Abnormal lymphocyte function following long-term PUVA therapy for psoriasis

The surface markers and function of peripheral blood lymphocytes were examined in patients on long-term therapy with methoxsalen and UV-A radiation (PUVA). Ten patients with psoriasis were selected because they had received a high exposure to PUVA therapy, i.e., more than 200 treatments over 2-6 years with cumulative exposure doses of 1700-6000 J/cm2 UV-A radiation. Results were compared to those obtained with lymphocytes from untreated patients and UV-B treated patients with psoriasis. The PUVA-treated patients had low levels of E rosette-forming cells in the peripheral blood and markedly impaired lymphocyte responses following stimulation with optimal and suboptimal doses of mitogens. The sensitivity of lymphocytes to in vitro treatment with PUVA was similar in the three groups of patients. The results of this study indicate that long-term PUVA therapy alters the function and cell-surface markers or distribution of lymphocytes.

Collagenolytic activity of rabbit V2 carcinoma implanted in the nude mouse

The relative contribution of host cells and tumor cells to the production of collagenase and its regulation during tumorigenesis were studied with the use of a heterologous rabbit tumor-nude mouse host system. The V2 carcinoma, a malignant neoplasm of the New Zealand White rabbit, behaved as a nonmetastasizing, noninvasive tumor when implanted and grown in the inbred Swiss albino nude mouse. The extracts from both tumors contained similar levels of collagenase. Tumor explants also released enzyme into culture medium in both cases, but the rabbit tumor produced approximately 10 times more collagenase than the nude mouse. Freeze-thawing of the explants or treatment with cycloheximide markedly inhibited the appearance of enzyme in the medium from the rabbit tumor but not from the nude mouse tumor. The relative proportions of mouse- and rabbit-derived collagenase in the nude mouse tumor extracts and culture medium were determined with the use of antibodies specific for rabbit V2 tumor and mouse bone collagenases. Approximately 70% of the nude mouse tumor enzyme was derived from the rabbit tumor, and approximately 30% was derived from the mouse host. These findings indicate that the former might represent stored enzyme carried over during tumor transplantation into the nude mouse, whereas the latter might have originated from stimulation of host cells during tumorigenesis.

Reduction of the fraction of circulating helper-inducer T cells identified by monoclonal antibodies in psoriatic patients treated with long-term psoralen/ultraviolet-A radiation (PUVA)

Ultraviolet radiation has been found to alter the distribution and function of human lymphocytes. To determine whether photochemotherapy (PUVA) alters circulating levels of T cell subset marker-bearing lymphocytes, cells from 9 patients with psoriasis undergoing PUVA therapy for several years (mean 4.6 +/- 1.4 yr), 17 patients with active untreated psoriasis, and 20 healthy volunteers were reacted with monoclonal antibodies to T cell surface markers, including OKT3 (all peripheral blood T cells), OKT4 (helper/inducer T cells), OKT6 (common thymocytes), and OKT8 (suppressor/cytotoxic T cells), and analyzed by flow cytometry. There were no differences in the distribution of T cell subsets between healthy volunteers and patients with active psoriasis. In contrast, the percentages of lymphocytes reacting with OKT3 and OKT4 were lower (by 16% and 12% percent respectively, p less than 0.0025) in the PUVA-treated patients compared to healthy volunteers or patients with active psoriasis that had not received PUVA therapy. There was no difference in the percentage of OKT8 and OKT6 bearing cells. Squamous cell carcinoma of the skin subsequently developed in 2 of 3 PUVA-treated patients with the lowest percentages of T4-bearing cells. These findings indicate that long-term PUVA therapy is associated with a reduction in circulating helper/inducer T cells. This reduction may have a role in the altered immune function reported in PUVA-treated patients.

Enhanced production of IgE and IgG antibodies associated with a diet enriched in eicosapentaenoic acid

Eicosapentaenoic acid (EPA), a polyunsaturated fatty acid analog of arachidonic acid, alters certain platelet functions controlled by prostaglandins and thromboxanes, probably by inhibiting the synthesis of these molecules from arachidonic acid. This study reports the effects of a diet enriched in EPA (fish-fat diet, FFD) as compared with a diet lacking EPA (beef-fat diet, BFD) upon certain immunological and inflammatory responses in outbred Sprague Dawley rats. Induction of antibody formation to egg albumin (EA) produced four- to eight-fold greater titres of IgE (P<0.02) and IgG (P<0.03) anti-EA antibodies in FFD rats v. BFD rats. FFD rats had heightened active cutaneous anaphylaxis to EA, responding to a median [EA] of 10^-4 mg/ml, v. 10^-3 mg/ml in BFD rats (P<0.0032). Similarly, active Arthus reaction to EA in FFD rats was elicited to a [EA] of 10^-3 g/ml v. 10^-1 g/ml in BFD rats (P<0.01). Passive inflammatory reactions, as evaluated by passive cutaneous anaphylaxis elicited with IgE antibody, and by the intradermal injection of aggregated IgG, were not significantly different between the two groups. EPA constituted 7.3% of fatty acid in the livers of FFD rats, v. 0.3% in BFD rats (P<0.01). These data demonstrate enhanced levels of IgE and IgG antibody in FFD rats, with subsequent increased active inflammatory reactivity in these animals. These alterations may be secondary to enrichment of tissue lipids with EPA, although effects due to changes in other fatty acids have not been excluded.

Antibodies to human epidermal cytoplasmic antigens: incidence, patterns, and titers

Serum or plasma specimens were assayed in indirect immunfluorescence tests on cryostat sections of normal human skin for the presence and titer of antibodies reactive with human epidermal cytoplasmic antigens. A polyvalent fluorescein-labeled goat anti-human immunoglobulin antiserum was used in all tests. Three distinct staining patterns were noted: upper epidermal cytoplasmic fluorescence, U-CYT, produced by antibodies reactive with antigen present in cells of the upper and middle layers of the epidermis; general cytoplasmic fluorescence, G-CYT, produced by antibodies reactive with antigens present in cells throughout the epidermis; and basal cell cytoplasmic fluorescence, BCL, produced by antibodies reactive with components present only in basal cells. Sera from 8% of 52 normal blood donors produced the U-CYT pattern at dilutions greater than 1:10. The incidence of antibodies reactive with epidermal cytoplasmic antigens in patients with a clinical history of not more than 2 basal cell carcinomas of the skin was 5%, compared to an incidence of 89% in those individuals with 3 or more separate instances of skin neoplasms. There was no difference in the frequency with which cryosurgery was used in the treatment of skin neoplasms in either of these 2 groups. Antibodies to epidermal cytoplasmic antigens were also detected in 10% of patients with nondermatologic, nonpulmonary neoplasms, in 43% of patients with pulmonary neoplasms and in 1 of 11 patient with nonneoplastic diseases. Positive sera yielded titers ranging from 1:16 to 1:1024. The most common staining patterns noted in all of these cases were the U-CYT and G-CYT patterns; the BCL staining pattern was noted in only one instance.

Transport of proteases across neonatal intestine and development of liver disease in infants with alpha-1 antitrypsin deficiency

The transport of macromolecules from the intestinal lumen into the systemic circulation is considerably greater in neonatal than in adult animals. Transport of both immunoglobin and non-immunoglobulin proteins is enhanced. It is postulated that luminal enzymes are also transported into the systemic circulation of the neonate and reach the liver. In the absence of protease inhibitors, such as occurs in alpha 1-antitrypsin (alpha 1-AT) deficiency, these intestinal enzymes may cause inflammation and, eventually, fibrosis of the liver. If this hypothesis is valid, treatment with trypsin inhibitors and elemental diets until the excessive macromolecular transport across the intestine ceases may help to prevent the liver disease associated with (alpha 1-AT) deficiency.

In vitro assay for phototoxic chemicals

The photosensitizing potential of chemicals known to produce photosensitivity in humans was compared to chemicals not considered to be photosensitizers in an in vitro assay. The assay involved exposure of human lymphoid cells to UVA (320-400 nm), and in some cases UVB (280-320 nm) radiation, in the presence of the chemicals and the assessement of phototoxicity as measured by the incorporation of 3[H]-thymidine into nuclear DNA. All known photosensitizers tested were found to be phototoxic, while the nonphotosensitizing agents, with the exception of retinoic acid, were not phototoxic. Peripheral blood mononuclear cells were compared to a T lymphoblastoid cell line as target cells; the latter were superior in terms of convenience, cost and reproducibility of results. This test system has potential as a predictive assay for detecting additional phototoxic chemicals.

Hepatobiliary clearance of IgA immune complexes formed in the circulation

The formation and clearance of circulating IgA immune complexes from blood to bile was investigated in this study. The i.v. injection of either MOPC-315, an IgA M-component with antidinitrophenyl (DNP) specificity, or TEPC-15, an IgA M-component of a different specificity, was followed by i.v. injection of 125I-DNP10-bovine serum albumin (BSA) as the antigen. The formation and clearance of IgA immune complexes in the circulation of MOPC-315-treated, but not TEPC-15-treated animals was demonstrated by immunoprecipitation with polyacrylamide beads coated with rabbit anti-mouse IgA. IgA-125I-DNP10-BSA complexes were identified in the bile from MOPC-315-treated, but not TEPC-15-treated animals utilizing this same immunoprecipitation technique. These observations suggest that the liver or bile ducts transport IgA immune complexes from blood into bile. The clearance of 125I-DNP10-BSA from the circulation was documented by coprecipitation with rabbit anti-BSA and BSA. The clearance of this circulating antigen was slower in the MOPC-315-treated than in the TEPC-15-treated animals suggesting that under the conditions of the present experiment, circulating antigen is cleared more slowly after IgA immune complex formation.

Edema test for assessing ocular anaphylaxis

A technique for measuring the increase in conjunctival thickness which accompanies a clinically relevant, topically induced model of ocular anaphylaxis was developed and was compared with the determination of an increase in percent of degranulated mast cells in affected tissue. Twenty rats immunized with egg albumin were topically challenged with egg albumin solution applied to one eye and with phosphate-buffered saline applied to the other eye. Clinical signs of edema and erythema were not seen in ocular tissues undergoing anaphylaxis. However, both conjunctival thickness and percent of degranulated mast cells were significantly greater in antigen-challenged tissues than in buffer-challenged tissues. Amount of edema correlated significantly with amount of mast cell degranulation. Conjunctival thickness served as a reliable indicator of anaphylaxis. The measurement of topically induced anaphylaxis by evaluating the increase in conjunctival thickness was simpler, faster, and less expensive than the evaluation of anaphylaxis by the increase in the percent of degranulated mast cells in the same tissues.

Intestinal uptake of macromolecules. Differences in distribution and degradation of protein antigen in control and immunised rats

The present study examined intraluminal events in the in vivo processing of a protein antigen by the intestine of normal and orally immunised rats. One hour after the administration of 125I-bovine serum albumin (125I-BSA) and unlabelled BSA by gavage, the majority of the radioactivity was found in the distal small intestine of control and immunised rats but there was a difference in the distribution of radioactivity. In contrast with controls, immunised rats retained a lesser percentage of radioactivity in the proximal small intestine and a greater percentage of radioactivity in the distal small intestine. Radioactive substances present in intestinal rinse fluids and mucosal extracts were characterised by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), density gradient ultracentrifugation, and by immunochemical methods. Rinse fluids and mucosal extracts from immunised rats fed 125I-BSA by gavage contained high molecular weight components with characteristics of antigen-antibody complexes. Rinse fluids and extracts of normal rats contained more intact BSA and less fragments of BSA than did rinse fluids and extracts from immunised animals. These findings suggest that oral immunisation alters the distribution of antigen administered into the gut and that immunisation enhances the intraluminal degradation of antigen.

Use of hydrogen gas (H2) analysis to assess intestinal absorption. Studies in normal rats and in rats infected with the nematode, Nippostrongylus brasiliensis

The in vitro and in vivo production of hydrogen gas (H2) from various carbohydrates or proteins has been examined in normal rats and in rats infected with the nematode Nippostrongylus brasiliensis. Normal rat fecal homogenates were capable of producing H2 in vitro from glucose, sucrose, xylose, lactulose, bovine serum albumin, or casein hydrolysate. Direct injection of glucose, sucrose, xylose, lactulose, bovine serum albumin, or casein hydrolysate into the cecum of normal rats resulted in approximately twice as much H2 production in vivo than when these same carbohydrates or proteins were administered to the normal rats by gavage. Partial small intestinal villous atrophy was produced by infecting rats with the nematode N. brasiliensis. Impaired small intestinal cell function and evidence of malabsorption in the nematode-infected rats included: (a) decreased activity of intestinal cell lactase (-43%), sucrase (-33%), and alkaline phosphatase (-46%); (b) decreased gut sac uptake of 3-O-(methyl-3H]-D-glucose (-21%) or 1-[carboxyl-14C]-aminocyclopentane-1-carboxylic acid (-28%); and (c) increased (+ 64%-561%) 14CO2 production after D-[U-14C]xylose administration. These rats produced approximately twice as much H2 after gavage administration of glucose, sucrose, xylose, bovine serum albumin, or casein hydrolysate compared with normal rats. The present study suggests that H2 analysis may be useful in the evaluation of small intestinal malabsorption states in rats.

Ocular anaphylaxis: induction by local injection of antigen

A model of local ocular anaphylaxis has been developed in the rat. Erythema, oedema, and enhanced retention of radioiodinated rat serum albumin ([125I]-RSA) were noted in ocular adnexal tissues of immunized rats within 5 min of injection of antigen; these changes reached a maximum 15 min after antigen injection. Erythema, oedema, and retention of [125I]-RSA subsided to baseline levels 1--6 hr after challenge. A significant increase in weight of ocular adnexal tissues was seen within 15 min after challenge. The weight increase reached a maximum at 45 min and persisted through 6 hr. Weight approached baseline values by 24 hr. Although antigen was injected into the ocular adnexa and not directly into the globe, the globes of the antigen-injected eyes of immunized rats underwent anaphylaxis, possibly because of absorption of antigen through the sclera. In addition, the adnexa and globes of the contralateral eyes, which did not receive antigen, also underwent anaphylactic changes. These changes were not as marked as those observed in the antigen-injected tissues, but followed the same time-course of development. We conclude that anaphylaxis can be locally induced in ocular tissues, that the onset of anaphylaxis is within minutes, and the effects last for at least 24 hr.

Malignant lymphoma with dual B and T cell markers. Analysis of the neoplastic cells with monoclonal antibodies directed against T cell subsets

In the course of analyzing human lymphoma tissue with conventional surface marker techniques and with monoclonal antibodies directed against T cell subsets, five tumors were encountered with dual B and T cell determinants. All bore on their surface membrane IgM of kappa light chain type, complement receptors, and the Ia-like antigen. In each of the five cases, the neoplastic lymphocytes reacted with a monoclonal antibody that detects the sheep erythrocyte receptor (OKT11); all but one reacted with a monoclonal antibody for peripheral T cells (OKT3); and all but one reacted with a monoclonal antibody specific for either the inducer-helper (OKT4) or the cytotoxic-suppressor (OKT8) T cell subsets. In addition, lymphocytes from two of the five cases formed spontaneous rosettes with sheep erythrocytes (E-rosettes). These tumors with dual B and T surface characteristics were confined to human malignant lymphomas that originate from B lymphocytes of the follicle center.

Influence of PUVA and UVB radiation on delayed hypersensitivity in the guinea pig

Exposure of guinea pigs to UVA (320--400 nm) radiation following administration of 8-methoxypsoralen by gavage (referred to by the acronym, PUVA) or exposure to UVB (290--320 nm) radiation, produced suppression of the cutaneous delayed hypersensitivity reaction at the site of exposure to radiation and at distant nonexposed sites. In these experiments, the animals were immunized by injection of dinitrophenyl-bovine gamma-globulin (DNP-BGG) in complete Freund's adjuvant and delayed hypersensitivity responses were provoked by intradermal injections of DNP-BGG, DNP and BGG on the flanks. Exposure to erythemogenic doses of either PUVA or UVB radiation for 7 days prior to immunization and for the 7 days between immunization and challenge (total period of radiation: 14 days) produced inhibiton of responses to each of the test substances. In addition, treatment with erythemogenic doses of PUVA either for 7 days prior to immunization or during the interval between immunization and challenge with DNP-BGG, inhibited the delayed hypersensitivity responses at the site of irradiation and at a nonexposed site. These findings suggest that in vivo exposure to nonionizing radiation leads to both local and systemic alteration of certain immune responses.

Effect of locally induced intestinal anaphylaxis on the uptake of a bystander antigen

Adult Sprague-Dawley rats weighing 250 gm were immunized with 100 micrograms egg albumin (EA) and alum. Fourteen days later, intestinal anaphylaxis was induced by intraduodenal or intragastric challenge with EA. To test for the changes in vascular and mucosal permeability that accompany anaphylaxis, the rats were injected intravenously with 125I-rat serum albumin (RSA) at the time of challenge and the amount of radioactivity retained in the wall of gut segments, as well as the trichloroacetic acid (TCA)-precipitable radioactivity present in the secretions obtained from these segments, was determined. Enhanced retention of 125I-RSA was found in the wall of the duodenum and first and second halves of the small intestine, and increased amounts of TCA-precipitable radioactivity was found in gut segments obtained from antigen-challenged compared with buffer-challenged rats. In other EA-immunized rats bovine serum albumin (BSA) was administered by gavage 1 hr before challenge with EA. Increased amounts of immunoreactive BSA were detected by radioimmunoassay in the serum of rats subjected to local intestinal anaphylaxis. Possible consequences of the enhanced systemic uptake of protein present during local intestinal anaphylaxis were considered. It was suggested that such proteins might induce an IgE antibody response, thereby broadening the anaphylactic sensitivity of the animal to additional antigens.

In vivo effects of PUVA on lymphocytes function

Whole-body exposure to erythemogenic doses of PUVA in normal volunteer subjects resulted in a decrease in the proportion of circulating sheep erythrocyte rosette-forming and surface membrane immunoglobulin-positive lymphocytes and an increase in the proportion of null cells. Doses of PUVA resulting in minimal or no erythema had similar but less marked effects on lymphocytes. The changes appeared 30 min after exposure, were maximal at 12-16 h and returned to pre-treatment levels by 72 h post-irradiation. The response of lymphocytes to stimulation with phytohaemagglutinin was unaffected. No alteration occurred in the absolute numbers of circulating lymphocytes or polymorphonuclear leukocytes.

The influence of ultraviolet radiation on allergic contact dermatitis in the guinea-pig. I. UVB radiation

Guniea-pigs were sensitized by percutaneous application of dinitrochlorobenzene and exposed to UVB (280-320 nm) radiation. The exposure to radiation diminished the response to an elicitation dose of the hapten administered 14 days later within the site of irradiation. The exposure dose of radiation required to produce this effect resulted in a marked erythemal response, but this response did not conceal the contact allergic reaction. The site of elicitation of the allergic response had to be included in the exposure field.

Binding of exogenous protein fragments to native proteins: possible explanation for the overestimation of uptake of extrinsically labelled macromolecules from the gut

Investigators studying the transport of macromolecules across mucosal surfaces have noted that techniques involving exogenously labelled macromolecules result in estimation of transport which exceed estimates based on immunochemical methods. The present study tested the possibility that radio-labelled fragments of macromolecules might bind to host proteins resulting in an apparent increase in 'size' of the fragments. Fragments obtained by dialysis of bovine serum albumin (BSA) labelled with tritium gas by Wilzbach method, bound to normal rabbit serum in vitro and in vivo. Binding to BSA exceeded binding to bovine gamma globulin (BGG). Dinitrophenylated BGG was administered by gavage to adult rats; DNP-bearing fragments were identified in their serum and recovered by gel filtration. After radio-labelling, these serum fractions also bound to macromolecular constituents of normal rat serum. These findings suggest that several different fragments of proteins may bind to native serum components. These results may bear upon in vivo observations since it is likely that following intestinal instillation of extrinsically labelled protein, labelled amino acids or small peptides are generated by the digestive process, become absorbed, bind to serum macromolecules and thereby mimic the uptake of macromolecules.

The influence of ultraviolet radiation on allergic contact dermatitis in the guinea-pig. II. Psoralen/UVA radiation

Guinea-pigs were sensitized by percutaneous application of dinitrochlorobenzene and exposed to UVA (320-400 nm) radiation following systemic administration of methoxsalen. This treatment diminished the response to an elicitation dose of the hapten administered 14 days later within the site of irradiation. The site of elicitation of the allergic response had to be included in the field of exposure, an reduction of the allergic response was observed only when the exposure to radiation was commenced at the time of induction of contact allergy. Established contact skin sensitivity was not affected by radiation.

Degranulation of ocular mast cells in rats undergoing systemic anaphylaxis

The percentage of degranulated ocular mast cells in five egg albumin--immunized, systemically challenged rats was compared with that in five egg albumin--immunized, saline-challenged controls. For the lid and orbit, at least 100 mast cells per rat were evaluated. For the conjunctiva, tarsus, limbus, and episclera-sclera, at least 20 were evaluated. For the ciliary body and choroid, all mast cells in 15 sections separated by at least 15 micrometer were examined. The morphology of degranulated and intact mast cells was the same in the experimental and control animals, except for the change in granules. There were significantly more degranulated mast cells in most of the ocular tissues of rats undergoing systemic anaphylaxis than in tissues of controls rats; the increase in degranulated cells was especially striking in the choroid. We concluded that degranulation of mast cells is a measure of anaphylaxis, provided that the number of degranulated mast cells, and not simply the presence of such cells, is considered and compared with appropriate controls.

The influence of PUVA and UVB radiation on skin-graft survival in rabbits

The survival time of full-thickness skin grafts in rabbits was prolonged by administration of methoxsalen and subsequent exposure of the donor and recipient graft sites to longwave ultraviolet radiation (UVA). Erythemogenic doses of radiation were required to prolong graft survival. Similar exposure to mid-ultraviolet radiation (UVB) did not significantly prolong the survival time to grafts.