Natural killer cell activation and modulation of chemokine receptor profile in vitro by an extract from the cyanophyta Aphanizomenon flos-aquae.

The present research was designed to study the effects of an extract from the edible cyanophyta Aphanizomenon flos-aquae on human natural killer (NK) cells. We have previously shown, using a double-blind randomized placebo-controlled crossover design, that ingestion of 1.5 g of dried whole A. flos-aquae resulted in a transient reduction in peripheral blood NK cells in 21 healthy human volunteers, suggesting increased NK cell homing into tissue. We have now identified an extract from A. flos-aquae (AFAe) that directly activates NK cells in vitro and modulates the chemokine receptor profile. NK cell activation was evaluated by expression of CD25 and CD69 on CD3-CD56+ cells after 18 hours. Changes in CXCR3 and CXCR4 chemokine receptor expression after 5-60 minutes were evaluated by immunostaining and flow cytometry. AFAe induced the expression of CD69 on CD3-CD56+ NK cells, induced CD25 expression on 25% of these cells, and acted in synergy with interleukin 2. NK cells enriched by RosetteSep (StemCell Technologies Inc., Vancouver, BC, Canada) were not activated by AFAe, indicating that the NK activation was dependent on other cells such as monocytes. The low-molecular-weight fraction <5,000 of AFAe was responsible for the most robust NK cell activation, suggesting novel compounds different from previously reported macrophage-activating large polysaccharides.

Ginseng and Salviae herbs play a role as immune activators and modulate immune responses during influenza virus infection.

We have investigated the adjuvant roles of common herbal medicines (ginseng, Salviae) and their effects on early immune responses during influenza virus infection in a mouse model. Intranasal co-administration with inactivated influenza virus A (PR8) and ginseng or Salviae extract increased the levels of influenza virus specific antibodies and neutralizing activities compared to immunization with PR8 alone, and provided protective immunity. Salviae co-administration significantly enhanced IFN-gamma and IL-2 cytokine producing splenocytes while ginseng induced high levels of IL-4 and IL-5 cytokine producing cells after challenge infection. Cells expressing an early activation marker CD69 and levels of a pro-inflammatory cytokine IL-6 were highly elevated in lungs from naïve mice during challenge virus infection, which might be a mechanism in lung inflammation leading to death. In contrast, immunized mice that were co-administered ginseng or Salviae modulated CD69 expressing immune cells, did not produce IL-6, and showed significant enhancement of influenza virus specific IgA antibody in lungs after challenge virus infection. Therefore, these results indicate that both ginseng and Salviae play a role as mucosal adjuvants against influenza virus as well as immuno-modulators during influenza virus infection.

Effect of astragalus injection on serious abdominal traumatic patients' cellular immunity.

OBJECTIVE: To explore the change of serious abdominal traumatic patients' cellular immunity and the effect of Astragalus Injection (AI) on it. METHODS: Sixty-three serious abdominal traumatic patients were randomly assigned into two groups, the conventional group and the treated group, patients in the conventional group were given conventional treatment, while others in the treated group were given conventional treatment as the basis, with AI 20 ml was added into 250 ml of 5% glucose solution given through intravenous dripping, and then on the first day and 14th day, their T cell activated antigens as well as that of 10 healthy subjects were monitored. RESULTS: On the first day, in the conventional group and treated group, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), CD(16)(+), CD(69)(+) and CD(3)(+)/homologous leucocytic antigen-DR (HLA-DR(+)) were apparently lower than those in the healthy group (P < 0.05), while the CD(8)(+) was significantly higher than that in the healthy group (P < 0.05), and there was no significant difference between the conventional group and the treated group (P > 0.05); on the 14th days, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), CD(16)(+), CD(69)(+) and CD(3)(+)/HLA-DR(+) of the treated group got closed to healthy subject value, and got even higher than those of conventional group (P < 0.05); CD(8)(+) got close to that of healthy subjects, while obviously lower than that of conventional group (P < 0.05). CONCLUSION: After serious abdominal trauma, cellular immunity lowered, auxiliary use of AI was beneficial to the restoration of cellular immunity.

Increased liver temperature efficiently augments human cellular immune response: T-cell activation and possible monocyte translocation.

Hyperthermia (HT), in combination with other conventional therapeutic modalities, has become a promising approach in cancer therapy. In addition to heat-induced apoptosis, an augmented immunological effect is considered to be a benefit of hyperthermic treatment over chemo- or radiotherapy. Here, we investigated the effect of regional HT targeting the liver on immune cells, especially T cells and antigen-presenting cells, which are important in recognizing and eliminating tumor cells and pathogens such as viruses. In healthy volunteers exposed to such regional HT, both CD4(+) and CD8(+) T cells that express an activation marker CD69 increased transiently at 1 h post-treatment, with a subsequent decrease to base levels at 6 h after the treatment. At 24 h post-treatment, the percentage of CD69-positive cells significantly increased again but only among CD8(+) T cells. IFN-gamma production from PHA-stimulated peripheral blood mononuclear cells was gradually and significantly increased in the 2 days following the heating procedure, peaking at 36 h post-treatment. Furthermore, we found marked increases in plasma levels of IL-1beta and IL-6 starting at 24 h post-treatment. With regard to the number of each leukocyte subpopulation, a transient and dramatic decrease in the number of a subset of monocytes, CD14(+) CD16(-) cells, was observed at 1 h after the hyperthermic treatment, suggesting that the regional HT aimed at the liver may have influenced the extravasation of blood monocytes. No significant changes in T-cell activities or monocyte counts were observed in the volunteers exposed to heating of the lungs or the legs. These results suggest that heating of the liver may efficiently induce cellular immune responses to liver cancers.

Administration of a polysaccharide from Grifola frondosa stimulates immune function of normal mice.

We have reported that D-Fraction, a polysaccharide extracted from the edible maitake mushroom (Grifola frondosa), activates immunocompetent cells, thereby eliciting antitumor activity. To extend the application of D-Fraction as a nutritional supplement for healthy people as well as treatment for those with cancer, we investigated the effects of D-Fraction on the immune system in normal C3H/HeJ mice. Splenocytes from mice administered D-Fraction intraperitoneally for 17 consecutive days were cultured, and the culture supernatants were analyzed for nitric oxide (NO) and interleukin (IL)-12 production by antigen-presenting cells (APCs), including macrophages and dendritic cells, and also for the T helper (Th)-1 cytokine interferon (IFN)-gamma and the Th-2 cytokines IL-4 and IL-10. The level of IL-10 as well as those of NO and IFN-gamma were increased by D-Fraction as compared with the control, in which the serum immunoglobulin E level was increased. The results suggest that D-Fraction induced a Th-2 dominant response through the activation of macrophages, resulting in the enhancement of humoral immunity rather than cell-mediated immunity. Furthermore, an increase in the percentage ratio of CD69 and CD89 expression on major histocompatibility complex II(+) cells revealed activation of APCs 4 h after D-Fraction administration. These results indicate that D-Fraction enhances both the innate and adaptive arms of the immune response in normal mice. Therefore, its administration may enhance host defense against foreign pathogens and protect healthy individuals from infectious diseases.

The effects of ultraviolet B treatment on the expression of adhesion molecules by circulating T lymphocytes in psoriasis.

BACKGROUND: T lymphocytes are believed to play a role in the pathogenesis of psoriasis; > 80% of T lymphocytes that infiltrate psoriatic lesions express the surface glycoprotein cutaneous lymphocyte-associated antigen (CLA), compared with < 20% in the blood. Exposure to ultraviolet (UV) B is an effective treatment for psoriasis. OBJECTIVES: To compare the effects of UVB treatment of psoriasis on the expression of CLA and several other surface markers expressed by circulating T lymphocytes. METHODS: Peripheral blood mononuclear cells from psoriatic patients were stained for adhesion molecules and stimulated with streptococcal antigens before and once weekly during 3 weeks of UVB treatment. RESULTS: A marked and progressive decrease was observed during the treatment in expression of the CLA and the very late antigen-4alpha by T cells; this decrease correlated closely with clinical improvement (Psoriasis Area and Severity Index). T-cell expression of intercellular adhesion molecule-1 was not significantly affected during the treatment and no change was observed in the activation markers CD25 and CD69 or lymphocyte proliferation after stimulation with streptococcal antigens or superantigens. CONCLUSIONS: UVB treatment is associated with a marked reduction in the expression of skin-homing molecules by circulating T cells. This may be relevant to the therapeutic effect of UVB in psoriasis.

41.8 degrees C whole body hyperthermia as an adjunct to chemotherapy induces prolonged T cell activation in patients with various malignant diseases.

Whole body hyperthermia (WBH) has been used as an adjunct to radio-/chemotherapy in patients with various malignant diseases. Although clear evidence is still missing, it has been hypothesized that an activation of the immune system might contribute to the therapeutic effect of WBH. To examine whether a treatment with 60-minute 41.8 degrees C WBH as an adjunct to chemotherapy (WBH-CT) induces an activation of T cells, blood samples were collected at numerous time points before and up to 48 h post-treatment. The aim of this study was to examine the effect of WBH-CT on the expression of a broad range of activation markers on peripheral blood lymphocytes (PBL), on serum cytokines and intracellular cytokine levels in T cells, and the capacity of these cells to proliferate. Immediately after 41.8 degrees C WBH-CT treatment, a drastic increase in peripheral natural killer (NK) cells ( P<0.05) and CD56+ cytotoxic T lymphocytes (CTL; P<0.01) in the patients' peripheral blood was observed. At 5 h post-treatment, the percentages of both effector cell types had returned to baseline levels. This transient phenomenon was accompanied by a short period of reduced T cell activity, indicated by diminished serum levels of soluble interleukin-2 receptors (sIL-2R) at 3 h post-WBH-CT ( P<0.05) and decreased lymphocytic proliferation at the same point in time. This first phase was followed by a marked but short-lived increase in the patients' serum levels of interleukin-6 (IL-6; P<0.01) during the first 5 h following treatment, with a subsequent decrease to baseline levels at 24 h and significantly increased serum levels of tumor necrosis factor-alpha (TNF-alpha) at 0 h ( P<0.01), 3 h ( P<0.05), 5 h ( P<0.05) and 24 h ( P<0.01) post-WBH-CT. The third phase of the immunological consequences of WBH-CT consisted of an increase in the percentage of peripheral cytotoxic T lymphocytes (CTL) expressing CD56, reaching a maximum at 48 h post-WBH ( P<0.01). Furthermore, the percentage of CD4+ T cells expressing the T cell activation marker CD69 increased nearly two-fold over time, reaching its maximum at 48 h ( P<0.05). As an additional marker for T cell activation, serum levels of sIL-2R increased markedly ( P<0.01), reaching maximum levels at the same point in time. Elevated intracellular concentrations of interferon-gamma (IFN-gamma) and/or TNF-alpha in CD8+ T cells were found in 4 out of 5 patients at 24 h post-WBH-CT. Since similar changes were not observed in patients receiving chemotherapy alone, this is the first study to provide evidence for prolonged WBH-CT-induced activation of human T cells.

Comparison of inflammatory responses to genetically engineered hypoallergenic derivatives of the major birch pollen allergen bet v 1 and to recombinant bet v 1 wild type in skin chamber fluids collected from birch pollen-allergic patients.

BACKGROUND: Nearly 60% of birch pollen-allergic patients react exclusively to Bet v 1. With use of the skin blister model, previously only established for installation of crude allergens, we have for the first time characterized the inflammatory response in vivo to recombinant birch pollen allergen, rBet v 1, molecules (rBet v 1 wild type, fragments and trimer). OBJECTIVE: Our purpose was to examine whether challenge with rBet v 1 derivatives (fragments and trimer) compared with rBet v 1 wild type differs with respect to influx of activated eosinophils and detectable levels of cytokines/chemokines related to allergic inflammation in skin chambers applied to birch pollen-allergic patients. METHODS: The skin blister chambers were filled for 2 hours with rBet v 1, the derivatives or PBS and heparin (negative control). The fluids were analyzed after 2 and 8 hours. The number of eosinophils was determined and EG2 and CD69 expression measured by flow cytometry. Cytokines and mediators were analyzed by ELISA and RIA techniques. RESULTS: Comparable numbers of eosinophils were recruited to the chambers challenged with rBet v 1 molecules, but the eosinophils from the rBet v 1 wild-type challenged chambers showed a significantly higher expression of CD69. The levels of eotaxin were similar in all 4 chambers, whereas rBet v 1 wild type induced significantly higher levels of histamine, eosinophil cationic protein, and GM-CSF than the derivatives did. Recombinant Bet v 1 trimer elicited significantly lower levels of IL-4 compared with rBet v1 wild type. CONCLUSION: Genetically engineered hypoallergenic rBet v 1 derivatives recruited eosinophils analogously with rBet v 1 wild type. However, the derivatives exhibited a lower capacity to activate eosinophils and to release proinflammatory mediators and T helper type 2-derived cytokines. The derivatives may therefore be candidate molecules for specific immunotherapy of birch pollen allergy with reduced risk of inducing allergenic or inflammatory side effects.

Stress-compensation by a food supplement based on yeast plasmolysate in mitogen-activated T lymphocytes under simulated low-gravity.

T lymphocyte function is strongly depressed in vitro and in vivo under low-g conditions in space as well as simulated in clinostat. Here we describe the effect of a food supplement based on yeast plasmolysate on T cells activated in vitro with Concanavalin A and cultured in a random positioning machine. The mitotic index was measured by 3H-thymidine incorporation into DNA, the expression of activation markers CD25, CD69 and HLA-DR on the cell surface by cytofluorimetry and the secretion of the IL-2R by an enzyme immunoassay. Our data indicate that the food supplement used is capable to modulate T lymphocyte function. The addition of the food supplement increased the expression of activation markers in activated and non-activated cells. Cultivation under low-gravity conditions reduced the expression of the activation markers, but this expression was partly restored or even increased upon addition of yeast plasmolysate. On the other hand, cell proliferation and secretion of soluble IL-2 receptor was reduced after addition of the food supplement in all samples.

Cells and cytokines in pollinosis.

Pollinosis is a spontaneous model of allergic disease self limited in time. In order to evaluate immune response during pollen exposition cellular populations CD2, CD4, CD8, CD19, CD22, CD23, CD28, CD29, CD45RA, CD45RO have been studied before, during and after pollen season by flux cytometry. Simultaneous assays of soluble CD23 and cytokines IL-2, IL-4 and IL-2 soluble receptor have been done by an ELISA method. A decrease of CD23 PBC was observed during pollen season maintained afterwards without significant changes in sol CD23. The level of CD45RO memory cells decreased during pollen season with an opposed pattern for CD45RA naive cells. PBC expressing integrin chain CD29 were also decreased during the peak of pollen season. These results show that allergen exposition triggers a turnover of CD45 PBC, a decrease of low affinity IgE receptor CD23 in PBC and a consumption or binding of cells presenting the CD29 integrin chain. Cellular mechanisms are deeply implied in the immune response to pollens and cellular changes can be used as allergic inflammation markers in pollinosis.

An integrated model for the differentiation of chemical-induced allergic and irritant skin reactions.

Contact and photocontact allergic as well as irritant and photoirritant skin reactions represent a major problem in clinical dermatology and during the development of new pharmaceuticals. Furthermore, there is a lack of in vitro and in vivo assays that provide a clear differentiation between allergic and irritant skin reactions. Here, we describe an integrated model to differentiate between chemical-induced allergic and irritant skin reactions by measuring objective and easy-to-determine parameters within both skin and skin-draining lymph nodes. Dose-response studies with standard contact and photocontact allergens as well as irritants and photoirritants revealed that irritants predominantly induced skin inflammation, which in turn stimulated draining lymph node cell proliferation. In contrast, the induction phase of contact or photocontact allergy was characterized by marginal skin inflammation, but a marked activation and proliferation of skin-draining lymph node cells. Therefore, a differentiation index (DI) was defined describing the relation between skin-draining lymph node cell activation (lymph node cell count index) and skin inflammation (ear swelling). A DI > 1 indicates an allergic reaction pattern whereas DI < 1 demonstrates an irritant potential of a chemical. Experiments with the contact allergen oxazolone, the photocontact allergen TCSA + UVA, the irritant croton oil, and the photoirritant 8-methoxypsoralen + UVA confirmed the predictive value of DI. Furthermore, flow cytometric analysis of lymph node-derived T- and B-cell subpopulations revealed that contact sensitizer, but not irritant, induced the expression of CD69 on the surface of I-A+ cells. In conclusion, further studies with a broad range of irritants and allergens will be required to confirm general applicability.

Purified CD34+ Lin- Thy+ stem cells do not contain clonal myeloma cells.

High-dose therapy with autologous marrow or peripheral blood stem cell (PBSC) rescue has been extensively applied in the treatment of multiple myeloma (MM) patients during the past 10 years resulting in improved event-free and overall survival when compared with standard chemotherapy. However, relapses are common and cure is unlikely in the majority of patients. Because both bone marrow and PBSCs are contaminated with myeloma cells it is conceivable that relapse after autotransplantation originates at least in part from autografted tumor cells. In this study, mobilized PBSCs were examined for the presence of myeloma cells based on immunophenotyping and sensitive polymerase chain reaction (PCR)-based techniques. In addition, CD34+ Lin- Thy+ stem cells were purified from mobilized PBSC harvests of 10 MM patients by sequentially using counterflow elutriation centrifugation, treatment with phenylalanine methylester, and flow sorting, using 5-parameter gating (propidium iodide, forward scatter, side scatter, CD34+ v Lin- and CD34+ v Thy+). Virtually all mobilized unsorted PBSC preparations contained myeloma cells in sufficient quantities (range, < 0.01 to > 10%) potentially causing a disease relapse. Stem cell purification led to an overall enrichment by about 50-fold in all 10 patients; approximately 90% of the final cell population expressed CD34+ Lin- Thy+ with no evidence of myeloma cell contamination based on flow cytometric analysis of CD38bright cells (< 0.1%). Quantitative PCR amplification of patient-specific complementarity determining region III (CDRIII) DNA sequences showed depletion of clonal B cells by 2.7 to 7.3 logs, with the highest log reduction noted in the samples initially containing the most tumor cells. Our results show that purification of CD34+ Lin- Thy+ cells depletes myeloma cells to undetectable levels from up to 10% present in unsorted PBSCs, thus offering a tool to investigate whether MM relapse after autotransplantation can be reduced markedly.

Alteration in lymphocyte phenotype associated with administration of adjuvant levamisole and 5-fluorouracil.

Levamisole (LMS) and 5-fluorouracil (5FU) administered adjuvantly are effective in reducing the relapse rate following surgical resection of Duke's stage C colon carcinoma. It has been postulated that LMS acts to stimulate the immune system and that this is one mechanism through which this drug exerts its antitumor effects. In this study, peripheral blood mononuclear cells (PBMC) were analyzed in nine patients with surgically resected colon carcinoma prior to initiation of adjuvant LMS/5FU and at several subsequent times while patients were on therapy. Changes in lymphocyte phenotype and soluble interleukin-2 receptor (sIL-2R) between pre-study samples and samples obtained during adjuvant LMS/5FU were evaluated. Significant increases were seen in the proportion of PBMC expressing natural killer (NK) antigen CD56 (14.7 +/- 2.4% versus 18.1 +/- 2.6%; P < 0.05) and surface IL-2R (CD25; 0% versus 0.42 +/- 0.15%; P < 0.05), in sIL-2R (314 +/- 86 U/ml versus 736 +/- 173 U/ml; P < 0.05), and in the CD4:CD8 ratio (2.34 +/- 0.93 versus 3.47 +/- 1.23; P < 0.01). A significant decrease in the proportion of CD8+ PBMC (24.7 +/- 3.8% versus 18.8 +/- 2.6%; P < 0.01) and total CD8+ PBMC (537 +/- 118 versus 324 +/- 37; P < 0.01) was seen. The increase in CD56+ cells correlated with sIL2R levels (r = 0.46; P < 0.05). No changes were noted for CD3, CD4, CD5, CD14, CD16, CD19, CDw49a, or TCR delta. The greatest increase in CD56+ cells and the smallest reduction in CD8+ cells were seen in the subgroup of patients who remained disease-free following adjuvant chemotherapy. This study suggests that adjuvant LMS/5FU has significant stimulatory effects on the immune system, which correlate with patient outcome and may account at least in part for its clinical efficacy.

Correlation of clinical responses with immunologic and morphologic characteristics in patients with cutaneous T-cell lymphoma treated with interferon alfa-2a.

BACKGROUND: Immunophenotyping may aid in distinguishing more aggressive forms of cutaneous T-cell lymphoma (CTCL), thereby improving classification and treatment. OBJECTIVE: Our purpose was to investigate the relations between clinical, histologic, and immunophenotypic profiles in determining variables with respect to outcome. METHODS: Thirty-seven cases of histologically proven CTCL were analyzed in relation to clinical responses to treatment with interferon alfa alone or in combination with PUVA. Clinical stage, immunophenotyping, and histologic features were noted. RESULTS: All patients with no response to therapy had deletion of T-cell CD7 antigen. In contrast, only 21% of patients with a complete response had CD7 deletion. Deletion of the CD5 antigen occurred in 50% of patients with no response and in no patients with complete response. Large cell histologic features were found in 16% of patients with a complete response, 42% with a partial response, and 83% with no response. The presence or absence of other T-cell antigens and the clinical stage of disease did not correlate with outcome. CONCLUSION: Immunophenotypic analysis may be of greatest value in identifying a subset of high-risk CTCL patients, including those previously classified as low risk on the basis of clinical stage.

Immune disorders in depression: higher T helper/T suppressor-cytotoxic cell ratio.

This study investigated the leukocyte T helper and T suppressor-cytotoxic cell (sub)set profile of minor, simple major and melancholic depressives versus normal controls. Using both monoclonal antibody staining and flow cytometry, we determined the absolute numbers and percentages of the following T cell immune subsets: T helper (CD4+), T virgin (CD4+CD45+), T memory (CD4+CD45-), T suppressor/cytotoxic (CD8+), CD8+ T suppressor (CD8+CD57-) and CD8+ T cytotoxic (CD8+CD57+) cells. After computing the CD4+/CD8+ ratio, we detected a significantly increased ratio in depressed patients as compared with healthy controls. Depression per se is characterized by a higher percentage of CD4+ and a lower percentage of CD8+CD57- cells. Melancholic depressed subjects exhibit a significantly increased number of CD4+ and CD4+CD45- cells. The combined use of various percentages of CD4+ and CD8+ (sub)sets yields a high degree of marker positivity for melancholia: through cumulative evaluation of those percentages, the marker positivity increases to 68% (sensitivity) and the specificity is 95%. These results together with our previous reports may refer to a depression-related state of T cell activation.

Subsets of null and gamma delta T-cell receptor+ T lymphocytes in the blood of young pigs identified by specific monoclonal antibodies.

Rat monoclonal antibodies (mAb) against isolated pig Null T cells were derived using a novel two-colour cytofluorometric assay. One (MAC320) identified all blood CD2-sIg- 'Null' cells (present at up to approximately 6 x 10(6)/ml). Another type (MAC319 and MAC318) identified a subset comprising approximately 60% or approximately 30% of the Null cell population. This percentage appears genetically determined. This subset partially overlapped with a gamma delta T-cell receptor+ (TcR+) population which consisted of approximately 40% of Null T cells. The antibodies did not react with other leucocyte or lymphocyte populations. In non-reducing conditions, MAC320 precipitated two molecules at approximately 270,000-280,000 MW in SDS-PAGE; the larger of which was also precipitated by MAC319 (and MAC318, which binds to the same epitope). Under reducing conditions, MAC320 immunoprecipitated two or three polypeptide chains at approximately 130,000-160,000 MW; MAC319 precipitated only the largest of these polypeptides. The large MAC319+ MAC320+ molecule on one subset is removed by bromelain treatment; the smaller MAC319- MAC320+ molecule on the remaining Null cells is not bromelain sensitive. Several properties of this new antigen complex specific to pig Null T cells show that it is distinct from the ruminant T19 complex.

Eosinophil activation and T lymphocyte infiltration in allergen-induced late phase skin reactions and classical delayed-type hypersensitivity.

T lymphocyte infiltration is a well documented feature of classical delayed-type hypersensitivity (DTH) reactions. Recently, we have shown that T lymphocytes and activated (EG2+) eosinophils accumulate in the allergen-induced late phase skin reaction (LPR). To compare the kinetics and phenotypic composition of these T lymphocyte responses, LPR and DTH reactions of comparable induration size were induced in atopic subjects. In addition, DTH and LPR were compared between atopic and nonatopic subjects. In atopic individuals, allergen challenge elicited a perivascular influx of T lymphocytes that was predominantly CD4+. Eosinophil accumulation and activation were also prominent. There was no cellular response to allergen challenge in the nonatropic group. In both groups, DTH responses showed an intense T cell infiltrate which was more dense and dispersed than in the LPR. CD4+ T cells predominated but at 48 h CD8+ numbers were also significantly increased. In DTH, total leukocyte numbers (CD45+) were increasing at 48 h, whereas in the LPR, cell numbers reached a plateau between 24 and 48 h. T cell activation (shown by expression of IL-2R) was more prominent in DTH. Endothelial expression of HLA-DR was increased in both LPR and DTH, implying the local release of inflammatory cytokines in both reactions. Small but significant numbers of activated eosinophils (EG2+) were detected in atopics and non-atopics at 24 h in DTH but not at 48 h. These findings suggest that the allergen-induced LPR induced in atopic subjects is, at least in part, a form of cell-mediated hypersensitivity but with T cell kinetics that differ from classical DTH.

Lymphopenia and decrease in the total number of circulating CD3+ and CD4+ T cells during 'long-term' PUVA treatment for psoriasis.

The relationship between high-dose PUVA treatment in psoriatic patients and peripheral T lymphocyte subsets (total number and percentage) has been studied. Of the two groups of patients considered, the first included 19 patients, all affected by chronic, progressively worsening psoriasis; they had never been previously treated by photochemotherapy. The second group included 13 psoriatic patients, who had received an average cumulative dose of 2,007.69 +/- 1,191.05 J/cm2. The 'long-term' PUVA-treated group was assessed while undergoing maintenance therapy. No significant differences were found between untreated patients and healthy controls for any of the parameters considered. A significant reduction (p less than 0.05) in the total number of lymphocytes in long-term PUVA-treated patients both versus untreated patients and controls was found. Furthermore, long-term PUVA-treated patients showed a significant reduction (p less than 0.05) in the percentage of lymphocytes as compared with controls. The reduction in the total number of CD3+ and CD4+ T cells was, moreover, significant (p less than 0.05) as compared with untreated patients. The impairment of circulating CD3+ and CD4+ T cells (total number) was only on the borderline of statistical significance vis-à-vis controls. These findings suggest the usefulness of a careful assessment of circulating T lymphocyte subsets in patients who undergo long-term PUVA therapy.