The final destiny of acantholytic cells in pemphigus is Fas mediated

BACKGROUND

Pemphigus is an autoimmune disease characterized by the formation of intra-epidermal blisters. Patients develop auto-antibodies against desmoglein 1 and 3 proteins and induce acantholysis.

OBJECTIVE

This work addresses the issue of whether the Fas pathway mediates acantholysis. Furthermore, the possible suppliers of the Fas pathway were investigated.

METHODS

Seventeen biopsies of pemphigus patients were studied by haematoxylin and eosin staining, and apoptosis was defined by TUNEL. The expression of Fas, FasL and caspase 3 was studied by in situ hybridization and immunohistochemistry. Cell infiltrates were studied by immunofluorescence with monoclonal anti-CD3, CD4, CD8, CD19 and CD69.

RESULTS

All of the biopsies showed intra-epidermal blisters, acantholytic cells and inflammatory infiltrates. The blisters expressed Fas, FasL and caspase 3. Cell infiltrates were composed of CD8 and a few CD4(+)CD69(+) cells. Additionally, CD19(+) cells were detected. Interestingly, the Fas expression was increased in acantholytic cells and perilesional keratinocytes. Incidentally, these cells exhibited apoptotic features. Interestingly, the CD8 cells expressed FasL.

CONCLUSION

This paper presents the morphological evidence that apoptosis and acantholysis are linked. Therefore, the Fas pathway is associated with CD8 cells in pemphigus lesions.

HLA-DRB1*0101 is associated with the genetic susceptibility to develop lichen planus in the Mexican Mestizo population

The etiology of lichen planus (LP) is still unknown and previous studies have found an association between LP and HLA-DR1, DR2, DR3, DR9 and DR10 in different populations. The aim of this study was to analyze the distribution of the HLA-DRB1 alleles in Mexican Mestizo patients with LP. The aim of this study was to determine the gene frequency of HLA-DR locus in Mexican Mestizo patients with LP. We studied 20 patients with LP and 99 healthy Mexican Mestizo controls. HLA-DRB1 was performed by PCR-SSO reverse dot blot hybridization. High resolution HLA typing was performed by PCR-SSP. The HLA-DRB1*0101 allele was associated significantly in LP patients compared with healthy controls (pC = 0.0007, OR = 5.46, 95% CI = 1.86-16.06). HLA-DRB1*0101 is a marker for the development of LP in Mexican Mestizo population, yet another gene or HLA marker within MHC region may be the causatively associated gene.

Effectors of inflammation in actinic prurigo

BACKGROUND

Actinic prurigo is a specific familial photodermatosis of uncertain pathogenesis.

OBJECTIVE

Our purpose was to investigate the immunohistologic presentation of actinic prurigo to explore the involved pathomechanisms.

METHODS

The present immunohistochemical study was performed on biopsy specimens from 20 Mexican patients presenting with a severe and perennial form of the disease.

RESULTS

The dense inflammatory infiltrate was composed predominantly of helper T type 1 lymphocytes admixed with scattered B-cell lymphoid follicles and numerous dermal dendrocytes. Keratinocytes contained abundant tumor necrosis factor-alpha and calprotectin.

CONCLUSION

In subjects genetically predisposed to actinic prurigo, ultraviolet light may trigger excessive tumor necrosis factor-alpha production by keratinocytes whose sustained release in turn exerts its proinflammatory activity and deleterious epidermal effects. Such a cascade of events is in line with the therapeutic benefit already reported when thalidomide is used to treat actinic prurigo.

TNFalpha and IL-6 are mediators in the blistering process of pemphigus

BACKGROUND

Pemphigus is an autoimmune disease characterized by intraepidermal blisters induced by pemphigus IgG. In addition to autoantibodies, molecular mechanisms involved in acantholysis remain largely unknown. For this reason, we address a possible role of the inflammatory cytokines IL-6 and TNFalpha in pemphigus lesions.

METHODS

Sixteen biopsies from patients with different types of pemphigus were studied by in situ hybridization using DNA fluorescent probes for IL-6 and TNFalpha mRNA.

RESULTS

Fifty-six percent of lesional biopsies exhibited cytokine gene expression, which was poorly expressed in noninvolved skin. Deposits of TNFalpha and IL-6 were products of in situ transcription at the epidermal level.

CONCLUSIONS

Inflammatory cytokine expression around the blister could play a mediator role in pemphigus lesions by increasing epithelial damage.

Cytodiagnosis of cutaneous basal and squamous cell carcinoma

OBJECTIVE

We performed a prospective study to evaluate the diagnostic accuracy of cytologic examination in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), in order to assess its clinical value. Study design Samples were taken by the "scraping" technique which involves scraping with a scalpel blade directly over the skin tumor surface, smearing the cells onto several glass slides, and fixing them with "citospray." The specimens were stained with the Papanicolaou stain. Punch biopsies were taken to confirm the clinical and cytologic impression.

RESULTS

We collected 45 skin tumors in total, clinically presumed to be either BCC (n = 15) or SCC (n = 30). Imprint cytology demonstrated to be of help in the rapid diagnosis of skin tumors.

CONCLUSIONS

Cytologic examination is easy to perform, saves time, provides a rapid diagnosis, and can be considered, under experienced hands, reliable in the confirmation of malignant skin tumors. Cytology does not give much information about tumor patterns or subtypes which can be related to aggressive behavior and can be very important in further therapeutic decisions. Therefore, histopathologic confirmation is mandatory before any therapeutic maneuver.

Further evidence of the role of HLA-DR4 in the genetic susceptibility to actinic prurigo

BACKGROUND

Actinic prurigo (AP) is triggered by sun exposure. Its prevalence in Mexicans seems to be particularly high, which suggests a genetic susceptibility.

OBJECTIVE

Our purpose was to determine the role of major histocompatibility complex (MHC) genes in the genetic susceptibility to AP.

METHODS

Fifty-six Mexican Mestizo patients with AP underwent serologic typing for HLA class I and class II antigens. Class II MHC genes were also studied by DNA analysis. Findings in patients were compared with 100 ethnically matched healthy controls.

RESULTS

We found that 92.8% of patients with AP were HLA-DR4 positive (corrected p = 0.002; odds ratio [OR] = 10.1). The class I antigens HLA-A28 and HLA-B39 (B16) were also significantly increased (p < or = 0.000001, OR = 20.9 and p = 0.0001, OR = 6.7, respectively) compared with normal controls. Allele-specific oligonucleotide DR4 subtyping showed that 80.7% of HLA-DR4+ patients with AP were also positive for the DRB1*0407 allele.

CONCLUSION

These results confirm the role of HLA-DR4 (DRB1*0407) in the genetic susceptibility to AP and raise the possibility of a role for class I MHC antigens HLA-A28 and B16 in Mexican patients.

Pigmentary problems in the tropics

Pigmentary problems are one of the most frequent causes of dermatologic consultation in the tropics. This article deals with diseases seen mostly in tropical countries (ashy dermatosis, lichen planus pigmentosus, frictional dermatitis, pityriasis versicolor, and pinta) and in which a combination of racial, ecologic, nutritional, and social factors all contribute. Other common dermatoses seen worldwide, such as vitiligo and melasma, sometimes acquire dramatic expressions in tropical countries, and their management is usually difficult even for the most experienced dermatologists.

[Becker's melanosis: a case report]

Becker melanosis is a dermatosis characterized by hyperpigmentation and hypertrichosis in absence of cells nevus; its frequency is unknown an its presentation is rare in the infancy; appearance usually during puberty. In the last years its association to anomalies of development increase the importance of this entity. We present the case of 4 years old girl considered the youngest report in the literature, with affection of trunk and right leg associated to minimum shorten of right leg.