Enno Christophers

A peptide antibiotic from human skin

To avoid opportunistic infections, plants and animals have developed antimicrobial peptides in their epithelia that can form pores in the cytoplasmic membrane of microorganisms. After contact with microorganisms, vertebrate skin, trachea and tongue epithelia are rich sources of peptide antibiotics, which may explain the unexpected resistance of these tissues to infection. Here we report that human skin is protected in a similar way by an inducible, transcriptionally regulated, antibiotic peptide, which resembles those in other mammals.

Psoriasis of early and late onset: Characterization of two types of psoriasis vulgaris

In 2,147 patients suffering from psoriasis, evaluation of the age of onset revealed two peaks, one occurring at the age of 16 years (female) or 22 years (males) and a second peak at the age of 60 years (female) or 57 years (males). Human lymphocyte antigen (HLA) tissue typing in 112 randomly assigned patients showed that HLA-Cw6, known to be at disequilibrium in psoriasis, is present in 85.3% of patients with early onset. In contrast, 14.7% patients with late onset showed this marker. Parents (father or mother) were affected in approximately half of the patients with early onset and in none belonging to the group with late onset. Furthermore, psoriasis in patients with early onset follows an irregular course and shows a strong tendency to become generalized. On the basis of clearly defined criteria (e.g., age of onset, heritability, and clinical course of disease), nonpustular psoriasis shows two distinct forms, one of which is hereditary, with early onset, and the other is sporadic and occurs in older age.

Disease concomitance in psoriasis

BACKGROUND Psoriasis is a multifactorial disease of unknown origin. OBJECTIVE Our purpose was to determine the frequency of skin disorders concomitantly seen in patients with psoriasis. METHODS We analyzed data from more than 40,000 patients and calculated sex- and age-adjusted ratios of expected and observed incidence rates of associated disorders. RESULTS The results demonstrate that, compared with age-matched control patients without psoriasis, cutaneous immune disorders such as allergic contact dermatitis, atopic dermatitis, and urticaria are underrepresented in patients with psoriasis. In contrast, certain systemic disorders such as diabetes, heart insufficiency, and obesity occur significantly more often in patients with psoriasis than in control subjects. Increased resistance to cutaneous bacterial infections was noted only in patients with early-onset psoriasis. CONCLUSION Our observations show that a distinct pattern of associated diseases exists in patients with psoriasis. Although systemic disorders such as obesity, diabetes, and heart disease may be related to dietary habits and nutritional status, the relative resistance to cutaneous infections together with decreased immune responsiveness suggest a genetically determined selection.

Psoriasis − epidemiology and clinical spectrum

Despite psoriasis being a common skin disease, there are still a number of unanswered questions. One of these is the prevalence of the disease, as there is a lack of specific data, with the majority of studies reporting estimates only. Population based studies are rare and longitudinal observations on changing prevalence rates are lacking. This contrasts with other T‐cell mediated autoimmune diseases where the number of those affected is rising.

Antimicrobial psoriasin (S100A7) protects human skin from Escherichia coli infection

Human healthy skin is continuously exposed to bacteria, but is particularly resistant to the common gut bacterium Escherichia coli. We show here that keratinocytes secrete, as the main E. coli–killing compound, the S100 protein psoriasin in vitro and in vivo in a site-dependent way. In vivo treatment of human skin with antibodies to psoriasin inhibited its E. coli–killing properties. Psoriasin was induced in keratinocytes in vitro and in vivo by E. coli, indicating that its focal expression in skin may derive from local microbial induction. Zn2+-saturated psoriasin showed diminished antimicrobial activity, suggesting that Zn2+ sequestration could be a possible antimicrobial mechanism. Thus, psoriasin may be key to the resistance of skin against E. coli.

Sequence and Haplotype Analysis Supports HLA-C as the Psoriasis Susceptibility 1 Gene

Previous studies have narrowed the interval containing PSORS1, the psoriasis-susceptibility locus in the major histocompatibility complex (MHC), to an approximately 300-kb region containing HLA-C and at least 10 other genes. In an effort to identify the PSORS1 gene, we cloned and completely sequenced this region from both chromosomes of five individuals. Two of the sequenced haplotypes were associated with psoriasis (risk), and the other eight were clearly unassociated (nonrisk). Comparison of sequence of the two risk haplotypes identified a 298-kb region of homology, extending from just telomeric of HLA-B to the HCG22 gene, which was flanked by clearly nonhomologous regions. Similar haplotypes cloned from unrelated individuals had nearly identical sequence. Combinatorial analysis of exonic variations in the known genes of the candidate interval revealed that HCG27, PSORS1C3, OTF3, TCF19, HCR, STG, and HCG22 bore no alleles unique to risk haplotypes among the 10 sequenced haplotypes. SPR1 and SEEK1 both had messenger RNA alleles specific to risk haplotypes, but only HLA-C and CDSN yielded protein alleles unique to risk. The risk alleles of HLA-C and CDSN (HLA-Cw6 and CDSN*TTC) were genotyped in 678 families with early-onset psoriasis; 620 of these families were also typed for 34 microsatellite markers spanning the PSORS1 interval. Recombinant haplotypes retaining HLA-Cw6 but lacking CDSN*TTC were significantly associated with psoriasis, whereas recombinants retaining CDSN*TTC but lacking HLA-Cw6 were not associated, despite good statistical power. By grouping recombinants with similar breakpoints, the most telomeric quarter of the 298-kb candidate interval could be excluded with high confidence. These results strongly suggest that HLA-Cw6 is the PSORS1 risk allele that confers susceptibility to early-onset psoriasis.

Interleukin-4 therapy of psoriasis induces Th2 responses and improves human autoimmune disease

Selective skewing of autoreactive interferon-γ (IFN-γ)-producing T helper cells (Th1) toward an interleukin-4 (IL-4)-producing (Th2) phenotype can in experimental animals alleviate autoimmune disease without inducing general immunosuppression. In a prospective dose escalation study, we assessed treatment with human IL-4 (rhuIL-4) in 20 patients with severe psoriasis. The therapy was well tolerated, and within six weeks all patients showed decreased clinical scores and 15 improved more than 68%. Stable reduction of clinical scores was significantly better at 0.2–0.5 μg rhuIL-4 than at ≤0.1 μg rhuIL-4 (P = 0.009). In psoriatic lesions, treatment with 0.2–0.5 μg/kg rhuIL-4 reduced the concentrations of IL-8 and IL-19, two cytokines directly involved in psoriasis; the number of chemokine receptor CCR5+ Th1 cells; and the IFN-γ/IL-4 ratio. In the circulation, 0.2–0.5 μg/kg rhuIL-4 increased the number of IL-4+CD4+ T cells two- to three-fold. Thus, IL-4 therapy can induce Th2 differentiation in human CD4+ T cells and has promise as a potential treatment for psoriasis, a prototypic Th1-associated autoimmune disease.

Epidemiology and comorbidity of psoriasis in children

Background  Psoriasis is a common disease affecting all age groups. In contrast to adult psoriasis, only few studies on the epidemiology of childhood psoriasis have been published.

ORAL 8-METHOXYPSORALEN PHOTOCHEMOTHERAPY OF PSORIASIS: The European PUVA Study: a Cooperative Study among 18 European Centres

In a multicentre study in eighteen European cities 3175 patients were treated with photochemotherapy (PUVA) for severe psoriasis and data obtained during a period of 39 months were analysed. A response better than marked improvement was obtained in 88.8% of patients; twenty exposures and a total cumulative UVA dose of 96 J/cm2 were required for clearing, the duration of the clearing phase being 5.3 weeks. A comparison of the results of this study with those of a similar multicentre study in the United States on 1300 patients and using a different treatment protocol, revealed that while treatment results and the number of individual treatment sessions were similar the European protocol requires only half the time and less than half the total cumulative UVA dose for clearing of psoriasis. When patients in the European study who received continuous maintenance treatment were compared with patients who received no maintenance treatment the probability that a patient would remain in remission for a period of 80 weeks was the same, irrespective of whether patients received maintenance treatment or not. This study confirms the dramatic efficacy of PUVA in clearing psoriasis and contains two important messages for the reduction of possible long-term hazards of this treatment. Firstly, the total UVA energy requirements for clearing psoriasis strongly depend on the treatment schedule and can be kept low if an individual approach aimed at rapid clearing of psoriasis is used. Secondly, maintenance therapy may not significantly prevent recurrences for prolonged periods of time and may thus not be necessary in most patients.

A classification of psoriasis vulgaris according to phenotype

For nearly 200 years it has been appreciated that plaque psoriasis consists of a number of distinct clinical phenotypes. However, a reliable and simple stratification of clinical presentation of psoriasis is lacking. In the era of immunogenetic association studies and an advanced understanding of the pathomechanisms of psoriasis it is important that a classification of the disease according to phenotype is readily available. Such a classification would facilitate clinically relevant interpretation of investigational data. A meeting of the International Psoriasis Council produced a consensus on clinical phenotypes of psoriasis equally relevant to clinical practitioners and psoriasis researchers.