Search

Preincubation of peripheral leukocytes from atopies and normals significantly enhanced histamine release induced by anti-IgE and calcium ionophore. On the other hand, there was a significant inhibition (ca. 40%) of C5a-induced histamine release by indomethacin both in atopies and controls. In the group of patients with atopic eczema, anti-IgE-induced histamine release was significantly higher than in controls both without and with indomethacin.

Die Forderung des Arzneimittelgesetzes [1] nach einer Kennzeichnung der Fertigarzneimittel nach Darreichungsformen wird fur die Dermatika bisher in keinem Arzneibuch ausreichend erfullt. Die Rote Liste [2] nennt unter „Externa“37 Zubereitungsformen, wobei gleiche haufig unterschiedlich bezeichnet werden.

In der auserlichen Behandlung von Hauterkrankungen steht neben der Auswahl des Wirkstoffes gleichberechtigt die Wahl der Grundlage, der nicht nur Reglerfunktion als Vehikel zukommt, sondern eigenstandige therapeutische Wirksamkeit. Sie „entfaltet auf Grund ihres physiko-chemischen Charakters therapeutische Effekte, ist also auch selbst Arzneimittel“[1]! Besonders bei akuten Hauterkrankungen kommt der Auswahl der Grundlage entscheidende Bedeutung zu (z.B. feuchter Umschlag), wahrend bei chronischen Dermatosen oft eine Therapie mit reinem Wirkstoff durchgefuhrt wird (z.B. Teer-Anstrich).

Horse anti-human lymphocyte globulin (ALG) solutions contain, like human γ-globulin preparations, a varying amount of IgG aggregates, which increase during longer periods of storage. Aggregate formation does not impair the immunosuppressive potency of ALG, as has been shown by prolongation of skin allograft survival time in primates. Deaggregated ALG, which can be obtained by ultracentrifugation at 100,000 g over 2 h, is less immunogenic than aggregate containing ALG. The clinical compatibility of ALG was significantly improved by ultracentrifugal deaggregation.

A new, standardized, ready-to-apply patch test, the TRUE Test™, has been evaluated on 698 consecutive patients with suspected contact dermatitis. The patients were tested with 12 different allergens. Simultaneously, the same 12 allergens in pet. (Trolab®) were applied symmetrically to the opposite side of the upper back using the conventional Finn Chamber® technique. There were positive test reactions to all 12 allergens lusted in the patient group. The concordance of positive reactions between the TRUE Test™ and the Finn Chamber® test was 67%; 13% of all positive reactions were recorded only for the TRUE Test™ and 20% only for the Finn Chamber® method. The frequency of questionable and irritant reactions was of the same low order of magnitude for both tests methods; such reactions were recorded an around 2% of all test patches.

Unvertraglichkeitsreaktionen konnen auf sehr unterschiedlichen Mechanismen beruhen (Tabelle 1). Ihre Diagnostik mus zum Ziel haben, sowohl den krankheitsursachlichen Ausloser zu identifizieren als auch den zugrundeliegenden Pathome-chanismus aufzudecken. Handelt es sich um allergische Uberempfindlichkeitsreaktionen, so ist zu versuchen, den Reaktionstyp entsprechend der Einteilung von Coombs und Gell aufzuklaren. Lediglich fur die Diagnostik allergischer Reaktionen gibt es praktisch anwendbare In-vitro-Verfahren, fur die haufigen nichtimmunologischen, pseudo-allergischen Reaktionen sind keine entsprechenden Testsysteme verfugbar. Wichtige In-vitro-Untersuchungen bei allergischen Erkrankungen sind in Tabelle 2 angefuhrt. Im Gesamtplan der allergologischen Diagnostik kommt In-vi-tro-Tests die Rolle von Screening- oder Bestatigungsreaktionen zu.

Both ionic and nonionic, monomeric and dimeric contrast media were found to release serotonin from intact human platelets in vitro. The monomeric contrast media were compared at the concentration range of 25 mg I/ml. Iothalamate was the strongest and the statistically equal metrizamide iopamidol, and P-297 were the weakest releasers. Monomeric and dimeric contrast media were compared at concentration ranges of 50 and 100 mg I/ml. They ranked, in descending order of serotonin releasing potency: iodipamide, iothalamate, P-127, iopamidol, and a statistically indistinguishable group of the monoacid dimer P-286, the nonionic dimer ZK 74 435, and metrizamide. The capability of contrast media to release serotonin seems to be a composite result of their specific physical and molecular structural properties.

The immunofluorescent patterns of uninvolved and involved skin biopsies from eight patients with atopic dermatitis were studied, using direct immunofluorescence techniques to identify deposits of the immunoglobulins G, A and M as well as the complement factors C1q, C3, C4, C5, factor B and properdin. Immunoglobulin deposits (mainly IgG) were found in five patients, complement deposits in three patients in the basement membrane zone. In three patients the immunofluorescence was positive for C3, in two patients for C1q, C4 and C5. Regarding the factors of the alternative pathway of the complement system, two patients showed deposits of properdin, one of factor B. The changes were not confined to the eczematous lesions, but were found in uninvolved skin too. The most prominent changes were observed in patients with severe disease.

Two groups of dogs received daily intravenous doses of 20 mg/kg 131-I-labelled horse-anti-dog lymphocyte globulin or normal horse gammaglobulin respectively over a period of 11 days. Horse-anti-dog lymphocyte globulin showed a significantly higher eleimination rate than normal horse gammaglobulin. In contrary to the continuous increase in serum radioactivity during normal horse gammaglobulin treatment, there was a plateau after the 5th day in the horse-anti-dog lymphocyte globulin group. The xenogeneic protein concentration, measured with the single radial immunodiffusion technique, at the end of treatment was 165 +/- 8 mg/1 in the horse-anti-dog lymphocyte globulin, compared to 498 +/- 15 mg/1 in the normal horse gammaglobulin group. After treatment horse-anti-dog-lymphocyte globulin treated animals showed a significantly higher increase in active hemagglutination titer against horse erythrocytes with an average of 2(-8).

Sheep red blood cells were stabilized with sulfosalicylic acid and sensitized with purified horse-IgG by the action of glutardialdehyde. The cells were used in an indirect microhemagglutination test with serum samples from 12 rabbits immunized with horse-IgG and complete Freund’s adjuvant as well as from 10 control animals. 32 human serum samples were examined, 6 of them from patients with established horse protein allergy. The results were compared to those of a standard method of indirect hemagglutination using fresh human erythrocytes (group·Rh––), an active hemagglutination test against horse erythrocytes, Ouchterlony’s immunodiffusion and skin tests with horse-IgG. The method proved to be very sensitive. The results correlated well with those of the other immunological techniques. The stable sensitized cells did not lose sensitivity after 1 year of storage at 4°C.

Unter Seborrhoe (sebum = Talg) versteht man eine uber die Norm gesteigerte Talgproduktion [1], Man unterscheidet: Fette Seborrhoe: Uberproduktion eines dunnflussigen, oligen Sekrets, die zu fetter glanzender Haut fuhrt. Trockene Seborrhoe: Bildung von zahem, wenig gleitfahigem Sekret, die eine juckende, schuppige Haut verursacht. Seborrhoische Erkrankungen treten bevorzugt an Hautstellen mit reichlich Talgdrusen auf, wie z. B. am behaarten Kopf, im Gesicht, am Hals, im Nacken sowie an Brust und Rucken.

The major problem of detecting reaginic antibody by passive cutaneous anaphylaxis (PCA) is the quantitation of the dye reaction. Radiolabelled antigen was used in an attempt to quantitate the PCA reaction (Radio-PCA). Antisera containing reaginic antibody against human serum albumin (HSA) were produced in rabbits. These antisera were injected into normal rabbit skin in different dilutions. Twenty-four hours later HSA was injected intravenously either with Evans Blue or as 125-I-HSA. Radioactivity found in antibody-containing skin was significantly higher than in control specimens containing saline or normal rabbit serum, as low as antiserum dilutions of 1:1,000. Compared with the Evans Blue technique Radio-PCA was able to distinguish quantitatively between different antiserum dilutions at a higher level of statistical significance.

Der Begriff „Atopie“ ist jung, obwohl er eine altgriechische Vokabel benutzt. Er wurde 1923 von dem Altphilologen Perry der Columbia Universitat gepragt und zwar auf Wunsch von Coca und Cooke, die damit eine beim Menschen beobachtete, familiar auftretende, „abnormale“ Form von Uberempfindlichkeit gegen Umweltallergene ohne vorausgehende Sensibilisierung (z. B. Asthma, Heuschnupfen) von anderen Formen der Uberempfindlichkeit (wie z. B. Anaphylaxie) abgrenzen wollten [3].

The influence of arachidonic acid (AA) metabolism upon histamine release (HR) from human basophils after stimulation with anti-IgE was studied in 23 atopic and 11 normal individuals. HR occurred significantly faster in atopics than in normals; the total amount of HR after a 40 min incubation period was not significantly different between the two groups. Indomethacin and acetylsalicylic acid (ASA) increased the quantity of HR significantly both in atopics and normals without influencing the time course. Addition of exogenous PGE2 decreased HR; here atopics were more affected than normals 5 and 10 min after challenge with anti-IgE. Production of PGE2 after stimulation with anti-IgE was very low in both groups (in the range of 30-50 pg/10(6) cells) and often below detection limit (10-20 pg/ml). Addition of glutathione (GSH), a coenzyme of PGE2-isomerase, increased PGE2 production 2 to 5-fold during stimulation with anti-IgE. These data support the idea that arachidonic acid metabolites play an important role in modulating the "releasability" of human basophils. It is suggested that the basophils of atopic individuals may release their histamine faster than normals - perhaps on the basis of a more slowly acting endogenous feedback mechanism by PGE2. Both phenomena support the idea of an altered "releasability" of basophils from atopics compared to normals.

Das Thema „Immunglobuline“steht sicher nicht ohne Grund am Ende dieser Diskussion uber die Therapie mit Blutkomponenten. Zu einer Reihe von Fragen bestehen hier noch kontroverse Meinungen. Paradoxerweise reicht der therapeutische Einsatz von Immunglobulinen bereits in das vorige Jahrhundert zuruck. E. von Behring legte 1890 mit der Anwendung xenogener Eiweiskorper in Form eines Antidiphtherieserums vom Schaf den Grundstein zur passiven Immunisierungsbehandlung. Sensibilisierungserscheinungen gegen das artfremde Eiweis verhinderten in den folgenden 50 Jahren eine weite Verbreitung dieser Therapie. Es war deshalb ein groser Fortschritt, als Anfang der 40er Jahre humane Gammaglo- bulinpraparate mit Hilfe des von COHN eingefuhrten Fraktionie- rungsverfahrens isoliert und klinisch eingesetzt werden konnten. Mit der Prophylaxe gegen Viruserkrankungen, insbesondere gegen Masern und infektiose Hepatitis, hatten Stokes und Neefe (31) erste Erfolge erzielt. Als Bruton et al. 1952 (4) das angeborene Fehlen der Gammaglobuline im Serum von Kindern als Ursache fur rezidivierende bakterielle Infekte erkannten, bestatigte sich klinisch, das die Gammaglobulinfraktion alle Antikorperaktivitaten des menschlichen Serums enthalt. Es zeigte sich, das bei Patienten mit Antikorpermangelsyndrom (AMS) durch Anwendung von Gammaglobulinen auch bakterielle Infektionen zu verhindern waren (28). Aus diesem Grund wurde das nur i. m. applizierbare Praparat auch bald bei bakteriellen Infektionen jeglicher Art erprobt, ohne das dabei ahnliche Erfolge zu erzielen waren (2).

Until now the number of clinically used nonsteroidal antiinflammatory drugs (NSAID) increased up to fourty. Some of these NSAID are known to exert photosensitizing effects.

Fifteen patients with atopic dermatitis were investigated to evaluate the total of complement and histamine. In five patients total serum complement haemolytic activity (CH50) was significantly decreased as was the haemolytic activity of complement components C2 (C2H50) and C3 (C3H50). By counter immunoelectrophoresis split products of C3 were detected. There was no evidence for alternative pathway activation or the presence of an activator of the alternative pathway. In three patients plasma histamine concentrations were elevated. The intensity of the complement and histamine changes observed seemed to be correlated to the severity of the disease.

Although known for almost 80 years, histamine (H) (β-imidazolylethylamine) still remains a fascinating substance for many researchers. In spite of great progress in knowledge of pharmacology and release mechanisms as well as the discovery of other potent mediators, the definition of the physiological role of histamine in health and disease remains incomplete. The role of H — among others — as mediator of immediate-type hypersensitivity diseases (both allergic and pseudo-allergic in origin) is rather well established. This proinflammatory effect involves predominantly H1 receptors on mucosal cells, smooth muscle and vascular endothelium. Similarly well-defined is the H2-mediated role of H in gastric acid secretion. Less well defined is the clinical relevance of cardiac H1 and H2 receptors (atrial H1 receptors mediating negative dromotropic effects, while ventricular tachycardia is mediated by H2 receptors) as well as the role of H as neurotransmitter in the human brain.

The interrelation between immediate and delayed hypersensitivity reactions to local anesthetics is poorly understood. Especially, the relevance of positive patch test reactions to local anesthetics with regard to the compatibility of injected local anesthetics is unclear. We therefore subjected 104 patch test—positive probands to prick and intradermal tests with seven local anesthetic agents. All prick tests were negative. Only 14 patients showed positive reactions in intradermal tests: 11 with the ester local anesthetic procaine, one with the amide local anesthetic butanilicaine, and two with both. Procaine yielded both immediate and delayed reactions; butanilicaine, only immediate reactions. All other local anesthetics showed negative reactions. It is concluded that in patients with positive patch test reactions to local anesthetics and negative history of anaphylactoid reactions, positive skin test reactions to intradermal application are rare and that, therefore, the risk of anaphylactic reactions to injection anesthesia with amide local anesthetics, except butanilicaine, appears low in these patients.

Investigations in 30 paraplegic patients and ten voluntary controls showed that in paraplegics the albumin elimination rate is significantly increased with the highest values of 35.2 ± 6.5 per cent/hour in tetraplegics compared to normal values of 76 ± 0.5 per cent/hour. This finding could not be explained by immunological mechanisms. There were no antibodies against human albumin in the sera of the patients nor positive skin tests. The disappearance curve of homologous and autologous 125-J-Albumin according to the antigen elimination technique corresponded without difference to a normal metabolic situation. Clinical criteria (height of the lesion) indicate that permeability changes due to central nervous mechanisms may be regarded as an aetiologic factor. A chronic pressure sore can accentuate the symptoms by its additional protein loss.

Incompatibility reactions due to hydroxyethyl starch (HES) were observed during 8 out of 10,273 infusions of 500 ml 6% HES (Plasmasteril). The clinical symptoms ranged from skin reactions to tachycardia, hypotension and shock. In 3 of the 8 patients with incompatibility serum immunoglobulin concentrations were reduced after the anaphylactoid reaction. Specific antibodies against HES were, however, not detected. Serum IgE levels stayed within their normal limits. Positive reactions of the immediate type to intradermal skin tests with different dilutions of Plasmasteril were obtained in five patients.

In a double blind study, alcohol/onion extract (5% ethanol) was injected simultaneously with 20 IU and 200 IU rabbit anti-human-IgE intradermally in 12 adult volunteers (6 atopics, 6 non-atopics). Diameters of wheals and flares were measured 10 min after and compared with control sites challenged with 20 IU and 200 IU anti-IgE in a 5% ethanol solution. The skin sites were then treated epidermally with 45% alcohol/onion extract and 45% ethanol under occlusion. Diameters of late cutaneous reactions were measured hourly. Oedema formation was clinically estimated according to an arbitrary scale and skin thickness measured with a calliper. In the onion-treated skin sites the wheal areas were significantly reduced (20 IU: control: 108 +/- 53 mm2; onion 69 +/- 42 mm2, P less than 0.05; 200 IU anti-IgE: control: 152 +/- 25 mm2, onion: 138 +/- 26 mm2, P less than 0.02). The oedema formation during the late phase skin reaction was markedly depressed (P less than 0.005 at 2 h, P less than 0.01 at 4 and 6 h, P less than 0.02 at 8 h). The extent of late skin reactions was slightly, but not significantly reduced. Obviously, onions contain pharmacologically active substances with anti-inflammatory and/or allergic properties.

Am Beginn einer Abhandlung uber Wirkstoffe in der dermatologischen Therapie mus die Betrachtung der besonderen Gegebenheiten stehen, die die auserliche Dermatotherapie kennzeichnen.

Bevor die Ergebnisse der klinisch-immunologischen Untersuchungen bei Patienten mit anaphylaktoiden Reaktionen nach Kolloidinfusion interpretiert werden konnen, mussen die Basiswerte von Kontrollpatienten, die unter ahnlichen klinischen Bedingungen kolloidale Volumenersatzmittel erhalten, bekannt sein. Abgesehen von einigen Berichten uber das Verhalten der Immunglobuline (85) fehlen jedoch derartige Kontrollwerte fur beinahe alle im Zusammenhang mit dieser Arbeit interessanten unspezifischen und spezifischen immunologischen Parameter.

Peripheral blood leukocytes from fifteen patients with atopic dermatitis and ten normal nonatopic volunteers were incubated with various stimuli in vitro, and the release of the lysosomal beta-glucuronidase into the supernatant was measured. beta-Glucuronidase release was significantly reduced in patients with severe atopic dermatitis after stimulation with aggregated IgG, horse antihuman lymphocyte globulin (ALG), zymosan, and yeast-activated serum. There was an indirect correlation (r = -0.83) between aggregated IgG-induced beta-glucuronidase release and the intensity of clinical symptoms; however, there was no correlation with serum IgE levels. The enzyme release measured was not caused by cellular lysis, except for high concentrations of antilymphocyte globulin, as determined by lactic dehydrogenase (LDH) activity in the supernatant. It is concluded that lysosomal enzyme release defects might be involved in the well-known decreased resistance to infections in patients with atopic dermatitis.

Postoperative Infektionen sind trotz Verwendung von Antibiotica und verbesserter Masnahmen der Krankenhaushygiene nach wie vor haufig (2). Da die Wirksamkeit von i.v. GG gegen bakterielle Infektionen noch immer umstritten ist (1), wurde die Effektivitat eines heute gebrauchlichen Praparates in einer kontrollierten, randomisierten klinischen Studie gepruft. Dabei stellten sich folgende Fragen: 1. Wie hoch sind die Immunglobulin (IG)-Verluste nach langdauern den Operationen? 2. Wie verhalten sich die Ig-Spiegel bei Auftreten einer postoperativen (p.op.) Infektion? 3. Ist hochdosierter GG-Ersatz in der Lage, den p.op. Verlust von IgG rasch auszugleichen? 4. Fuhrt der hochdosierte GG-Ersatz zu einer Verminderung der p.op. Infektionshaufigkeit?

Desinfektionsmittel sind keimtotende Stoffe mit Wirkung auserhalb des menschlichen Organismus.

“Mild” analgesic preparations (MAP), containing as main active compounds salicylates, pyrazolons, or p-aminophenol derivatives, are well-known elicitors of AR. The identification of the responsible agent is often difficult, as routine skin tests are only rarely conclusive.

Der Kurs „Angewandte Allergologie“ befaste sich mit dem Kontaktekzem, einer der haufigsten Hauterkrankungen in der dermatologischen Praxis. Ausgehend von den immunologischen Grundlagen setzten sich die Referenten mit praktischen Fragen der Durchfuhrung von Epikutantesten, der Abgrenzung von toxischen Reaktionen bis hin zur rechtlichen Problematik einer Begutachtung auseinander. Daneben wurden spezielle Fragen, wie z. B. die Phytoallergene und die photoallergischen Kontaktekzeme diskutiert.

Sexualhormone finden dann berechtigterweise Eingang in die dermatologische Therapie, wenn es darum geht, entsprechend hormonell gesteuerte Prozesse zu beeinflussen. In Tabelle 14.1 sind kurz die wesentlichsten Wirkungen der verschie-denen Hormone auf die Haut und ihre Anhangsgebilde aufgefuhrt [1–6].

Die klinisch-immunologische Untersuchung von Patienten unter ALG-Therapie, wobei eine grose Menge (bis zu 50 mg pro kg) eines xenogenen Eiweises intravenos appliziert wird, bietet die seltene Gelegenheit, die verschiedenen Entstehungsmechanismen einer anaphylaktoiden Reaktion und deren Vermeidung zu studieren. Das immunologisch definierte xenogene System erleichtert die Unterscheidung von immunologisch induzierten und durch andere Mechanismen hervorgerufenen anaphylaktoiden Reaktionen. Selbstverstandlich steht die immunologisch bedingte Reaktion im Vordergrund des Interesses.

The effect of UV-A radiation on the in vitro release of vasoactive mediators from human peripheral leukocytes incubated with different nonsteroidal antiinflammatory drugs (NSAIDs) was studied in the newly developed photo basophil histamine release test (PBHRT). Washed peripheral leukocytes were incubated with 10––6 to 10––3M of various NSAIDs and exposed to 1–100 J/cm2 UV-A. Maximum histamine release was 4% with acetylsalicylic acid, 10% with benoxaprofen, 20% with thiophene, 28% with diclofenac, 39% with tiaprofenic acid, 40% with carprofen, 55% with ketoprofen and not demonstrable with indoprofen. Maximal reactions occurred at UV-A doses of 25 or 50 J/cm2. Leukotriene B4 (LTB4) generation in the supernatants of cells treated with UV-A or NSAID alone was below or close to the detection limit (145 pg/ml). On the contrary, UV-A irradiation of cells incubated with NSAID led to marked LTB4 generation (up to 1,000 pg/ml). The results indicate that many NSAIDs can induce photosensitization in vitro, the PBHRT being a promising new method for identification of possibly phototoxic compounds. Release of vasoactive mediators like histamine or leukotrienes may be involved in the in vivo development of phototoxic or photoallergic side reactions.

Cases of fatal hypersensitivity reactions have been described in the history of medicine for several thousand years [44, 62]. However, it was only in 1902 that Richet and Portier conducted their experiments on the yacht of the Prince of Monaco, describing and naming this dramatic condition “anaphylaxis” — distinguishing the phenomenon from “prophylaxis” achieved by repeated injection of biological materials [39].

Summary Apparently normal, and lesional skin from patients with atopic eczema were investigated immunohistochemically with anti-HLA-DR, -CD1a and -IgE antisera. A CD1a + intercellular pattern was observed in uninvolved skin in the majority of the patients whereas an HLA-DR +/CD1a+ network, mostly localized in basal and supra-basal areas, was shown in lesional skin of virtually all of them. Moreover, an HLA-DR +/CD1a + IgE + intercellular pattern was observed in some of the patients only and was predominantly localized in those areas characterized by lymphocyte exocytosis, spongiosis or vesicle formation. Whether keratinocytes are able to synthesize CD1a antigen and FcɛR or if these molecules are only produced and shed by CD1a +/IgE + epidermal dendritic cells remains unclear.

Zahlreiche in der dermatologischen Therapie eingesetzte Wirkstoffe weisen „an-tientzundliche“Eigenschaften auf; das fangt bereits bei den indifferenten Basis-wirkstoffen (z.B. Zinkoxid) an und umfast eine Reihe von Stoffen, die in den Kapiteln 10, 11, 13 und 15 besprochen werden. Im folgenden sollen einige speziell durch ihre antiphlogistischen Eigenschaften wirkenden Substanzen gesondert vorgestellt werden.

Im folgenden Kapitel wird die Symptomatik der anaphylaktoiden Reaktionen nach Infusion verschiedener Kolloide phanomenologisch vorgestellt. Die Intensitat der beobachteten Reaktionen wurde dabei nach einer Schweregradskale (Tabelle 25) quantitativ erfast. Die in vielen Fallen so dramatische klinische Situation gab schlieslich Anlas und Motivation fur die vorliegende Arbeit. Der deskriptive Teil wird erganzt durch die vergleichende Erfassung der Haufigkeiten anaphylaktoider Komplikationen nach Infusion kolloidaler Volumenersatzmittel; nur auf der Grundlage dieser Zahlen kann die Problematik der Zwischenfalle quantitativ beurteilt werden.

Summary Plasma histamine concentrations were determined using a radio-enzymatic assay in fifty-four patients suffering from atopic eczema and in thirty-nine controls (contact dermatitis, psoriasis and normal non-alopic healthy volunteers). While in none of the controls histamine levels in plasma exceeded 1 ng/ ml, seventeen out of fifty-four patients with atopic eczema showed increased plasma histamine concentrations ranging between 1-2 and 5′2 ng/ml. Elevated plasma histamine levels were found mostly in patients with severe eczema and high serum IgE. levels. Longitudinal studies in seven patients revealed normal plasma histamine values during clinical remission.

Anaphylactoid reactions have been reported in association with all of the currently available plasma substitutes. The clinical picture ranges from skin reactions only to severe and life-threatening complications, which can be conveniently classified into four grades of severity. The pathomechanism of these anaphylactoid reactions varies for the different colloids. Anti-dextran antibodies (most likely IgG) seem to be responsible for severe DIAR representing an immune complex anaphylaxis. IgE has not been implicated in reactions of this type. Skin tests seem to be of limited value in the diagnosis of dextran reactions and should be performed with great caution. Administration of a specific hapten (low-molecular-weight dextran) prior to dextran infusion reduces the frequency of DIAR in animals and humans. The principal mediator of anaphylactoid reactions due to gelatin infusion is histamine, and this has been established for urea-linked gelatin. It is likely that the diisocyanate present in some polygeline batches is the histamine-releasing substance. Better purification of polygeline and pretreatment with histamine H1-receptor and H2-receptor antagonists have both substantially reduced the frequency of clinical reactions. Changes in plasma complement levels have been observed in patients with anaphylactoid reactions to HES. Antibodies against HES have been detected in humans, but no correlation has been found between the titer of antibodies and anaphylactoid reactions to HES. A further problem with repeated HES infusions is its potentially irreversible storage. Anaphylactoid reactions to colloids should be treated according to the grade of severity. Epinephrine should only be given in severe (grades III and IV) reactions. The early application of glucocorticosteroids (500-1,000 mg of prednisolone equivalent) also may be helpful.

5-lipoxygenase-derived products of arachidonic acid are implicated in the pathophysiology of psoriasis, a common hyperproliferative and inflammatory skin disease. We therefore examined whether there is an activation of this enzymatic pathway in extracutaneous tissues. For this purpose, we measured the conversion of 14C-arachidonic acid by polymorphonuclear leukocytes from psoriatic patients and controls. No significant difference in the generation of leukotriene B4 and 5-hydroxyeicosatetraenoic acid by polymorphonuclear leukocytes was noted between the two groups. We conclude that in psoriasis there is no enhanced activity of the 5-lipoxygenase pathway in circulating polymorphonuclear leukocytes.