Autologous mixed lymphocyte reaction in man. II. Histamine-induced suppression of the autologous mixed lymphocyte reaction by T-cell subsets defined with monoclonal antibodies

The role of histamine H1 and H4 receptors in allergic inflammation: the search for new antihistamines

Histamine has a key role in allergic inflammatory conditions. The inflammatory responses resulting from the liberation of histamine have long been thought to be mediated by the histamine H1 receptor, and H1-receptor antagonists--commonly known as antihistamines--have been used to treat allergies for many years. However, the importance of histamine in the pathology of conditions such as asthma and chronic pruritus may have been underestimated. Here, we review accumulating evidence suggesting that histamine indeed has roles in inflammation and immune function modulation in such diseases. In particular, the discovery of a fourth histamine receptor (H4) and its expression on numerous immune and inflammatory cells has prompted a re-evaluation of the actions of histamine, suggesting a new potential for H4-receptor antagonists and a possible synergy between H1 and H4-receptor antagonists in targeting various inflammatory conditions.

Cutaneous pseudolymphomas

Cutaneous pseudolymphoma refers to a heterogeneous group of benign reactive T- or B-cell lymphoproliferative processes of diverse causes that simulate cutaneous lymphomas clinically and/or histologically. The inflammatory infiltrate is bandlike, nodular, or diffuse and is composed predominantly of lymphocytes with or without other inflammatory cells. Depending on the predominant cell type in the infiltrate, cutaneous pseudolymphomas are divided into T- and B-cell pseudolymphomas. Cutaneous T-cell pseudolymphomas include idiopathic cutaneous T-cell pseudolymphoma, lymphomatoid drug reactions, lymphomatoid contact dermatitis, persistent nodular arthropod-bite reactions, nodular scabies, actinic reticuloid, and lymphomatoid papulosis. Cutaneous B-cell pseudolymphomas include idiopathic lymphocytoma cutis, borrelial lymphocytoma cutis, tattoo-induced lymphocytoma cutis, post-zoster scar lymphocytoma cutis, and some persistent nodular arthropod-bite reactions. This review attempts to discuss current aspects of the classification, pathogenesis, clinical spectrum, histopathologic and immunohistochemical diagnosis, and laboratory investigations for clonality in the various types of cutaneous pseudolymphomas.

Esophageal candidiasis as a complication of inhaled corticosteroids

BACKGROUND

Oropharyngeal candidiasis is a well-described side effect of inhaled corticosteroids. Nevertheless, few cases of esophageal candidiasis have been reported.

OBJECTIVE

To present a patient with esophageal candidiasis associated with inhaled corticosteroids.

METHODS

Case report.

RESULTS

Our patient is a 70-year-old white woman with a 20-year history of intrinsic asthma, well controlled on triamcinolone acetonide 400 micrograms, ipratropium bromide 36 micrograms, and pirbuterol acetate 400 micrograms, each inhaled four times daily. She reported no oral steroid use for > 4 years and that she always rinsed her mouth following triamcinolone acetonide inhalation. The patient had gastritis with peptic ulcer disease in the past and developed worsening dyspeptic pain and heartburn. Following discontinuation of cimetidine and initiation of ranitidine without improvement, esophagogastroduodenoscopy was performed. Several small white patches in the mid and distal esophagus could not be removed with pressure. A biopsy confirmed the diagnosis of candidal esophagitis. Following a 4-week course of fluconazole, the patient was clinically improved and follow-up esophagogastroduodenoscopy was normal. There was no evidence of underlying cellular immunosuppression, malignancy, or diabetes mellitus and no history of recent antibiotic usage. Delayed skin tests revealed 5 x 5 mm induration to dermatophytin. Delayed hypersensitivity to Candida and mumps tests was absent. There was strong in vitro lymphocyte transformation and a positive immediate skin test response to Candida. ELISA for human immunodeficiency virus was negative. T and B cell counts were normal with CD4 = 630/mm3, CD8 = 520/mm3, and absolute B cell = 120/mm3. It is possible that this patient's immediate hypersensitivity response to Candida suppressed her delayed response. Candidal esophagitis is a rare, yet important, complication of inhaled corticosteroid use.

CONCLUSION

Immunocompetent patients on inhaled corticosteroids with medically unresponsive symptoms of esophagitis should be investigated for esophageal candidiasis.

Drugs with antihistaminic properties as a cause of atypical cutaneous lymphoid hyperplasia

BACKGROUND

Although an association between antihistaminic drugs and atypical cutaneous lymphoid infiltrates has not been reported previously, in vitro evidence suggests that these agents perturb certain lymphoid functions through binding to histamine receptors, including a novel growth-promoting intracellular histamine receptor, designated HIC.

OBJECTIVE

We studied the clinical findings and histopathologic findings in 14 patients taking antihistaminic drugs in whom atypical cutaneous lymphoid infiltrates developed.

METHODS

We retrospectively reviewed the clinical and histologic features of these patients' skin lesions.

RESULTS

The clinical presentations included solitary or multiple nodules and plaques, and multiple papules. In some patients a temporal association between drug therapy and clinical course was observed, as the lesions improved or resolved after a decrease or discontinuation of the drug. Eleven patients were taking two or more medications that in vitro are associated with alterations in lymphocyte function, including agents without antihistaminic properties. A diagnosis of pseudolymphoma seemed clinically apposite in seven of the 14 patients on the basis of either resolution of the eruption or presentation of a solitary nodule that did not recur after excision. Histologic analysis showed four distinct morphologies: mycosis fungoides-like, nodular dermal infiltrates consistent with either lymphocytoma cutis or lymphoma cutis, lymphomatoid vascular reaction, and follicular mucinosis. Common to cases showing the first pattern were histologic features suggesting a delayed-type hypersensitivity reaction, thus enabling their distinction from mycosis fungoides. The infiltrates were predominantly of T-cell phenotype.

CONCLUSION

Antihistamines are associated with atypical lymphoid hyperplasia in some patients. The antihistaminic drug may not be the provocative agent per se; rather, a drug-induced immunodysregulatory state may render an abnormal immune response to some other exogenous antigen. Multidrug therapy with these and other agents known to exert immunomodulatory effects may increase susceptibility to the development of atypical lymphoid hyperplasia and malignant lymphoma.

The clinical effect of percutaneous histamine on allergic contact dermatitis elicited to fragrance mix

Histamine (2-(4-imidazol)ethylamine) has been shown to downregulate cell-mediated reactions in vitro. However, the rôle of such downregulation in vivo has not yet extensively been studied in humans. In an attempt to gain more insight into this, we studied in vivo the effect of percutaneous histamine on an allergic contact reaction elicited to fragrance mix in 28 human volunteers with previously-known sensitization (patch tests) to this allergen. Histamine (0.1 mg/ml) was administered either via subcutaneous injections or by scratching at the site of patch tests to one concentration (8% pet.) of fragrance mix at different times. Histamine and control solution were administered immediately before patch testing (0 hours) or 2x at 0 and 24 h (after application). No significant differences were observed in the grade of delayed-type hypersensitivity reaction (DTHR) to fragrance mix (8% pet.) by visual reading when histamine or control solution was administered. This study did not exclude the possibility that histamine could inhibit DTHR to lower concentrations of the allergen used, and therefore additional in vivo studies are required.

Abnormal T suppressor cell function in juvenile rheumatoid arthritis

The purpose of this study was to analyze T suppressor cell function in juvenile rheumatoid arthritis (JRA). JRA is a chronic inflammatory childhood disease of unknown etiology that is characterized by arthritis and immunoregulatory abnormalities. T suppressor cell precursors (CD8+, CD28-) were purified from the peripheral blood of 24 JRA patients, using a combination of monoclonal antibodies. These cells were treated with histamine or concanavalin A, agents that are known to induce suppressor activity. They were also tested for their ability to inhibit the proliferative response of autologous T cells to phytohemagglutinin. In some experiments, the accumulation of intracellular cAMP following histamine treatment was also measured. Twelve of 13 patients with clinically active JRA showed abnormal histamine-inducible T suppressor cell function, characterized by the failure of CD8+, CD28- T cells to mediate any detectable suppression. The failure of these cells to accumulate intracellular cAMP after histamine treatment was observed in 5 of 5 patients tested who had active disease. In contrast, 11 of 11 patients with clinically inactive JRA, 5 of 5 patients with cystic fibrosis, and 9 of 9 pediatric control subjects had normal histamine- and concanavalin A-inducible T suppressor cell function, and a normal cAMP response to histamine. These results suggest that patients with clinically active JRA have a reversible defect in T suppressor cell function that is associated with a failure of T suppressor cell precursors to accumulate intracellular cAMP following their exposure to selected immune stimuli.

Histamine blocks interleukin 2 (IL-2) gene expression and regulates IL-2 receptor expression

Histamine inhibited the proliferative response of human peripheral blood mononuclear cells (PBMC) to the T cell mitogen Phytohemagglutinin-P (PHA-P) in a dose-dependent fashion. This inhibition was mediated via the H2 receptor since cimetidine, a known H2 antagonist, removed the inhibition, whereas the addition of the H1 antagonist Diphenhydramine did not. Inhibition occurred during the inductive phase of the cell cycle, since histamine added 24 hours after PHA-P stimulation had no effect on subsequent T cell proliferation, and was attributable to inhibition of interleukin-2 (IL-2) gene expression. Both secreted IL-2 and messenger RNA coding for IL-2 were inhibited by histamine. In contrast, histamine exerted no inhibitory effect on the expression of cell surface receptors for IL-2 as determined by flow cytometry. Furthermore, histamine-treated cells retained full responsiveness to exogenously administered IL-2, which completely reversed the anti-proliferative effect of histamine. In some donors, histamine enhanced the percentage of IL-2 receptor positive cells. Stimulated PBMC from AIDS KS patients as a group, displayed a lower percentage of IL-2 receptor bearing cells, which was significantly increased by the addition of histamine even at concentrations as low as 10(-6) M and peaking at 10(-3) M. These findings indicate that histamine exerts its anti-proliferative effects on T cells by inhibiting IL-2 production, via blockade of IL-2 gene expression. In addition, histamine seems to exert immunomodulating effects on IL-2 receptor expression, particularly in those individuals with AIDS-KS.

Inhibitory effects of histamine on interleukin 2 and gamma interferon production of different human T helper cell subsets

We have previously demonstrated that histamine can inhibit human helper T cells by direct interaction with these cells. It has now been investigated whether histamine inhibits lymphokine production by various subsets of CD4+ human T cells separated with the Leu-8 (p80) and Leu-18 (anti-CD45R;p220) monoclonal antibodies (MoAb). Histamine was shown to suppress to a similar extent the production of interleukin 2 (IL-2) and gamma interferon (IFN-gamma) by Leu 3+, Leu 3+8+, and Leu 3+8- cell subsets. Mitogen-activated, unseparated Leu 3+ and purified Leu 3+8- cells produced maximal amounts of IL-2 after 24 h and IFN-gamma after 72 h of culture. In contrast, the Leu 3+18+ subset produced no IL-2 after 24 h, and maximal amounts of IL-2 no sooner than 48 h of culture, and only small amounts of IFN-gamma during the entire culture period of 96 h. Histamine suppressed the production of IL-2 by both subsets, both when produced early (after 24 h), as in the case of the Leu 3+18- subset, and late (after 48 h of culture), as for the Leu 3+18+ subset. The IFN-gamma production by the Leu 3+ and Leu 3+18- cells and the marginal production by Leu 3+18+ cells were significantly suppressed by histamine. Dual staining with Leu 8 and Leu 18 MoAb demonstrated that the Leu 18- cell compartment included both Leu 8+ and Leu 8- cells. It was shown that the inhibitory effect of histamine on the early production of IL-2 and the major production of IFN-gamma by T helper cells is mediated via action on both the Leu 3+18-8- and the Leu 3+18-8+ cells. The inhibitory effect of histamine on the late production of IL-2 is mediated mainly via action on Leu-18+ cells.

Histamine-induced regulation of IL-2 synthesis in man: characterization of two pathways of inhibition

Histamine at molar concentrations ranging from 10(-5) to 10(-7) exerted an inhibitory effect upon IL-2 synthesis by peripheral blood mononuclear cells in normal man; two pathways of inhibition are described. The first pathway was found to alter the T4 lymphocytes which, in the system used in this study, synthesized nearly 90% of the total IL-2 production and had no suppressive activity. This suggests that histamine can act at the level of IL-2-producing cells. The second pathway of inhibition was related to induction of suppressor cells. Peripheral blood lymphocytes pre-incubated for 1 h with histamine 10(-5)-10(-7) M inhibited the IL-2 synthesis of normal autologous lymphocytes in a co-culture system. This activity was radio-resistant (1200 r) and mediated by T8 lymphocytes. These two pathways of inhibition were mediated by the specific interaction of histamine with H1- and H2-receptor-bearing mononuclear cells.

Mast cell numbers in rheumatoid synovial tissues. Correlations with quantitative measures of lymphocytic infiltration and modulation by antiinflammatory therapy

Synovial biopsy specimens from 20 patients with rheumatoid arthritis were subjected to quantitative analysis for several parameters of inflammation and for enumeration of synovial tissue mast cells. Strong positive correlations were found between numbers of mast cells per cubic millimeter of synovial tissue and the following synovial tissue parameters: inflammatory index (a quantification of lymphocytic infiltration), Leu-3a grade (T helper/inducer lymphocytes), Leu-1 grade (T lymphocyte), and plasma cell grade. A strong negative correlation was found between the synovial mast cell count and the extent of sublining layer fibrin deposition. Correlations between synovial mast cell count and Leu-2a grade, ratio of Leu-3a grade:Leu-2a grade, OKM1 grade, HLA-DR grade, and lining layer thickness grade did not reach statistical significance. In addition, we obtained synovial specimens from 6 of the patients both before and after long-term therapy with oral methotrexate and from 3 of the patients before, and 1 week after, an intraarticular injection of steroid. The 3 patients who had an intraarticular steroid injection showed a 67-96% decrease in the number of synovial tissue mast cells; there was no significant change in the number of synovial mast cells in the tissues of the 6 patients who received oral methotrexate. These observations are the first documentation of a quantitative relationship between the number of mast cells and the number and phenotypic profile of infiltrating lymphocytes in an inflamed tissue, which in this case, is human synovium. Our findings suggest that mast cells are involved in the pathologic interactions in rheumatoid arthritis and might play a role in the early phases of exacerbations of disease activity.

Distinct histamine-induced cyclic AMP synthesis in acute leukemia

Histamine receptors of the H2 type are found on mature hemopoetic cells such as lymphocytes and monocytes. Since little is known about histamine receptors on immature cells, we studied histamine-induced cAMP synthesis in leukemic cells of 51 patients using 73 samples of peripheral blood and/or bone marrow. Histamine-induced cAMP synthesis was found in all cALL (FAB L1, L2), but only occasionally in AML. In 1 out of 11 myelomonocytic leukemias (M4), and also in 2 out of 5 monocytic leukemias (FAB M5), histamine-inducible cAMP synthesis was found, but no induction of cAMP synthesis by histamine was found in 19 cases from the remaining subgroups (FAB M1-M3, M6). The inhibiting action of H2 antagonists on cAMP synthesis indicates that the receptor is of the H2 type. Since H2 receptors were found in all cALL blasts, we assume a compulsory expression of this receptor on immature cells of the B-lymphocytic lineage.

A human T-T-cell hybridoma-derived lymphocyte chemoattractant factor

Human T-T hybridomas were developed as a strategy for obtaining lymphokines that alter T-lymphocyte motility. Mitogen-stimulated human T lymphocytes were fused with cells of the human CEM lymphoma line and the supernatants derived from these fusion products were assessed for chemoattractant activity in a modified Boyden chamber assay. Supernatants from hybridoma 41B2 enhanced lymphocyte migration to 198 +/- 13% (mean +/- SEM) of control. Characterization by Sephadex G-100 molecular sieve chromatography revealed a single peak of chemoattractant activity corresponding to a molecular weight (MW) of 56,000. This activity eluted from a Sephadex QAE anion-exchange column at 4-6 mS. Subsequent isoelectric focusing in sucrose revealed an isoelectric point of 9.0-9.2. Fractions with activity after sequential molecular sieve and anion-exchange chromatography were concentrated, radiolabeled with 125I, and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography revealed a band which corresponded to a MW of 14,000 (representing four similar monomeric chains) and to the region from which chemoattractant activity could be detected in eluates from slices of unstained gels run in parallel. The biological activity of this hybridoma-derived lymphocyte chemoattractant was abolished by treatment with trypsin and neuraminidase but was unaffected by heating to 56 degrees C. We conclude that certain human T-T-cell hybridomas constitutively elaborate a lymphocyte chemoattractant that appears to be physicochemically identical to a previously described human lymphokine, lymphocyte chemoattractant factor.

Chronic lung disease in children referred to a teaching hospital

Etiology, symptomatology, and host factors were studied in 184 children referred to a teaching hospital for evaluation in an attempt to classify chronic or potentially chronic lung disease. A standardized historical questionnaire, physical findings, chest radiographs, and a laboratory panel identified a diagnosis that could be related directly or indirectly to chronic lung disease in 22% of the subjects. Among the remaining 78%, bronchiectasis was found in 9%, chronic pneumonia in 9%, chronic diseases with wheezing in 56%, and no significant lower respiratory disease in 4%. Analysis of cases with no apparent etiology revealed that the majority of patients had historical evidence of wheezing; often this previously had not been appreciated. Laboratory tests, such as eosinophil count and immunoglobulin E (IgE) testing, did not differentiate between wheezing and nonwheezing patients. Spirometric evaluation was limited because most subjects were younger than 5 years old. For the same reason, testing for bronchial hyperreactivity was not done. This study reemphasizes that wheezing is a major symptom of chronic lung disease in childhood and provides an outline for its evaluation. Although clinical airways reactivity, as exemplified by wheezing, proved to be the most prominent host defect found in this study, its nature, genetic or otherwise, remains to be defined.

Histamine modulates the production of interferon-gamma and interleukin-2 by mitogen-activated human mononuclear blood cells

Histamine inhibited the production of interferon-gamma and interleukin 2 (IL-2) induced in human peripheral blood mononuclear cells by Staphylococcal Enterotoxin A (SEA) but had no effect on the expression of IL-2 receptors. The effects on lymphokine production were dose dependent with maximal inhibition occurring at histamine concentrations of 10(-4) to 10(-6) M. The H2-agonist 4-methylhistamine but not the H1-agonist 2-methylhistamine modulated lymphokine production in a similar manner as histamine. Histamine at concentrations of 10(-3) to 10(-8) M had no inhibitory effect directly on the activity of admixed IL-2 containing medium. The inhibitory effects of histamine could be reversed by the H2-antagonist cimetidine but not by the H1-antagonist diphenhydramine. This indicates that the inhibitory effects of histamine on lymphokine production are mediated through H2-receptors on mononuclear cells.

Importance of coordinated immune stimulation in experimental antitumor treatment

We have proposed an antitumor therapeutic model in mice grafted with Crocker 180TG cells. The treatment strategy involves a coordinated immune stimulation which should always precede treatment of target cells. Potent stimulators mobilizing the majority of immune competent cells can be injected only once since repetition results in adverse effects on the response. Thus, to circumvent this difficulty, we propose the amplification, after a single shot of Corynebacterium parvum extract, of the immune response by cimetidine. Indeed, it has been reported that cimetidine inhibits suppressor T cell functions. The second phase acting on the target employs interferon and arginine butyrate since they reconvert a number of transformed target cells to normal phenotype. Important antitumor effects can be obtained in the present model even if the treatment is initiated relatively late after tumor graft. All the drugs employed are harmless on normal cells and are used at relatively low concentrations.

Metastatic malignant melanoma: regression induced by combined treatment with interferon [HuIFN-alpha(Le)] and cimetidine

With the aim of potentiating the anti-tumour effect of interferon in metastatic malignant melanoma by concomitant inhibition of suppressor T cells, oral cimetidine (histamine-2 receptor antagonist) medication was added to interferon (HuIFN-alpha(Le] therapy in a series of 20 patients. While no objective tumour responses were recorded with interferon treatment alone administered intramuscularly or intratumorally, six patients had objective tumour regressions on subsequent combined therapy. Five out of eight patients with metastases confined to skin and subcutaneous tissue had complete tumour regressions while one patient with skin and lung metastases achieved an extensive partial regression of the skin tumour and a complete roentgenological regression of the lung metastasis. Three additional patients attained a stable disease status for prolonged periods of time. Histopathological examinations confirmed disappearance and/or degeneration of melanoma cells and demonstrated a marked lymphocyte infiltration in tumour sites of the patients with objective tumour regression.

Coordinated therapeutic effects of immune modulators and interferon

Immune modulators injected 24 h before encephalomyocarditis virus significantly increase antiviral resistance in mice when interferon is administered 1 h after the virus. These immune modulators can be crude bacterial extracts or synthetic drugs. In some cases, the responses are additive; in others, they are clearly cooperative. To protect the mice against the development of 180 TG Crocker sarcomas, the association of bacterial extracts and interferon is highly effective under the condition that the drug concentrations and chronological order and number of injections are well defined. In contrast, the conjunction of interferon and synthetic immune modulators, in particular cimetidine, result in delayed tumor development with no significant change in the final survival rate in the experimental model described here.

Effect of histamine and histamine antagonists on natural and antibody-dependent cellular cytotoxicity of human lymphocytes in vitro

The in vitro effect of histamine and its antagonists, cimetidine and clemastine fumarate, on natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) activities of human lymphocytes was investigated. The histamine 1 (H1) antagonist, clemastine fumarate, and the histamine 2 (H2) antagonist, cimetidine, but not histamine alone, inhibited the NK and ADCC activities of lymphocytes when added directly to the mixture of effector and target cells in a 51Cr-release assay. This inhibition was proportional to the concentration of drugs added and was observed at various effector to target ratios against several targets. H1 and H2 antagonists also inhibited NK activities of T cells as well as Percoll-separated, NK-enriched effector cells. The inhibition was significantly reversed by histamine. In target binding assays, clemastine fumarate and cimetidine also decreased the target binding capacity of effector lymphocytes. Further, PBL precultured with histamine (10(-3)-10(-4) M) for 24 hr showed a significant decrease in their NK and ADCC activities. In coculture experiments, PBL precultured with histamine suppressed the NK activity of normal autologous effector lymphocytes. PBL precultured with histamine showed an increased number of OKT8+ cells, as estimated using monoclonal antibodies. The suppression of cytotoxicity was not due to either direct toxicity, steric hindrance, crowding, or cell death, but by functionally viable suppressor cells. An immunoregulatory role for histamine in NK and ADCC reactions is proposed.

Autologous mixed lymphocyte reaction in health and disease states in man

In this review are discussed the nature of T cell subsets, defined with monoclonal antibodies, responding in T-non-T and T-T autologous mixed-lymphocyte reactions (AMLR) and antigens stimulating in AMLR, soluble products of AMLR and generation of suppressor, helper and cytotoxic functions. On the basis of these data a model of immunoregulation in vivo can be proposed. We believe that AMLR is a real-phenomenon and not an artefact and perhaps represents a mechanism by which various immune functions are regulated, including feedback regulation of AMLR. The significance of AMLR is further supported by studies in various human and animal diseases.

Physiochemical characterization of human histamine-induced suppressor factor

A product of histamine-stimulated human lymphocytes, histamine-induced suppressor factor or HSF, was characterized by enzyme treatment, sensitivity to reduction and alkylation, by molecular sieve chromatography, and by polyacrylamide gel electrophoresis. HSF was found to have a wide pH stability (pH 3-10), sensitivity to temperatures greater than 80 degrees C, and to have the properties of a glycoprotein by virtue of its sensitivity to chymotrypsin, trypsin, sodium periodate, and neuraminidase. HSF did not appear to have a serine group(s) in its "active" site since its biologic activity remained intact following treatment with an irreversible serine esterase inhibitor (phenylmethylsulfonyl fluoride). Further, HSF did not appear to have inter- or intra-molecular disulfide linkages because treatment with denaturing and/or reducing agents, followed by alkylation, did not significantly alter its activity. Molecular sieve chromatography employing Sephadex G-100 revealed an apparent molecular weight for HSF of 25-40,000. Electrophoresis of HSF in polyacrylamide gels at pH 8.7 under nonreducing conditions revealed two regions of activity, one region migrating with albumin and the other region anodal to albumin. In addition to suppressing lymphocyte proliferation, the 25-40,000 Mr Sephadex G-100 fractions also inhibited the production of leukocyte inhibitory factor. Of particular interest, gel filtration of supernatants generated by stimulating mononuclear cells with either histamine, dimaprit (but not 2-pyridylethylamine), concanavalin A, or candida albicans resulted in similar elution profiles with regard to inhibition of lymphocyte proliferation. That is, 25-40,000 Mr fractions of supernatants generated by each stimulant suppressed lymphocyte proliferation to a similar degree. The latter findings provide indirect evidence that T lymphocytes, triggered in response to antigen-specific and nonspecific stimuli, elaborate suppressor molecules capable of modulating T-cell function that share certain similarities.

Autologous mixed lymphocyte reaction in man. VII. Autologous mixed lymphocyte reaction in patients with bronchial asthma, allergic rhinitis and atopic dermatitis

The proliferative response of T lymphocyte cultured with autologous non-T lymphocyte is known as the autologous mixed lymphocyte reaction (AMLR). In AMLR, both helper and suppressor functions are generated. In this investigation we have examined T cell proliferative responses in AMLR in 12 patients with bronchial asthma, 10 patients with allergic rhinitis, and 10 patients with atopic dermatitis and compared that with simultaneously studied healthy controls. Our data show that the T cell proliferation in AMLR in patients with bronchial asthma is significantly higher than that of healthy normals. However, AMLR response in patients with allergic rhinitis or atopic dermatitis is comparable to controls. Mechanisms for increased AMLR in patients with bronchial asthma are discussed.