirisk.eu] was formed by leading clinicians, academic scientists and EFPIA (European Federation of Pharmaceutical Industries and Associations) members to elucidate underlying causes, improve methods for immunogenicity prediction and mitigation and establish common definitions around terms and concepts related to immunogenicity. These efforts are expected to facilitate broader collaborations and lead to new guidelines for managing immunogenicity. To support alignment, an overview of concepts behind the set of key terms and definitions adopted to date by ABIRISK is provided herein along with a link to access and download the ABIRISK terms and definitions and provide comments (http://www.abirisk.eu/index_t_and_d.asp).

Salivary steroid hormone response to whole-body cryotherapy in elite rugby players.

Saliva represents a low stress, not-invasively collected matrix that allows steroid hormone monitoring in athletes by reflecting type, intensity and duration of exercise. Whole body cryotherapy (WBC) consists of short whole-body exposures to extremely cold air (-110° to -140°C) which, despite being initially used to treat inflammatory diseases, is currently acquiring increasing popularity in sports medicine. Cryostimulation practice is now widely accepted as an effective treatment to accelerate muscle recovery in rugby players. The aim of this work was to study the changes of steroid hormones in saliva of rugby players after both 2 and 14 consecutive WBC sessions, in order to investigate the effects of the treatment on their salivary steroid hormonal profile. Twenty-five professional rugby players, belonging to the Italian National Team, underwent a 7-day cryotherapy protocol consisting of 2 daily sessions. Saliva samples were taken in the morning prior to the start of the WBC, in the evening after the end of the second WBC, and in the morning of the day after the last WBC session. The samples were analyzed for cortisol, DHEA, testosterone and estradiol using competitive enzyme-linked immunosorbent assays. Cortisol and DHEA showed a reduction already after the 2 WBC sessions of the first day; after 14 consecutive WBC sessions cortisol, DHEA, and estradiol levels decreased, while testosterone increased as did the testosterone to cortisol ratio. These results were confirmed by the fact that the majority of subjects showed variations exceeding the critical difference (CD). In conclusion, we found that WBC acutely affects the salivary steroid hormone profile, and the results are evident already after only one twice-daily session. Most significantly, after one-week of consecutive twice-daily WBC sessions, all the hormones were modified. This is the first experimental report that links changes in the hormonal asset to WBC.

Influence of age and physical exercise on sirtuin activity in humans.

Sirtuins are NAD+-dependent lysine deacetylases. Sirtuins acquired worldwide attention because of their ability to increase yeast, flies, worms and mice lifespan. Recently, this assumption has been challenged. However, their beneficial role on the quality of ageing is widely accepted. In this work we aimed to study how and if sirtuins expression and activity levels varies in function of age and, in the case of young subjects, of exercise. Fifteen blood donors of different ages and fifteen athletes of the Italian rowing male team were enrolled and peripheral blood mononuclear cells (PBMCs) isolated from blood samples. Our results show that sirtuins deacetylases activity measured in PBMCs increases from 18 to 40 years of age and then decreases during the following 20 years. Moreover, physical exercise in professional athletes can upregulate sirtuin activity. Thus, for the first time in humans, we demonstrate that sirtuin activity is a function of age and can be altered through physical exercise.

Positive predictive value for malignancy on surgical excision of breast lesions of uncertain malignant potential (B3) diagnosed by stereotactic vacuum-assisted needle core biopsy (VANCB): a large multi-institutional study in Italy.

Percutaneous core biopsy (CB) has been introduced to increase the ability of accurately diagnosing breast malignancies without the need of resorting to surgery. Compared to conventional automated 14 gauge needle core biopsy (NCB), vacuum-assisted needle core biopsy (VANCB) allows obtaining larger specimens and has recognized advantages particularly when the radiological pattern is represented by microcalcifications. Regardless of technical improvements, a small percentage of percutaneous CBs performed to detect breast lesions are still classified, according to European and UK guidelines, in the borderline B3 category, including a group of heterogeneous lesions with uncertain malignant potential. We aimed to assess the prevalence and positive predictive values (PPV) on surgical excision (SE) of B3 category (overall and by sub-categories) in a large series of non-palpable breast lesions assessed through VANCB, also comparison with published data on CB. Overall, 26,165 consecutive stereotactic VANCB were identified in 22 Italian centres: 3107 (11.9%) were classified as B3, of which 1644 (54.2%) proceeded to SE to establish a definitive histological diagnosis of breast pathology. Due to a high proportion of microcalcifications as main radiological pattern, the overall PPV was 21.2% (range 10.6%-27.3% for different B3 subtypes), somewhat lower than the average value (24.5%) from published studies (range 9.9%-35.1%). Our study, to date the largest series of B3 with definitive histological assessment on SE, suggests that B3 lesions should be referred for SE even if VANCB is more accurate than NCB in the diagnostic process of non-palpable, sonographically invisible breast lesions.

[The family context in end-of-life is a resource to know and support: some reflections]. / Il contesto familiare del malato terminale è una risorsa da conoscere e supportare: alcune riflessioni.

The family caregiver role is a vital element of home-based patient care. At home, the achievement of the care plan may depend on the physician's relationship with the patient's caregiving network. Caregivers often tolerate an incalculable emotional burden for their work. Although many enjoy a profound sense of benefit and get deep satisfaction in this role, sadness, guilt, anger, resentment, and a sense of inadequacy are also common and understandable reactions. Exhaustion, financial strain, disrupted usual activities, and continuous caregiving contribute to significant mental health morbidity, including anxiety and depression. Early recognition of caregiver distress, help to secure a trusting partnership between the physician and the patient-caregiver unit at the end of life. This paper give some suggestion coming from a decade of support to families during the end stage.

Haematological parameters in elite rugby players during a competitive season.

We assessed haematological parameters and possible modifications in elite rugby players throughout a competitive season for increasing the knowledge of physiological characteristics of these sportsmen. Blood samples were collected from the members of the Italian National rugby team at four consecutive training camps during a whole competitive season. Forty-four athletes were recruited for the first camp, 36 for the second, 30 for the third and 32 for the fourth. Due to turnover of the subjects during the season only 13 athletes could be examined at all four camps, and another six in the first three camps. Therefore, we selected the data of these 19 athletes. Iron and transferrin saturation were stable, whilst ferritin increased at the end of the season. The modifications of the soluble transferrin receptor (sTFR) were linked to those of haematocrit: sTFR increased after training and during the competition period when haemoglobin and haematocrit decreased, and decreased at the end of the season. Haemoglobin and haematocrit showed slightly higher levels during the first part of the season and decreased in the second half, when physical demand was high, as demonstrated by biochemical additional tests. Leucocytes and platelets were stable throughout the season. Haematological and iron metabolism parameters in the elite rugby players examined during a whole season fall within physiological range of values. The variability of the parameters during the season is related to training and competition workload. Reticulocytes and sTFR are the most sensitive parameters for studying the iron metabolism of the athletes.

Therapeutic activity of agonistic monoclonal antibodies against CD40 in a chronic autoimmune inflammatory process.

The use of agonistic monoclonal antibody against CD40 has emerged as one the most effective ways to boost immune responses against infectious agents or to fight cancer. Here, we report that the same monoclonal antibodies against CD40 (FGK45 and 3/23) previously used to elicit protective immune responses treated the autoimmune inflammatory process of chronic collagen-induced arthritis in DBA/1-TCR-beta transgenic mice, as well as collagen-induced arthritis in DBA/1 mice, both animal models of rheumatoid arthritis. This study indicates that agonistic monoclonal antibody against CD40 can potentially be used to treat chronic autoimmune inflammatory processes.

A comparative study into the mechanisms of action of anti-tumor necrosis factor alpha, anti-CD4, and combined anti-tumor necrosis factor alpha/anti-CD4 treatment in early collagen-induced arthritis.

OBJECTIVE: Anti-tumor necrosis factor alpha (anti-TNFalpha) therapy is very effective in rheumatoid arthritis (RA), whereas depleting anti-CD4 therapy is relatively ineffective. To explain the differences in efficacy between these 2 therapies, we used an animal model of RA to compare their effects on different aspects of the disease process. METHODS: Mice with collagen-induced arthritis were treated with depleting anti-CD4 monoclonal antibodies (mAb), anti-TNFalpha mAb, or phosphate buffered saline. Another group was given a combination of anti-TNFalpha plus anti-CD4. The treatments were compared for their ability to down-regulate the expression of proinflammatory cytokines and adhesion molecules, reduce the cellularity of the joint, and inhibit Th1 activity. RESULTS: Anti-TNFalpha significantly reduced the numbers of cells expressing TNFalpha, interleukin-1beta (IL-1beta), very late activation antigen 4 (VLA-4), vascular cell adhesion molecule 1 (VCAM-1), and numbers of CD4+ T cells and macrophages in the joint. Anti-CD4 treatment led to a small reduction in the expression of TNFalpha, IL-1beta, VLA-4, and VCAM-1, but this did not reach statistical significance. Depleting anti-CD4 was also surprisingly ineffective in eliminating CD4+ T cells from the joint. Anti-TNFalpha therapy was also more effective than anti-CD4 in reducing Thl activity, as assessed by the production of interferon-gamma in lymph node cell cultures. There was a synergistic relationship between anti-TNFalpha and anti-CD4 in the reduction of histologic score and inhibition of TNFalpha/IL-1beta expression in the joints. CONCLUSION: The efficacy of the 3 treatments correlated with their ability to modulate the expression of inflammatory cytokines and adhesion molecules in the joint, reduce the cellularity of the joint, and inhibit Th1 activity. This kind of analysis may prove useful in the testing of novel therapies for RA.

Therapeutic actions of cyclosporine and anti-tumor necrosis factor alpha in collagen-induced arthritis and the effect of combination therapy.

OBJECTIVE: To define the mechanisms of action of 2 novel drugs, cyclosporine and anti-tumor necrosis factor alpha (TNFalpha), in collagen-induced arthritis and to determine the effect of combination therapy. METHODS: Type II collagen-immunized DBA/1 mice with established arthritis were treated with cyclosporine alone, anti-TNFalpha alone, cyclosporine plus anti-TNFalpha, or saline. RESULTS: Cyclosporine was found to ameliorate arthritis, suppress interferon-gamma (IFNgamma) production by CD4+ T cells, and reduce TNFalpha expression in arthritic joints. However, cyclosporine did not directly inhibit TNFalpha production by macrophages, indicating that the decrease in TNFalpha expression observed in vivo was probably an indirect consequence of the reduction in type 1 T helper cell activity. Anti-TNFalpha also reduced IFNgamma production by T cells, indicating that TNFalpha is involved in the cellular immune response to collagen. Combined treatment with cyclosporine plus anti-TNFalpha had an additive therapeutic effect. CONCLUSION: Although cyclosporine and anti-TNFalpha target different points in the inflammatory pathway, there is an overlap in the consequences of their actions in vivo.

Importance of cyclophosphamide-induced bystander effect on T cells for a successful tumor eradication in response to adoptive immunotherapy in mice.

Cyclophosphamide (CTX) increases the antitumor effectiveness of adoptive immunotherapy in mice, and combined immunotherapy regimens are now used in some clinical trials. However, the mechanisms underlying the synergistic antitumor responses are still unclear. The purpose of this study was (a) to evaluate the antitumor response to CTX and adoptive immunotherapy in mice bearing four different syngeneic tumors (two responsive in vivo to CTX and two resistant); and (b) to define the mechanism(s) of the CTX-immunotherapy synergism. Tumor-bearing DBA/2 mice were treated with a single injection of CTX followed by an intravenous infusion of tumor-immune spleen cells. In all the four tumor models, a single CTX injection resulted in an impressive antitumor response to the subsequent injection of spleen cells from mice immunized with homologous tumor cells independently of the in vivo response to CTX alone. Detailed analysis of the antitumor mechanisms in mice transplanted with metastatic Friend leukemia cells revealed that (a) the effectiveness of this combined therapy was dependent neither on the CTX-induced reduction of tumor burden nor on CTX-induced inhibition of some putative tumor-induced suppressor cells; (b) the CTX/immune cells' regimen strongly protected the mice from subsequent injection of FLC, provided the animals were also preinoculated with inactivated homologous tumor together with the immune spleen cells; (c) CD4(+) T immune lymphocytes were the major cell type responsible for the antitumor activity; (d) the combined therapy was ineffective in mice treated with antiasialo-GM1 or anti-IFN-alpha/beta antibodies; (e) spleen and/ or bone marrow cells from CTX-treated mice produced soluble factors that assisted in proliferation of the spleen cells. Altogether, these results indicate that CTX acts via bystander effects, possibly through production of T cell growth factors occurring during the rebound events after drug administration, which may sustain the proliferation, survival, and activity of the transferred immune T lymphocytes. Thus, our findings indicate the need for reappraisal of the mechanisms underlying the synergistic effects of CTX and adoptive immunotherapy, and may provide new insights into the definition of new and more effective strategies with chemotherapy and adoptive immunotherapy for cancer patients.

Treatment of a newly established transgenic model of chronic arthritis with nondepleting anti-CD4 monoclonal antibody.

We established a novel animal model for rheumatoid arthritis (RA) by following backcrossing to DBA/1 of (SWR/J x DBA/1)F1 TCR-beta Tg mice, previously reported to be highly susceptible to collagen-induced arthritis. These mice evolved, upon collagen type II immunization, into a chronic arthritis that histopathologically resembles RA. The availability of such a model prompted us to study the role of CD4+ T cells throughout the evolution of disease. Here, we show that administration of nondepleting anti-CD4 not only prevented the evolution of disease but also treated established arthritis. Moreover, functional analyses of T cells isolated from anti-CD4-treated mice demonstrated that the mechanism of protection is not achieved by suppression of the Th1 population but is mediated by induction of collagen type II-specific T cell anergy. Our study suggests that: 1) CD4+ T cells have a fundamental role both in the induction and in the perpetuation of disease; 2) targeting T cells may be an appropriate therapeutic option; and 3) a suitable and well-balanced anti-CD4 treatment may be a valid approach to the control of RA.

Suckling CD1 mice as an animal model for studies of Legionella pneumophila virulence.

On the assumption that specific host defences are lower in newborn and infant animals, the susceptibility of CD1 suckling mice to Legionella pneumophila was studied with the hypothesis that this model could detect consistent differences in virulence among Legionella isolates from various clinical and environmental sources. Mice 3-14 days old were indeed markedly susceptible to intraperitoneal challenge with fresh clinical isolates, but not to serially subcultured or type collection strains of L. pneumophila. For example, intraperitoneal inoculation of 10(7) cells of a fresh clinical isolate of L. pneumophila (strain Monza 3) caused 60% mortality of suckling mice in 1 day whereas the same number of cells of a culture-attenuated derivative (strain Monza 3p50) caused <10% mortality in >15 days. Lethal infection by the 'virulent' Monza 3 strain was strictly dependent on mouse age (no death was observed in mice >26 days old), required the inoculation of viable cells and was not related to endotoxin production. The 'virulent' L. pneumophila strain was cleared from mouse lungs less rapidly, while adhering to, and being internalised into the peritoneal exudate cells (PEC) of suckling mice to a greater extent, than the avirulent derivative, as shown by immunofluorescence and confocal microscopy. The Monza 3 strain also induced the production by PEC in vivo of 5-to-10 times more tumour necrosis factor-alpha (TNF-alpha) mRNA than the Monza 3p50 strain. Overall, suckling CD1 mice appear to provide a promising, easily handled, highly reproducible and relatively inexpensive animal model for studies of the virulence of L. pneumophila, and possibly, of the role of pro-inflammatory cytokine production in this phenomenon.

Dynamics of proinflammatory cytokine expression in the joints of mice with collagen-induced arthritis (CIA).

This report contains a description of the cellular localization and kinetics of proinflammatory cytokine expression in murine CIA, a model for rheumatoid arthritis. Tissue cryostat sections of undecalcified paws from type II collagen-immunized DBA/1 mice, taken 1-10 days after the onset of clinical arthritis, were examined for the presence of tumour necrosis factor-alpha (TNF-alpha), IL-1beta and IL-6 using an indirect immunoperoxidase technique. In parallel, interferon-gamma (IFN-gamma) production by lymph node cells, stimulated in vitro with type II collagen, was assessed as a marker of T cell activity. The main areas of TNF-alpha, IL-1beta and IL-6 expression were in the synovial lining layer and in tissue contiguous with cartilage and bone (the marginal zone), in particular at sites of pannus formation and joint erosion. There was a progressive increase in the number of TNF-alpha-, IL-1beta- and IL-6-positive cells from day 1 to day 10 of arthritis, during which time IFN-gamma production by CD4+ T cells from draining lymph nodes declined sharply. A further finding of potential significance was that TNF-alpha was consistently detected at day 1 of arthritis, whereas IL- 1beta-positive cells were not found until day 3, suggesting that the expression of TNF-alpha precedes that of IL-1beta.

Suppression of TNF-alpha expression, inhibition of Th1 activity, and amelioration of collagen-induced arthritis by rolipram.

Rolipram is a type IV phosphodiesterase inhibitor that suppresses inflammation and TNF-alpha production. As anti-TNF-alpha therapy is effective in rheumatoid arthritis, we investigated the effect of rolipram on collagen-induced arthritis (CIA), a murine model of rheumatoid arthritis. Rolipram was administered after the onset of clinical arthritis at doses of 0.5, 3, 5, or 10 mg/kg twice daily, with a dose-dependent therapeutic effect on clinical severity and joint erosion. Immunohistochemical analysis of joints of rolipram-treated mice revealed 67% reduction in TNF-alpha-expressing cells compared with control arthritic mice. In vitro studies using bone marrow-derived macrophages confirmed that rolipram directly suppressed TNF-alpha and IL-12 production following stimulation with IFN-gamma and LPS. The effect of rolipram on T cell activity was studied by measuring Th1/Th2 cytokine production by collagen-stimulated draining lymph node cells from arthritic mice treated in vivo with rolipram. Rolipram reduced IFN-gamma production and increased IL-10, indicating that rolipram down-regulated the ongoing Th1 response to type II collagen. Finally, the effect on CIA of combination therapy was studied using rolipram plus either anti-TNF-alpha or anti-CD4 mAbs. Rolipram plus anti-TNF-alpha was not therapeutically additive, whereas rolipram plus anti-CD4 mAb was clearly additive. This result indicates that the therapeutic effects of rolipram overlap with TNF-alpha blockade, but are complementary to anti-CD4 treatment. It is therefore proposed that a major mechanism of action of rolipram in CIA is suppression of TNF-alpha activity. These findings suggest that type IV phosphodiesterase inhibitors may be effective in pathologic conditions, such as RA, with overexpression of TNF-alpha.

Relationship between Th1/Th2 cytokine patterns and the arthritogenic response in collagen-induced arthritis.

It is hypothesized that the balance of cytokines produced by Th1/Th2 subsets of T helper cells plays an important role in the development of autoimmune diseases. Murine collagen-induced arthritis (CIA) is an example of an autoimmune disease in which immunization with cartilage-derived type II collagen induces, firstly, a T cell response to type II collagen and, secondly, the manifestation of a destructive inflammatory response in affected joints. We have investigated the role of Th1/Th2 responses in the development of CIA by monitoring levels of interferon (IFN)-gamma (a Th1 cytokine) and interleukin (IL)-4 and IL-10 (Th2 cytokines), and IL-1 beta and tumor necrosis factor (TNF) (pro-inflammatory cytokines) produced by cultured draining lymph node cells (LNC) from collagen-immunized DBA/1 mice during the induction phase of arthritis and throughout the time of clinical manifestation and subsequent remission of the disease. Although a transient increase in IL-10 was detected 3 days after immunization, Th2 cytokine production was found to be almost completely suppressed 6 days after immunization. In contrast, IFN-gamma was detected in LNC cultures as early as 6 days after immunization and the addition of type II collagen to the culture medium resulted in an approximately 10-fold increase in IFN-gamma production, indicating that a predominantly Th1 response had become established by this time. IFN-gamma production by LNC was found to be further increased at the time of clinical manifestation of arthritis and could be up-regulated by co-culture with type II collagen. IL-10 was not detected in LNC cultures at the onset of arthritis and IL-4, although present, was found to be markedly suppressed in LNC cultures containing type II collagen. These findings indicate that Th1 responses are predominant at the time of onset of arthritis and that the activation of collagen-specific Th1 cells may result in suppression of Th2 activity. IFN-gamma production declined progressively during the progression and subsequent remission of arthritis whereas levels of IL-10 increased and low, though persistent, levels of IL-4 were detected throughout this period. High levels of IL-1 beta and TNF-alpha production were detected at the onset of the disease. The role of Th1 responses in the development of CIA was further emphasized by the observation that immunization of mice with type II collagen in incomplete Freund's adjuvant, which normally fails to induce arthritis, resulted in a predominantly Th2 cytokine profile.