RESUMO
Inorganic pyrophosphate is identified as the major product of photophosphorylation by isolated chromatophores from Rhodospirillum rubrum in the absence of added nucleotides.
Assuntos
Cromatóforos Bacterianos/metabolismo , Difosfatos/biossíntese , Rhodospirillum/metabolismo , Cromatografia por Troca IônicaRESUMO
Neopterin and beta 2-microglobulin (beta 2-M) concentrations in cerebrospinal fluid (CSF) and blood were measured in 56 individuals in various stages of HIV-1 infection. Elevated levels of neopterin as well as beta 2-M were found in the CSF of three patients with primary HIV-1 infection and also in subjects in the early stages of chronic HIV-1 infection, with the highest levels in HIV-1 isolation-positive people. There was a clear correlation between the concentrations of the two substances and the levels seemed to increase in parallel with progress of infection. A similar pattern was found in blood. Higher concentrations of neopterin and beta 2-M in CSF than in blood were found in patients with advanced dementia in particular. These findings indicate that the cellular immune system in the central nervous system (CNS) may be activated during the early stages of HIV-1 infection without concomitant overt neurological symptoms. The pathological processes in CNS and blood seem to develop in parallel rather than being restricted to one compartment.
Assuntos
Síndrome da Imunodeficiência Adquirida/líquido cefalorraquidiano , Biopterinas/análogos & derivados , HIV-1 , Microglobulina beta-2/líquido cefalorraquidiano , Síndrome da Imunodeficiência Adquirida/sangue , Síndrome da Imunodeficiência Adquirida/complicações , Adulto , Idoso , Biopterinas/sangue , Biopterinas/líquido cefalorraquidiano , Demência/sangue , Demência/líquido cefalorraquidiano , Demência/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neopterina , Microglobulina beta-2/análiseRESUMO
Homosexual men with symptomatic primary HIV-1 infection displayed a pronounced lymphopaenia with significantly depressed numbers of CD3+, CD4+ and CD8+ cells and B cells during the first week of illness. Subsequently, the CD8+ cell counts rose in parallel with numbers of CD3+ cells, atypical lymphocytes and activated (CD38+ and HLA-Dr+) cells to attain maximal levels about a month following onset of illness. In contrast CD4+ and B cell numbers remained low for an extended period of time. Early signs of a host response included a transient appearance of interferon-alpha in the blood and raised levels of neopterin and beta 2-microglobulin (beta 2-M). Neither CD4+/CD8+ cell ratio nor beta 2-M resumed completely normal values during a follow-up period of 2 years. These findings shed some light on pathogenetic events during early HIV-1 infection and suggest that the infection, following the acute symptomatic stage, usually enters a stage of chronic active rather than latent infection.
Assuntos
Infecções por HIV/imunologia , Linfócitos T/imunologia , Adulto , Linfócitos B/imunologia , Biopterinas/análogos & derivados , Biopterinas/sangue , HIV-1 , Homossexualidade , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Interferon Tipo I/sangue , Contagem de Leucócitos , Ativação Linfocitária , Masculino , Neopterina , Subpopulações de Linfócitos T , Microglobulina beta-2/análiseRESUMO
A knee-joint exudate culture yielded on two occasions a gram-negative bacterium. Regular methods for speciation did not provide an identification. The infection was successfully treated with ciprofloxacin. The unknown isolate, CCUG 36768, was subjected to further investigation, including 16S rDNA sequencing, protein profiling, cellular fatty acid analysis, and various biochemical tests, in order to produce a species identification. The 1469 bp-long 16S rDNA sequence did not reveal identity with any known species sequence. CCUG 36768 clustered in a group of species, including Alcaligenes defragrans, Denitrobacter permanens, Taylorella equigenitalis, Alcaligenes faecalis, and four strains of Alcaligenes species without a specific species name. Bordetella species also showed a high degree of similarity with CCUG 36768. Protein profiling, cellular fatty acid analysis and computer-assisted analysis of biochemical profiles indicated similarity with Bordetella-Alcaligenes species, often close to B. holmesii and B. avium. API 20 NE indicated the profile of Moraxella species of poor identity. It is concluded that CCUG 36768 represents a new bacterial species of pathogenic potential in humans. It is related to the Bordetella-Alcaligenes group. Powerful new methods for speciation are available and it is recommended that unknown isolates from normally sterile sites be submitted for further analysis. Several isolates are required for the definition of new species.
Assuntos
Artrite Infecciosa/microbiologia , Bacilos e Cocos Aeróbios Gram-Negativos/classificação , Infecções por Bactérias Gram-Negativas/microbiologia , Articulação do Joelho/microbiologia , Alcaligenes/química , Alcaligenes/classificação , Alcaligenes/genética , Proteínas de Bactérias/análise , Sequência de Bases , Bordetella/química , Bordetella/classificação , Bordetella/genética , Infecções por Bordetella/microbiologia , DNA Bacteriano/análise , DNA Ribossômico/análise , Ácidos Graxos/análise , Bacilos e Cocos Aeróbios Gram-Negativos/química , Bacilos e Cocos Aeróbios Gram-Negativos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/análiseRESUMO
Previous studies have shown that the PWM driven immunoglobulin (Ig) secretion by blood lymphocytes in vitro is reduced shortly after local radiation therapy for breast cancer. In this investigation we have examined the long-term effects of radiation therapy (45 Gy) on this lymphocyte function. A total of 111 disease-free patients treated for operable breast cancer 5-6 and 10-11 years earlier were examined. The Ig classes studied were IgM, IgA and IgG. All patients belonged to a clinical trial where the effect of pre- or post-operative local radiation therapy was evaluated against surgery only. Significant reductions of the amount of spontaneously released IgM in vitro were observed among irradiated patients as compared to the unirradiated 5-6 and 10-11 years after treatment. Such a difference was not observed for IgA and IgG. The PWM induced Ig secretions did not differ significantly between the three patient groups. The long standing reduction of the spontaneous release of IgM by blood lymphocytes in vitro probably lacks clinical significance since the serum levels of this Ig class, as well as IgA and IgG, were similar in irradiated and unirradiated patients.
Assuntos
Neoplasias da Mama/radioterapia , Imunoglobulinas/imunologia , Linfócitos/imunologia , Radioterapia/efeitos adversos , Idoso , Neoplasias da Mama/imunologia , Ensaios Clínicos como Assunto , Feminino , Humanos , Terapia de Imunossupressão , Ativação Linfocitária/efeitos dos fármacos , Pessoa de Meia-Idade , Mitógenos de Phytolacca americana/farmacologia , Distribuição Aleatória , Fatores de TempoRESUMO
The objective of this investigation was to examine further the influence of postoperative adjuvant treatment with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) on the immune system in breast cancer patients and to explore whether such changes are related to prognosis. The 12 CMF courses which were given for a period of 1 year resulted in a progressive lymphopenia. The relative spontaneous secretions of IgA and IgG in vitro increased 4- and 2-fold respectively after the first 3 courses, whereas IgM secretion was unaffected. IgA and IgG secretions in PWM stimulated cultures were not changed, whereas there was a sharp decrease of IgM. The CMF-induced changes of Ig-secretions were similar in patients who developed recurrent disease during a 4-6 year follow-up (n = 11) and those who remained clinically disease-free (n = 14). The results are discussed in relation to the immunopotentiation which may occur following treatment with relatively low doses of chemotherapeutic agents.
Assuntos
Formação de Anticorpos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/imunologia , Ativação Linfocitária , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Ciclofosfamida/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Seguimentos , Humanos , Imunoglobulina A/análise , Imunoglobulina G/análise , Imunoglobulina M/análise , Mastectomia Radical Modificada , Metotrexato/administração & dosagem , Mitógenos de Phytolacca americana , PrognósticoRESUMO
The capacity of PWM (poke-weed mitogen) to stimulate Ig-secretion by blood lymphocytes was examined before and at various times after local radiation therapy (46.0 Gy) for breast cancer. It was observed that the secretion of IgM, IgA and IgG were significantly reduced at completion of radiation therapy. Secretion of IgM was reduced to the highest relative extent (approximately 10% of the pretreatment value). Thereafter there was a recovery of the Ig-secreting capacity which, however, remained below the pretreatment level, 12-18 months after completion of radiation therapy. The capacity of PWM-stimulated blood lymphocytes to secrete specific antibodies against morbilli and herpes simplex virus was also significantly impaired after radiation therapy. The reduction of Ig-synthesis in vitro was not correlated with the increase in the ratio between numbers of monocytes and lymphocytes in peripheral blood after radiation therapy. Possible explanations for these results are discussed.
Assuntos
Linfócitos B/efeitos da radiação , Neoplasias da Mama/radioterapia , Imunoglobulinas/metabolismo , Adulto , Idoso , Anticorpos Antivirais/análise , Linfócitos B/imunologia , Neoplasias da Mama/imunologia , Feminino , Humanos , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Imunoglobulina M/metabolismo , Pessoa de Meia-Idade , Monócitos/efeitos da radiação , Mitógenos de Phytolacca americana/farmacologia , Fatores de TempoRESUMO
Bestatin, an immunostimulating substance of microbial origin, was examined for its capacity to augment immune responses of blood lymphocytes in bladder cancer patients having received a full course of local irradiation (64 Gy). Following irradiation the patients became lymphopenic and the lymphocytes exhibited impaired mitogenic responses to phytohemagglutinin (PHA) and purified protein derivative of tuberculin (PPD) and reduced poke weed mitogen induced secretion of immunoglobulins in vitro. Patients who were randomized to receive daily oral Bestatin treatment exhibited enhanced recoveries of PHA- and PPD-responses and enhanced recovery of the IgM secreting capacity compared to irradiated patients who did not receive Bestatin. Repopulation of the blood lymphocyte population, however, was not enhanced by Bestatin treatment. It is concluded that Bestatin treatment may enhance the recovery of radiation induced functional defects of the immune system in cancer patients.
Assuntos
Adjuvantes Imunológicos/uso terapêutico , Leucina/análogos & derivados , Linfócitos/efeitos dos fármacos , Neoplasias da Bexiga Urinária/terapia , Terapia Combinada , Humanos , Imunoglobulinas/metabolismo , Técnicas In Vitro , Leucina/uso terapêutico , Contagem de Leucócitos , Ativação Linfocitária/efeitos dos fármacos , Linfócitos/efeitos da radiação , Estudos Prospectivos , Distribuição Aleatória , Neoplasias da Bexiga Urinária/imunologia , Neoplasias da Bexiga Urinária/radioterapiaRESUMO
Radiation treatment of breast cancer patients (45.0 Gy) profoundly affected the peripheral blood lymphocytes. The number of these cells was markedly reduced with non-T-cells being more extensively depleted than T-cells immediately after radiation. The long-lasting lymphopenia, on the other hand, was mainly due to reduced number of T-cells. Antigen and mitogen stimulability, MLC reactivity, pokeweed (PWM)-induced immunoglobulin (Ig) production in vitro, and different cytotoxic functions decreased. Depletion of lymphocytes largely restored the radiation-depressed lymphocyte reactivity. The effects of in vitro exposure of blood lymphocytes to x-rays were similar to those seen after radiotherapy. Non-T-cells and T-cells with Fc-receptors for IgG were relatively radiosensitive. This latter observation agreed well with demonstrated increase of PWM-induced Ig synthesis after in vitro exposure to x-rays. T-suppressor cells defined by monoclonal antibodies were, however, radioresistant. The cytotoxic functions were reduced. No correlations were found between the pretreatment immunological status or the extent of radiation-induced immunological suppression, respectively, and prognosis.
Assuntos
Neoplasias Ovarianas/radioterapia , Linfócitos T/efeitos da radiação , Adulto , Idoso , Citotoxicidade Celular Dependente de Anticorpos/efeitos da radiação , Divisão Celular/efeitos dos fármacos , Feminino , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Células Matadoras Naturais/efeitos da radiação , Contagem de Leucócitos , Pessoa de Meia-Idade , Mitógenos/farmacologia , Monócitos , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/cirurgia , Prognóstico , Receptores Imunológicos , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/efeitos da radiaçãoRESUMO
Guinea pigs immunized with mycelium from Trichophyton mentagrophytes in Freund's complete adjuvant were tested intradermally with the following trichophytin preparations: TrI extracted by ethylene glycol, TrII extracted by phenol and TrII, a commercially obtained preparation fromSächsisches Serumverk KG. In our experience, TrI was found to be superior to the other preparations. It showed signifiicant delayed skin reactions in all sensitized animals and none in the controls. Lymphocyte stimulation test with this preparation (TrI) gave positive results.
Assuntos
Hipersensibilidade Tardia , Tricofitina , Animais , Cobaias , Ativação Linfocitária , Masculino , Testes CutâneosRESUMO
The helper effect of T cells on B-cell immunoglobulin (Ig) responses induced by pokeweed mitogen (PWM) or purified protein derivative of tuberculin (PPD) was studied in lymphocytes from synovial fluid (SF) and blood of nine patients with rheumatoid arthritis (RA) and eight patients with other forms of chronic arthritis. In PWM cultures the helper effect of SF T cells on Ig responses (IgG, IgM, IgA) of autologous and allogeneic blood B cells was lower than that of blood T cells (P less than 0.01). This decrease was more pronounced in patients with RA than in patients with non-RA. In PPD cultures no significant difference was found between the helper effect of SF T cells and blood T cells on the Ig responses of allogeneic blood B cells or on the IgG response of autologous blood B cells, whereas the helper effect of SF T cells on the IgM and IgA responses of autologous blood B cells was decreased. The Ig responses to PWM or PPD in cocultures of autologous blood B and T cells were not significantly different between patients and healthy controls. The PWM- and PPD-induced Ig responses of SF B cells were lower than those of blood B cells when cocultured with autologous blood T cells. SF B cells produced IgG but usually little IgM and IgA. Thus there was a dysfunction of SF B cells and of SF T cells in a PWM-driven system, but a fairly good helper function of SF T cells in a PPD-driven system.
Assuntos
Artrite Reumatoide/imunologia , Artrite/imunologia , Linfócitos B/imunologia , Membrana Sinovial/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Doença Crônica , Feminino , Humanos , Imunoglobulinas/análise , Masculino , Pessoa de Meia-Idade , Mitógenos de Phytolacca americana/farmacologia , Linfócitos T/classificação , Tuberculina/farmacologiaRESUMO
The suppressor effect of synovial fluid (SF) T8 cells and blood T8 cells on the pokeweed mitogen (PWM)-induced T4 cell-dependent immunoglobulin production of autologous blood B cells was studied in nine patients with chronic rheumatic diseases (six patients with rheumatoid arthritis (RA), one patient with juvenile RA, and two patients with other forms of chronic arthritis). The suppressor effect of SF T8 cells was of the same magnitude as that of equal numbers of blood T8 cells from patients and healthy controls. However, the relative number of T8 cells was higher among SF T cells than among blood T cells in several cases. Good synovial T8 cell suppression was also demonstrated in coculture experiments where SF T4 cells and B cells were used. In PPD (purified protein derivative of tuberculin)-stimulated cultures the suppressor effect of SF T8 cells as well as of blood T8 cells from patients and controls was lower than it was in PWM-stimulated cultures. In most patients SF T4 cells showed a much better PWM-induced helper function than did non-fractionated SF T cells. Thus the poor PWM induced helper effect of non fractionated synovial T cells was in some cases mainly due to the suppressor effect of T8 cells, whereas in some cases there was also a deficient helper function of synovial T4 cells.
Assuntos
Artrite Reumatoide/imunologia , Artrite/imunologia , Membrana Sinovial/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Linfócitos B/imunologia , Doença Crônica , Feminino , Humanos , Imunoglobulinas/biossíntese , Masculino , Pessoa de Meia-Idade , Mitógenos de Phytolacca americana/farmacologia , Linfócitos T/classificação , Tuberculina/farmacologiaRESUMO
The suppressor effect of T8 cells on antigen-induced, as compared to pokeweed mitogen-induced, T4 cell dependent immunoglobulin (Ig) production by B cells of healthy subjects was studied. The antigens used were purified protein derivative of tuberculin (PPD) and tetanus toxoid (TT). The suppressor effect of T8 cells on IgG, IgM and IgA responses in co-cultures of T4 cells and B cells was significantly stronger in the pokeweed mitogen driven system than in PPD- and TT-driven cultures under the same experimental conditions.
Assuntos
Tolerância Imunológica , Imunoglobulinas/biossíntese , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Linfócitos B/imunologia , Feminino , Humanos , Cooperação Linfocítica , Masculino , Pessoa de Meia-Idade , Mitógenos de Phytolacca americana/farmacologia , Toxoide Tetânico/imunologia , Tuberculina/imunologiaRESUMO
Radiosensitive T cell suppression was studied in relation to the level of T cells with IgG-Fc receptor (TG cells) in synovial fluid and blood of nine patients with rheumatic diseases. Irradiation of T cells significantly decreased the proportion of TG cells in the blood of patients and healthy controls. The proportion of synovial TG cells was low in all patients before as well as after irradiation. Irradiation enhanced the helper effect of T cells on pokeweed-mitogen induced immunoglobulin production by allogeneic B cells. This increased helper effect was taken as an expression of decreased suppressor activity following irradiation. By this method suppressor activity was demonstrable in synovial T cells of six out of nine patients and in blood T cells of six out of eight patients and six out of eight healthy subjects. Thus the low level of synovial TG cells was in most patients not associated with a lack of radiosensitive synovial suppressor cell activity.
Assuntos
Receptores Fc , Receptores Imunológicos , Doenças Reumáticas/imunologia , Linfócitos T/efeitos da radiação , Adulto , Artrite Juvenil/imunologia , Linfócitos B/imunologia , Feminino , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Teste de Cultura Mista de Linfócitos , Masculino , Pessoa de Meia-Idade , Mitógenos de Phytolacca americana/farmacologia , Receptores de IgG , Líquido Sinovial/citologia , Líquido Sinovial/imunologia , Linfócitos T/classificação , Linfócitos T/imunologia , Linfócitos T Reguladores/imunologiaRESUMO
Lymphocyte stimulation tests and determination of T lymphocyte subpopulations were undertaken before and 7-11 days after rubella vaccination of healthy subjects. The proliferatory response of blood mononuclear cells to phytohemagglutinin (PHA) and purified protein derivate was suppressed after vaccination, as was the immunoglobulin production of pokeweed mitogen (PWM) stimulated cultures. After removal of phagocytic cells the response to PHA was still suppressed after vaccination in most cases, but when the cultures were depleted of non-T lymphocytes the suppression was no longer demonstrable. The proportion of T lymphocytes with receptors for the Fc part of IgG increased after vaccination, whereas there was no significant change of the T lymphocyte subpopulations identified with monoclonal antibodies directed at the suppressor/cytotoxic or helper T cell subsets.
Assuntos
Anticorpos Monoclonais/imunologia , Receptores Fc , Rubéola (Sarampo Alemão)/imunologia , Linfócitos T/imunologia , Adolescente , Adulto , DNA/biossíntese , Feminino , Humanos , Ativação Linfocitária , Fito-Hemaglutininas/farmacologia , Mitógenos de Phytolacca americana/farmacologia , Vacina contra Rubéola/imunologia , Linfócitos T/classificação , Linfócitos T Reguladores/imunologia , Tuberculina/imunologiaRESUMO
The kinetics of Borrelia burgdorferi-specific serum IgG antibody values in 74 patients treated for acrodermatitis chronica atrophicans was analysed by means of enzyme-linked immunosorbent assay. At the last clinical control, there had been no clinical signs of active infection. The serological follow-up time ranged from 12 months to 5 1/2 years (median 2 years and 1 month). In 68 (92%) of the 74 patients, a significant decrease of the specific antibody values was found within 3 years after the initiation of therapy. In 53 (72%) of the patients, this decrease was found within 15 months. Most of the patients remained seropositive during the follow-up period. The results show that a significant decline of the levels of serum IgG antibodies to Borrelia burgdorferi can be expected in the majority of patients who do not exhibit clinical evidence of persistent infection after antibiotic treatment of acrodermatitis chronica atrophicans.
Assuntos
Acrodermatite/imunologia , Acrodermatite/microbiologia , Anticorpos Antibacterianos/sangue , Grupo Borrelia Burgdorferi/imunologia , Eritema Migrans Crônico/imunologia , Imunoglobulina G/sangue , Acrodermatite/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Quimioterapia Combinada/uso terapêutico , Ensaio de Imunoadsorção Enzimática , Eritema Migrans Crônico/tratamento farmacológico , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The blood lymphocyte population was studied in 23 breast cancer patients treated with adjuvant tamoxifen for 1.5-2 years, and in an equal number of control patients. The size and cellular composition of the blood lymphocyte population, as assessed by monoclonal antibodies directed against various subsets, did not differ between the two patient groups. However, lymphocytes from the tamoxifen-treated patients exhibited a significantly lower NK activity against K562 cells. In contrast, the proliferative response of lymphocytes to ConA was significantly higher. These results indicate that tamoxifen may modulate the immune system.
Assuntos
Linfócitos/análise , Tamoxifeno/sangue , Idoso , Linhagem Celular , Feminino , Humanos , Células Matadoras Naturais/imunologia , Pessoa de Meia-IdadeRESUMO
For evaluation of its prognostic value, the level of serum beta-2-microglobulin was determined in early serum samples from 88 patients with persistent generalized lymphadenopathy in a prospective longitudinal study. Patients with serum beta-2-microglobulin greater than 2.6 mg/l were found to have a significantly higher risk of developing AIDS earlier when compared to patients with a lower level (p less than 0.001).
Assuntos
Complexo Relacionado com a AIDS/sangue , Síndrome da Imunodeficiência Adquirida/diagnóstico , Microglobulina beta-2/análise , Humanos , Estudos Longitudinais , Prognóstico , Estudos Prospectivos , Fatores de Risco , Fatores de TempoRESUMO
T lymphocyte subpopulations and their in vitro activities were determined in patients with alopecia areata (AA) and alopecia universalis (AU). The frequencies of T cells with receptors for IgG and T cells with receptors for IgM were determined in 16 cases. The IgG and IgM production of B lymphocytes cocultured with autologous and allogeneic T lymphocytes in the presence of PWM was determined in 12 and 9 cases, respectively, and the antibody-dependent cell-mediated cytotoxicity (ADCC) of unfractionated lymphocytes was examined in 6 cases. Patients with AA and AU had a higher proportion of Tg cells and more pronounced ADCC of unfractionated peripheral lymphocytes than normal persons. Furthermore, PWM-induced Ig production of B lymphocytes in the presence of autologous T lymphocytes seemed to be lower than that of controls.
Assuntos
Alopecia em Áreas/imunologia , Linfócitos T/classificação , Adulto , Citotoxicidade Celular Dependente de Anticorpos , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Masculino , Pessoa de Meia-Idade , Neuraminidase/farmacologia , Mitógenos de Phytolacca americana/farmacologia , Formação de Roseta , Linfócitos T/imunologiaRESUMO
T-lymphocyte subpopulations and pokeweed mitogen(PWM)-induced immunoglobulin (Ig) synthesis of mononuclear cells in vitro were studied in patients with psoriasis as well as in age- and sex-matched normal blood donors. The frequences of T cells with receptors for IgG (Tg) and T cells with receptors for IgM (Tm) were examined. The IgG and IgM synthesis in mononuclear cell suspensions in the presence of different amounts of PWM was determined. The percentage of total T cells (rosetting with neuroaminidase-treated sheep red blood cells), including high and low affinity T lymphocytes showed no difference between the patient group and controls. The patients with psoriasis had a significantly higher mean proportion of Tg cells than the normal donors whereas there was no significant difference in the proportions of Tm cells between these two groups. The PWM-induced Ig synthesis in the mononuclear cell suspension seemed lower in patients with psoriasis than in controls, the difference being statistically significant when the results were expressed as ratios of Ig amounts present in the supernatants of PWM-stimulated and non-stimulated cultures (index of stimulation).