iRHOM2: A Regulator of Palmoplantar Biology, Inflammation, and Viral Susceptibility.

The palmoplantar epidermis is a specialized area of the skin that undergoes high levels of mechanical stress. The palmoplantar keratinization and esophageal cancer syndrome, tylosis with esophageal cancer, is linked to mutations in RHBDF2 encoding the proteolytically inactive rhomboid protein, iRhom2. Subsequently, iRhom2 was found to affect palmoplantar thickening to modulate the stress keratin response and to mediate context-dependent stress pathways by p63. iRhom2 is also a direct regulator of the sheddase, ADAM17, and the antiviral adaptor protein, stimulator of IFN genes. In this perspective, the pleiotropic functions of iRhom2 are discussed with respect to the skin, inflammation, and the antiviral response.

Abnormal keratinization and cutaneous inflammation in Mal de Meleda.

Mal de Meleda (MDM) is a rare, autosomal recessive form of palmoplantar keratoderma due to mutations in the gene, encoding for secreted lymphocyte antigen 6/urokinase-type plasminogen activator receptor related protein 1 (SLURP1). We report a four-year-old Taiwanese MDM female case whose biopsy specimen of hyperkeratotic lesions showed abnormal keratinization and cutaneous inflammation with characteristic transmission electron microscopic (TEM) findings and immunostaining results. The patient presented with pruritic and severely hyperkeratotic plaques on the bilateral palms and soles whichwere fringed with erythematous scaly areas. A homozygous c.256 G>A mutation, predicting a conversion of p.Gly86Arg, in SLURP1gene was detected. Histopathological examinations showed marked hyperkeratosis, acanthosis and hypergranulosis in the epidermis, accompanied by perivascular lymphocytic infiltrates in the dermis. The whole layers of the epidermis and perivascular infiltrates of the dermis were stained positive with anti-tumor necrosis factor alpha (TNFα) antibody in the biopsy specimen from the sole and the ankle. TEM examination of the biopsy specimen from the plantar hyperkeratotic plaque showed various-sized vacuoles surrounding nuclei of many keratinocytes in the spinous layer. In addition, there were numerous irregular keratohyaline granules in the granular layer. Several microorganisms and many lipid-like droplets were found in the thickened cornified layer. SLURP1 protein is known as a marker of late differentiation, predominantly expressed in the granular layer, and also known to have an inhibitory effect on TNFα release. Our results exhibited excessive TNFα expression in keratinocytes and perivascular infiltrates of the dermis, and several characteristic morphological observations of keratinocytes in MDM.

Association of Transient Palmoplantar Keratoderma With Clinical and Immunologic Characteristics of Bullous Pemphigoid.

Importance: Development of transient palmoplantar keratoderma (PPK) with bullous pemphigoid (BP) has only been described in 2 isolated case reports. The clinical significance and the pathophysiologic mechanisms of this association are unknown. Objective: To examine the clinical characteristics and immunological profile of patients with BP who develop transient PPK and analyze therapeutic options and outcomes. Design, Setting, and Participants: In this case series, patients with BP who developed acquired, transient PPK, and were treated at a single institution from January 1, 2015, through December 31, 2017, were studied. Main Outcomes and Measures: Clinical and immunological activity of BP, treatment administrated before and after PPK appearance, and patient outcomes. Results: Six patients with BP and transient PPK were identified and included in the study. There were 5 women and 1 man with a mean age of 72 years. At baseline, all patients had a generalized, multibullous BP and high serum anti-BP180 antibodies (mean, 130 U/mL; range, 73-150), whereas anti-BP230 antibodies were elevated in only 1 case. The PPK appeared a mean 6.2 (range, 2-12) months after BP diagnosis, following a prolonged period of disease activity with recurrent flares. When the PPK occurred, BP was uncontrolled on therapy (mean Bullous Pemphigoid Disease Activity Index [BPDAI] score, 57; range, 34-105; mean anti-BP180 antibodies titer, 122 U/mL; range, 81-150). On administration of additional systemic immunosuppressive therapies, the PPK healed progressively in a mean 4.3 months (range, 2-9), along with BP clinical remission in 4 of 6 patients. No relationship was found between PPK occurrence and anti-BP180/230 antibodies profiles. In contrast, blister fluids collected at the time of PPK displayed a much higher level of interleukin 1ß (IL-1ß) compared with those collected in the absence of PKK. Expression of IL-17A, IL-17F, and IL-22 was also enhanced in the blister fluid of patients with BP who had PPK. Conclusions and Relevance: To our knowledge, this is the first report of 6 cases of BP with transient PPK with extensive immunological investigation. The PPK appeared after a prolonged period of clinical BP activity punctuated with recurrent relapses, was transient, and healed after BP control with additional immunosuppressive therapy. Enhanced expression of a particular cytokine panel in the blister fluid at time of PPK could support keratinocyte proliferation as described in patients with psoriasis. Transient PPK could represent a clinical marker of severe, treatment-resistant BP.

Bullous pemphigoid with hyperkeratosis and palmoplantar keratoderma: Three cases.

The clinical features of bullous pemphigoid are extremely polymorphous. Several atypical forms of bullous pemphigoid have been described, and the diagnosis critically relies on immunopathological findings. We describe three bullous pemphigoid patients characterized by palmoplantar keratoderma, diffused hyperkeratotic cutaneous lesions and extremely high levels of immunoglobulin E serum. The diagnosis of bullous pemphigoid should be taken into account in patients presenting diffused hyperkeratotic cutaneous lesions and palmoplantar keratoderma, even in the absence of blisters. Alteration of the keratinization process, that could occur in patients with genetic mutations in desmosomal and hemidesmosomal genes, may also be due to circulating autoantibodies against hemidesmosomal proteins in these bullous pemphigoid patients.

Keratoderma-like T cell dyscrasia: A report of 13 cases and its distinction from mycosis fungoides palmaris et plantaris.

BACKGROUND: Atypical epitheliotropic T cell lymphocytic infiltrates are commonly encountered in routine and consultative dermatopathology practices and typically do not represent mycosis fungoides. Other conditions can mimic certain light microscopic and phenotypic findings encountered in mycosis fungoides, comprising a diverse spectrum of conditions including the lymphomatoid drug reaction, collagen vascular disease, viral hypersensitivity reactions and cutaneous T cell dyscrasia. AIMS: To examine biopsies obtained from cutaneous T cell dyscrasia localized to the palms and soles and to evaluate whether it exhibits a morphologic and pathogenetic continuum with mycosis fungoides plantaris et palmaris. METHODS: We examined 13 biopsies showing an epidermotropic superficial lymphocytic infiltrate from thirteen patients who presented with a palmar and/or plantar keratoderma without other sites of cutaneous involvement. Conventional light microscopy, immunophenotyping and clonality studies were carried out. The clinical features were recorded. RESULTS: Biopsies showed a variably dense, superficial, angiocentric CD4 or CD8 dominant lymphocytic infiltrate accompanied by a non-destructive pattern of epidermotropism. Low-grade cerebriform atypia along with variable diminution in the expression of CD7 and CD62L was noted. In three cases, statins were suspected to be the cause. Due to lack of familiarity with the entity, treatment interventions were inconsistent and not aggressively pursued. There was no evidence of disease progression to mycosis fungoides in any case. LIMITATIONS: The limitations of this study include the lack of long-term follow up and information on the nature of the therapeutic interventions and responses to treatment. CONCLUSION: The spectrum of cutaneous lymphoid dyscrasias should be expanded to include cases manifesting as palmo-plantar keratoderma. These cases are to be distinguished from mycosis fungoides palmaris et plantaris. As with other forms of cutaneous lymphoid dyscrasia, the lesions tend to be persistent. The course however, is indolent in most cases.

Olmsted syndrome: exploration of the immunological phenotype.

BACKGROUND: Olmsted syndrome is a rare congenital skin disorder presenting with periorifical hyperkeratotic lesions and mutilating palmoplantar keratoderma, which is often associated with infections of the keratotic area. A recent study identified de novo mutations causing constitutive activation of TRPV3 as a cause of the keratotic manifestations of Olmsted syndrome. METHODS: Genetic, clinical and immunological profiling was performed on a case study patient with the clinical diagnosis of Olmsted syndrome. RESULTS: The patient was found to harbour a previously undescribed 1718G-C transversion in TRPV3, causing a G573A point mutation. In depth clinical and immunological analysis found multiple indicators of immune dysregulation, including frequent dermal infections, inflammatory infiltrate in the affected skin, hyper IgE production and elevated follicular T cells and eosinophils in the peripheral blood. CONCLUSIONS: These results provide the first comprehensive assessment of the immunological features of Olmsted syndrome. The systemic phenotype of hyper IgE and persistent eosinophilia suggest a primary or secondary role of immunological processes in the pathogenesis of Olmsted syndrome, and have important clinical consequences with regard to the treatment of Olmsted syndrome patients.

SLURP1 mutation-impaired T-cell activation in a family with mal de Meleda.

BACKGROUND: Mal de Meleda (MDM) is palmoplantar erythrokeratoderma with an autosomal recessive inheritance and is caused by a mutation in the gene encoding SLURP-1 (lymphocyte antigen 6/urokinase-type plasminogen activator receptor related protein-1). SLURP-1 is an allosteric agonist to the nicotinic acetylcholine receptor (nAchR) and it regulates epidermal homeostasis. In addition, murine studies have shown that nAchR signalling is important for the regulation of T-cell function. Among the family members, patients with the homozygous SLURP1 (previously known as ARS component B) mutation are prone to melanoma and viral infection, which might link to defective T-cell function as well as a derangement of epidermal homeostasis. OBJECTIVES: To investigate the association of the SLURP1 gene mutation with T-cell activation in a Taiwanese family with MDM. To test that SLURP-1 is essential for T-cell activation. METHODS: Human peripheral blood mononuclear cells (PBMCs) were isolated from a Taiwanese MDM family bearing the G to A substitution in nucleotide 256 in the SLURP1 gene, corresponding to a glycine to arginine substitution at amino acid 86 (G86R) in the SLURP-1 protein. PBMCs from homozygotes and wild-type controls were stimulated with anti-CD3/anti-CD28 antibodies and the level of T-cell activation was determined by the stimulation index. RESULTS: PBMCs with the heterozygous and homozygous SLURP-1 G86R mutation had defective T-cell activation. This was restored by the addition of 0·5 µg mL(-1) recombinant human SLURP-1 protein. CONCLUSIONS: Patients with MDM with the homozygous SLURP-1 G86R mutation may have an impaired T-cell activation. The presence of wild-type SLURP-1 is essential for normal T-cell activation.

Anti-Ro52 antibodies, antisynthetase antibodies, and antisynthetase syndrome.

We present a case of antisynthetase syndrome manifesting with interstitial lung disease, mechanic's hands, nailfold abnormalities, and subclinical myositis, in the presence of antibodies to the aminoacyl tRNA synthetase PL-12 and also to Ro52. Antibodies to Ro52 have been recently associated with idiopathic inflammatory myositis, but there have only been occasional reports of this antibody occurring in association with aminoacyl tRNA synthetases, including PL-12. Our case adds to the descriptions of the concurrence of antibodies to PL-12 and Ro52. The mechanism for the coupling of antibody response remains elusive but is likely to play a fundamental role in disease pathogenesis.

Huriez syndrome: case report with a detailed analysis of skin dendritic cells.

We report a 60-year-old man with familial scleroatrophic syndrome of Huriez who developed squamous cell carcinomas on the affected skin of the right palm. Immunohistochemical analysis showed a marked reduction in the number of CD1a+, Lag+ and S100+ epidermal Langerhans cells, but not of CD1b+ and factor XIIIa+ dermal dendritic cells, limited to palmoplantar skin. The Langerhans cell depletion was not associated with an abnormal skin content of mRNA for factors involved in Langerhans cell development or recruitment in the epidermis, including granulocyte/macrophage colony-stimulating factor, transforming growth factor-beta1 and macrophage inflammatory protein-3alpha. The results indicate that other as yet unknown mechanisms may account for the reduced number of Langerhans cells in the affected skin of such patients.

Hereditary palmoplantar keratoderma and dermatophytosis in the northernmost county of Sweden (Norrbotten).

Clinical reports of hereditary palmoplantar keratoderma are generally based on a limited number of patients. In 1967 the prevalence in the northernmost county of Sweden (Norrbotten) was shown to be 0.55%. In 1982 it was possible to trace half of the original propositi from that study. Among these families, a severe clinical form with a presumed recessive inheritance could be distinguished. The clinical pictures in relatives of the original propositi were described, and other diseases were listed together with those in patients from previously performed studies. The frequency of dermatophytosis was 36.2%, which was equal to a prevalence of 37.6%. T. mentagrophytes occurred significantly more often and immunological factors, such as increased presence of blood group A, specific dermatophyte IgG antibodies, precipitating antibodies and an immunological in vitro reaction to keratin, supported differences in the distribution of dermatophytes. However, the amount of keratin was considered the most important factor for the affinity of dermatophytes to the palms and soles. A vesicular eruption along the hyperkeratotic border and a mononuclear cell infiltrate were often reported. Such reactions were interpreted as immunological reactions to dermatophytosis. Scaling and fissuring were considered clinical signs of dermatophyte infections and not a part of the originally reported clinical picture. Results of the histopathological study corresponded to previously reported descriptions of the Unna-Thost variety. However, it has recently been reported that the histopathological picture of this variety was based on histopathological features of epidermolytic palmoplantar keratoderma. The existence on the Continent of the Unna-Thost variety was therefore questioned. Histopathological features of epidermolytic palmoplantar keratoderma were not found in the County of Norrbotten and the designation "Diffuse HPPK type Norrbotten" has therefore been proposed. The histopathological picture of the presumed recessive variety did not differ from that of the dominant variety but ultrastructural characteristics differentiated it from Mal de Meleda and the dominant variety. It was therefore concluded that a new variety with a presumed recessive inheritance was found.

Punctate palmoplantar keratoderma associated with morbus Bechterew and HLA B 27. A family study.

Four patients in a family with punctate palmoplantar keratoderma (Buschke-Fischer) associated with Morbus Bechterew and HLA B 27 in 3 of the family members are reported. Without severe side effect, the proband was successfully treated with 50 mg etretinate per day for 6 weeks.

Immunological alterations in a case of Papillon-Lefèvre syndrome with recurrent cutaneous infections.

An immunological study was performed in a 16-year-old boy affected with Papillon-Lefèvre syndrome (PLS) and recurrent staphylococcal cutaneous infections. A defect of neutrophil intracellular killing of Staphylococcus aureus and a decreased lymphocyte proliferative response to phytohaemagglutinin were detected. The possible role of these alterations in promoting recurrent infections in PLS is discussed.

Report of a family with mal de Meleda in Taiwan: a clinical, histopathological and immunological study.

A family in Taiwan is reported to have Mal de Meleda with possibly autosomal recessive inheritance among 5 of its members. The glove- and sock-like erythrokeratosis and the hyperkeratotic plaques of the knees and elbows are the common features. Erythema of the nose, cheeks, and the perioral area in 4 affected members, actinic elastosis in 2 severely affected members, and partially impaired cell-mediated immunity in vitro in both affected and unaffected members are notable findings. Tigason (etretinate) treatment was beneficial in regard to hyperkeratinization, but not to erythema.

The Papillon-Lefèvre syndrome: neutrophil dysfunction with severe periodontal disease.

Two cases of Papillon-LeF evre are described. Both siblings demonstrated neutrophil dysfunction and severe precocious periodontal disease. The neutrophil locomotion defect was characterized by a decreased migration toward a chemotactic factor and decreased random migration. Binding of the chemotactic factor, FMLP, to the neutrophil surface was unchanged. Both patients harbored Actinobacillus actinomycetemcomitans and showed elevated serum IgG levels. Both patients also demonstrated salivary and serum antibody to A. actinomycetemcomitans. The Papillon-LeF evre syndrome is compared with the more common localized juvenile periodontitis.