Psoriasis vulgaris and human leukocyte antigens

BACKGROUND

Psoriasis vulgaris is a skin disease with a complex immunological and genetic background, triggered by environmental factors. The association of human leukocyte antigens (HLA) and psoriasis has long been reported on population and familial studies.

OBJECTIVES

To review and discuss studies on psoriasis vulgaris and HLA, in Caucasian and non-Caucasian populations.

METHODS

The major population studies on psoriasis vulgaris and the associated HLA antigens and alleles are described and discussed based on a review of the current literature.

RESULTS

Population studies demonstrate the presence of different HLA specificities as well as extended haplotypes in patients with psoriasis, when compared to controls. Some alleles occur in a lower frequency in patients with psoriasis, indicating they could be protection alleles. In all studies which HLA class I was typed, Cw6 or Cw*0602 was present in a significant frequency in patients with psoriasis, mainly when early onset and positive family history were considered. HLA-DRB1*0701 was also present in a higher frequency in patients in different populations.

CONCLUSIONS

Different antigens and alleles from both HLA classes I and II were seen in a significantly higher frequency in patients with psoriasis vulgaris. HLA Cw*0602 and DRB1*0701 were represented in different reports, and the former was related mainly to psoriasis type I.

HLA markers in familial Lichen sclerosus

BACKGROUND

Lichen sclerosus (LS) has been identified with increased frequency in families,often associated with HLA markers, mainly DQ7. A genetic co-etiology seems likely in this setting. Moreover, there is an association of LS with autoimmune disorders, such as the presence of anti-thyroid peroxidase autoantibodies (anti-TPO), a hallmark of autoimmune thyroid diseases.

PATIENTS AND METHODS

In 3 families affected by LS, we verified their HLA markers, and identified previously undiagnosed cases of LS and autoimmune disorders. 30 individuals were examined with history, skin biopsy, HLA class I and II typing by PCR-SSP, and measurement of anti-TPO, free thyroxine and thyroidstimulating hormones (TSH) levels.

RESULTS

There were 8 cases of LS, 50 % of them anti-TPO+. Autoimmune disorders were found in 40 % (total) and in 87.5 % of those affected. Most common HLA markers were B*15, B*57, CW*03, CW*07, CW*18, DRB1*04, DRB1*07, DRB4*. The three latter have been previously associated with LS.

CONCLUSION

New cases of LS and autoimmune disorders can be detected in first degree relatives of patients with LS. The presence of anti-TPO antibodies strongly suggests autoimmune thyroiditis. There is intra-familial association between the haplotype HLA-B*15 -DRB1*04 -DRB4* and anti-TPO,emphasizing their link with thyroiditis. New familial approaches might help to make clear the pathogenesis of LS and its association with autoimmune diseases.

Correlation between HLA and pityriasis rosea susceptibility in Brazilian blacks

OBJECTIVES

The human leucocyte antigen (HLA) has been related to susceptibility factors in several diseases. This study aimed to determine the potential genetic susceptibility of patients with pityriasis rosea (PR) through HLA molecular typing analysis.

METHODS

The method of choice was polymerase chain reaction with sequence-specific primers (PCR-SSP) using low-resolution typing kits, with determination of the alleles class I (HLA-A, HLA-B and HLA-C) and class II (HLA-DRB1, DRB3, DRB4, DRB5 and DQB1) performed in 30 Afro-Brazilian PR-diagnosed patients and 45 healthy individuals as the control group (PR-C).

RESULTS

Analysis of the HLA typing results showed that the relative risk (RR) of 4.00 [95% confidence interval (95% CI) 1.20-13.28, two-tailed P = 0.018] for allele HLA-DQB1*04 class II, detected in 33.3% of PR patients, was significant. By contrast, in the control group only 11.1% of subjects had that allele. Three out of six B*51 alleles and three out of six B*53 alleles detected in PR patients were found, together with the allele DQB1*04.

CONCLUSION

We suggest that alleles DQB1*04 may be involved in the genetic susceptibility of PR based on the significant predominance of those alleles observed in the black PR patients. We also recommend that more studies are conducted on populations of other ethnic origins, preferentially with higher resolution techniques of DNA typing.

Manifestações tegumentares da doença enxerto contra hospedeiro em pacientes transplantados de medula óssea

A doença enxerto contra hospedeiro (DECH) é uma síndrome sistêmica que ocorre em pacientes que recebem linfócitos imunocompetentes. A fisiopatologia envolve uma reação imunológica entre linfócitos transplantados e tecidos do hospedeiro, e ocorre por ataque imune das células T do doador às células do hospedeiro, as quais diferem daquelas pelos antígenos de histocompatibilidade. É, assim, uma complicação primária do transplante de medula óssea (TMO) alogênico. O envolvimento cutâneo é freqüente na DECH e contribui para a morbidade e mortalidade do TMO. O dermatologista tem papel importante na avaliação dos pacientes auxiliando no reconhecimento precoce da DECH e suas complicações e no acompanhamento clínico desses pacientes. Nesta revisão os autores enfatizam as manifestações cutâneas da DECH, tendo como base sua experiência pessoal no acompanhamento de pacientes portadores de DECH transplantados de medula óssea no Centro Nacional de Transplante de Medula Óssea/Inca/MS, no Rio de Janeiro, nos últimos 14 anos.

A morphological and cytochemical study of the interaction between Paracoccidiodes brasiliensis and neutrophils

Paracoccidioidomycosis is a systemic granulomatous disease caused by the dimorphic fungus Paracoccidioides brasiliensis. It is the most prevalent systemic mycosis of Latin America and 80% of the reported cases are from Brazil. Because of the great number of neutrophils found in the P. brasiliensis granuloma, studies have been done to evaluate the role of these cells during the development of the infection. Scanning and transmission electron microscopy of thin sections showed that the neutrophils ingest yeast cells through a typical phagocytic process with the formation of pseudopodes. The pseudopodes even disrupt the connection established between the mother and the bud cells. Neutrophils also associate to each other, forming a kind of extracellular vacuole where large yeast cells are encapsulated. Cytochemical studies showed that once P. brasiliensis attaches to the neutrophil surface, it triggers a respiratory burst with release of oxygen-derived products. Attachment also triggers neutrophils degranulation, with release of endogenous peroxidase localized in cytoplasmic granules. Together, these processes lead to killing of both ingested and extracellular P. brasiliensis.

Comparative biochemistry of human skin: glycosaminoglycans from different body sites in normal subjects and in patients with localized scleroderma

OBJECTIVES

The aim of this investigation is to compare the relative proportions of disaccharides of chondroitinase-digestible glycosaminoglycans (GAGs) among the different body sites in control human skin and in the skin lesions of patients with localized scleroderma.

METHODS

The disaccharide relative proportions were determined using high-performance liquid chromatography (HPLC).

RESULTS

DeltaDi-4S, the main disaccharide unit of dermatan sulphate (DS), was the major skin GAG disaccharide (approximately 70% of the total) in control skin among all different body sites studied here. In scleroderma there was an increase in the relative proportion of both deltaDi-HA, the main disaccharide unit of hyaluronic acid (HA), and deltaDi-diS(B) (alpha-deltaUA(2SO4)-1-->3-GalNAc(4SO4)), derived from DS, and a decrease in deltaDi-4S, as compared with the uninvolved skin or the site-matched control skin.

CONCLUSION

DS is the major GAG species in normal skin from different body sites. In addition, our results suggest a decrease and also a structural change in DS and an increase in the proportion of HA in scleroderma skin.

Type I and type III collagens in cutaneous mucinosis

Cutaneous mucinoses are a heterogeneous group of diseases characterized by the focal or diffuse dermal deposition of glycosaminoglycans. The histopathologic examination of many cutaneous mucinoses reveals that the collagen fibers are fragmented. We wanted to characterize the type I (COL1) and type III (COL3) collagen distribution in skin biopsy specimens of patients with cutaneous mucinosis. The diagnosis of mucinosis was based on a modification of the classification by Rongioletti and Rebora: four patients had familial papulonodular mucinosis: four had papular mucinosis, one of which was associated with myxedema and one had scleromyxedema; and one had focal mucinosis. We performed anti-type I and type III collagens immunolabeling on frozen sections. Immunofluorescence for COL1 was increased in the superficial dermis of 2/4 familial papulonodular mucinosis, in 5/5 of papular mucinosis, and in scleromyxedema and focal mucinosis cases. The mid-dermis showed intense staining for COL1 at the periphery of collagen bundles and, in three cases of familial papulonodular mucinosis and two cases of papular mucinosis, a lacy appearance. The superficial dermis of familial papulonodular mucinosis specimens and of papular mucinosis + myxedema, scleromyxedema, and focal mucinosis specimens had decreased COL3 staining. The mid-dermis showed a more prominent fibrillar staining at the periphery of the collagen bundles, and two cases of papular mucinosis showed intense labeling for COL3. Both COL1 and COL3 distributions are altered in cutaneous mucinosis. An intense labeling with COL1 is predominantly found in the superficial layer of cutaneous mucinosis. Cases of FTP revealed decreased COL3 reactivity at the superficial layer.