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R Vuento

Publications and source records attributed to R Vuento.

30 records · Page 2Linked to original sources
PubMed1987

Association of persisting IgA response with yersinia triggered reactive arthritis: a study on 104 patients.

Twelve to 16 months after Yersinia enterocolitica O:3 enteritis 33 (85%) of the 39 patients who developed reactive arthritis as a postinfection complication had IgA class and 28 (72%) had IgG class anti-yersinia antibodies. In contrast, 7 (32%) of the 22 patients who did not develop arthritis were positive in the IgA test and 11 (50%) positive in the IgG test. The results were about the same when the material was divided into cases with diagnosis of yersiniosis verified by stool culture or by serology. These results confirm the value of enzyme linked immunosorbent assay (ELISA) in the diagnosis of yersiniosis, particularly in cases with postinfection complications when the stool isolations remain negative.

Adult↗
PubMed1985

Pathogenesis of Yersinia-triggered reactive arthritis: immunological, microbiological and clinical aspects.

When a patient develops reactive arthritis after Yersinia enteritis, the following conditions are often fulfilled: the patient is HLA-B27-positive; however, some B27-negative individuals develop severe arthritis and some positives do not, in the initial phase, the diarrhea is milder, the anti-Yersinia antibody response of IgG class is more vigorous and persists longer, the anti-Yersinia antibody response of IgA class is more vigorous and persists much longer, the anti-Yersinia antibodies of IgA1 and IgA2 subclass, those with J-chain and, especially, those with secretory piece are produced more vigorously, indicating local immunostimulation close to the intestinal epithelium, in the early phase, Yersinia-IgM immune complexes are found in the circulation, and the lymphocyte transformation response against not only Yersinia but also against other gram-negative enteric bacteria is weaker. When all these aspects are considered together a strong suspicion arises that the patients who are destined to develop reactive arthritis fail in their first line of defense against the invading organism when contracting a Yersinia enteritis. This may lead to persistence of the microorganism within the body, e.g., in the intestinal epithelium or in the mesenteric lymphoid tissues, maintaining a stimulus for a prolonged--apparently futile and perhaps harmful--antibody production. Finally, the initiating and decisive factor should not be forgotten: the Yersinia. Why and how it triggers the process is at present one of the enigmas of the pathogenesis of reactive arthritis.

Antibodies, Bacterial↗
PubMed1984

Role of Ia-positive cells in the lymphocyte responses to Yersinia.

Activation of T lymphocytes by an antigen requires joint recognition of the antigen and the class-II HLA determinants on the membrane of the antigen-presenting cells (APC). Patients with reactive arthritis exhibit a depressed lymphocyte transformation response to Yersinia, suggesting a possible immunoregulatory disturbance in these patients. In this study the role of Ia (class-II HLA antigen)-positive APC in the lymphocyte response to a complex antigen, whole Yersinia bacterium, was evaluated. The results demonstrate that Ia-positive cells are necessary for the T-lymphocyte response to Yersinia. The role of APC in the pathogenesis of reactive arthritis is discussed.

Antibodies, Monoclonal↗
PubMed1984

IgM, IgG, and IgA synthesis in vitro in persons suffering from yersinia arthritis and in patients with ankylosing spondylitis.

In ankylosing spondylitis (AS) and in yersinia arthritis the main findings in serum immunoglobulin (Ig) studies have been raised IgA in AS and a high anti-yersinia IgA and IgG response and the persistence of IgA class antibodies in yersinia arthritis. In order to study predisposition to high IgA response in AS and yersinia arthritis we measured the in-vitro Ig production in patients with AS and in persons who have once had yersinia arthritis, and we compared it with the Ig production in persons who have had yersiniosis but recovered without getting arthritis and with that in healthy controls. IgA secretion by peripheral blood lymphocytes stimulated by pokeweed mitogen was the same in all 4 groups, and no signs of higher IgA production in AS patients could be found. In AS patients lymphocyte activation by whole yersinia bacteria resulted in higher total IgG production than in healthy controls. The total number of plaque-forming cells in yersinia-stimulated cultures was significantly higher in persons who have had yersiniosis without arthritis than in persons who have suffered from yersinia arthritis or in persons in other groups. AS patients had low IgM production, which reverted to normal when hydrocortisone was added to the culture. The in-vitro Ig production in general did not correlate with the presence of the HLA B27 antigen but rather with the clinical history of the subjects studied.

Adult↗
PubMed1984

Lymphocyte transformation responses to gram negative bacteria after Yersinia and Salmonella infection: the importance of enterobacterial common antigen for the response.

Increased lymphocyte transformation (LT) responses have been observed in Yersinia infections both against the causative bacterium and against other enterobacteria. The responses of patients with reactive arthritis are lower than those of non-arthritic patients. We have now studied the LT responses against several gram negative bacteria and against a pair of enterobacterial common antigen (ECA) positive and ECA negative Salmonella typhimurium strains in patients after Yersinia or Salmonella infection. The haptenic ECA alone seemed not to be responsible for the increased LT responses. We conclude that some other common antigenic determinants present on the bacteria are responsible for the LT response.

Antigens, Bacterial↗
PubMed1983

Increased immunoglobulin production in vitro in healthy HLA-B8-positive persons.

The histocompatibility antigens B8 and DR3 are associated with several autoimmune diseases, and immune hyper-responsiveness has been believed to be one factor in the pathogenesis of these diseases. In the present study we compared the in vitro immunoglobulin production of healthy HLA-B8-positive individuals with that of HLA-B8-negative individuals. In HLA-B8-positive persons a higher number of pokeweed mitogen (PWM)-stimulated Ig-secreting cells was obtained. When the cells were stimulated with PWM in the presence of a physiological concentration of hydrocortisone (HC), the secretion of IgG was significantly higher in HLA-B8-positive individuals. This finding indicates that the PWM-stimulated IgG secretion in healthy HLA-B8-positive individuals is more sensitive for the enhancing action of HC.

Antibody-Producing Cells↗
PubMed1983

Depressed lymphocyte transformation by yersinia and Escherichia coli in yersinia arthritis.

Lymphocyte transformation responses were studied in 21 patients with acute yersinia infection followed-up after the acute infection for up to one year. Eight patients had reactive arthritis caused by yersinia. The responses to the causative serotype of yersinia were significantly lower (p less than 0.05) in patients with arthritis than in those without arthritis. Stimulation with Escherichia coli gave lower responses than with yersinia, but with E. coli the difference between arthritic and nonarthritic groups was more significant (p less than 0.02). The responses to yersinia and E. coli were not correlated with the presence of HLA B27. Lymphocyte transformation by purified protein derivative of tuberculin, streptokinase-streptodornase, phytohaemagglutinin, or concanavalin-A revealed no significant differences between the arthritic and nonarthritic groups. The role of the enterobacterial common antigen in the pathogenesis of reactive arthritis and ankylosing spondylitis is discussed.

Adolescent↗
PubMed1983

Antigen-specific lymphocyte transformation in patients with recent yersiniosis.

Lymphocyte transformation in patients with recent yersiniosis was studied. A micromethod using washed blood cells and Yersinia enterocolitica antigen was employed. The washed blood cells were incubated in the presence of various dilutions of heat-treated whole bacteria; these proved as antigen superior to gentamicin- or formalin-treated bacteria. Patients with recent yersiniosis had a significantly higher response against Yersinia antigen as compared to 20 healthy controls, who had either no response or a low response. No difference could be observed in responses against PPD or streptokinase-streptodornase, or in the mitogen responses between these two groups. A marked cross-reaction was observed between Yersinia and Escherichia coli antigen. The results show that patients with recent yersiniosis develop lymphocyte transformation response against Yersinia. Lymphocyte transformation test can be used in the study of host responses against infecting Yersinia in patients with different clinical pictures of yersiniosis.

Antigens, Bacterial↗
PubMedDate not supplied

Pulse lavage washing in decontamination of allografts improves safety.

We analyzed the bacterial contamination rate of 140 femoral head allografts after rinsing the allografts in different decontamination solutions. Bacterial screening methods and cleansing effect of antibiotics (cefuroxime and rifampicin) and pulse lavage were compared. Swabbing and taking small pieces of bone for culture were the screening methods used. Both methods proved to be quite unreliable. Approximately one-fourth of the results were false negative. Culturing small pieces of bone gave the most accurate and reliable results and, therefore, can be recommended as a bacterial screening method. The use of antibiotics in allograft decontamination is controversial. In prophylactic use antibiotics include risks of allergic reactions and resistant development and our results in the present study show that antibiotics do not improve the decontamination any better than low-pressure pulse lavage with sterile saline solution. Therefore, pulse lavage with sterile saline solution can be recommended for allograft decontamination. Our results demonstrate that it decreases bacterial bioburden as effectively as the antibiotics without persisting the disadvantages.

Bacterial Infections↗
PubMedDate not supplied

In vitro lymphoproliferative response to Yersinia: depressed response in arthritic patients years after Yersinia infection.

The persistence of lymphocyte transformation response to Yersinia was studied three to six years after Yersinia infection in subjects who had or had not suffered from reactive arthritis. In persons who had had arthritis, significantly weaker response to Yersinia was found than in those who had recovered without developing arthritis. The same held true also for the response to Klebsiella. These results support and extend our earlier observations of a depressed lymphocyte transformation response to Yersinia during the course of Yersinia arthritis. This phenomenon may be linked to the individual's susceptibility to arthritic complications after Yersinia infection.

Arthritis, Infectious↗
PubMedDate not supplied

Mutans streptococcal serotypes in children with gastroesophageal reflux disease.

It has been suggested that vomiting acid gastric contents in bulimia might favor oral growth of Streptococcus sobrinus. We studied the colonization of Streptococcus sobrinus (serotypes g and d) and Streptococcus mutans (serotypes c, e and f) in sixteen children, ages five to fifteen years, who had suffered for four to eleven years from gastroesophageal reflux, another condition with recurrent acid regurgitation. Our aim was to find out if the prevalence of Streptococcus sobrinus would be higher also in this patient group. Mutants streptococci were detected in twelve out of sixteen (75 percent) study patients of the saliva samples cultured on MSB agar. For the Mutans streptococci positive children healthy controls were matched by salivary levels of mutans streptococci and age as closely as possible. From each child three to six isolates representing both Streptococcus mutans and Streptococcus sobrinus (n = 103) were serotyped by immunodiffusion method. The distribution of serotypes in the study/control group was: c: 7/10; e: 4/2; f: 0/1; g:3/2; d:0/0. One strain in the study group remained untypable. All patients infected with Streptococcus sobrinus were also infected with Streptococcus mutans. Our results indicate the great similarity in the distribution of ms serotypes in the gastroesophageal reflux children and their healthy controls. The data do not suggest that the acid regurgitation would have an influence on the prevalence of Streptococcus sobrinus.

Adolescent↗