Immunology of AIDS Related to Psoriasis

The Role of Dermatologists in the Early HIV/AIDS Epidemic: A Historical Review for the 40th Anniversary of HIV/AIDS

In 1981, the HIV/AIDS epidemic was first recognized in young gay men presenting with opportunistic infections and Kaposi sarcoma. Over the past 40 years, there has been an unparalleled and hugely successful effort on the part of physicians, scientists, public health experts, community activists, and grassroots organizations to study, treat, and prevent HIV/AIDS. Yet the role of dermatologists in the investigation of HIV/AIDS and in the treatment of infected patients has largely been neglected in the historical literature. It is important to revisit dermatologists' historic contributions and problematic biases during this epidemic and honor the legacy of the dermatologists who were instrumental in treating and advocating for patients affected by HIV/AIDS.

Diagnosing and treating psoriatic arthritis: an update

Psoriatic arthritis (PsA) is an inflammatory arthritis of uncertain pathogenesis, affecting approximately one in four patients with psoriasis. Onset of psoriasis typically precedes the development of PsA. Therefore, the dermatologist is ideally positioned to recognize the early signs and symptoms of PsA for diagnosis and subsequent treatment. The role of the dermatologist in early diagnosis and treatment is essential for preventing pain and functional disabilities, as well as the joint deterioration that accompanies progressive forms of PsA. Diagnosis of PsA is a key aspect of the clinical decision process for the dermatologist, as psoriasis plus PsA requires a different therapeutic approach from that required for psoriasis alone. Furthermore, PsA is associated with an increased risk of cardiovascular comorbidities that present significant health concerns. In this review, the pathogenesis and comorbidities of PsA are discussed. In addition, screening and imaging tools that aid in the diagnosis of PsA, as well as tools used for efficacy assessment, are reviewed. Available therapies are presented, with a focus on targeted biologics and emerging treatments.

New insights into HIV-1-primary skin disorders

Since the first reports of AIDS, skin involvement has become a burdensome stigma for seropositive patients and a challenging task for dermatologist and infectious disease specialists due to the severe and recalcitrant nature of the conditions. Dermatologic manifestations in AIDS patients act as markers of disease progression, a fact that enhances the importance of understanding their pathogenesis.

Broadly, cutaneous disorders associated with HIV type-1 infection can be classified as primary and secondary. While the pathogenesis of secondary complications, such as opportunistic infections and skin tumours, is directly correlated with a decline in the CD4⁺ T cell count, the origin of the certain manifestations primarily associated with the retroviral infection itself still remains under investigation.

The focus of this review is to highlight the immunological phenomena that occur in the skin of HIV-1-seropositive patients, which ultimately lead to skin disorders, such as seborrhoeic dermatitis, atopic dermatitis, psoriasis and eosinophilic folliculitis. Furthermore, we compile the latest data on how shifts in the cytokines milieu, impairments of the innate immune compartment, reactions to xenobiotics and autoimmunity are causative agents in HIV-1-driven skin diseases. Additionally, we provide a thorough analysis of the small animal models currently used to study HIV-1-associated skin complications, centering on transgenic rodent models, which unfortunately, have not been able to fully unveil the role of HIV-1 genes in the pathogenesis of their primarily associated dermatological manifestations.

Localization of PSORS1 to a haplotype block harboring HLA-C and distinct from corneodesmosin and HCR

Psoriasis is a complex inflammatory disease of the skin affecting 1-2% of the Caucasian population. Associations with alleles from the HLA class I region (now known as PSORS1), particularly HLA-Cw*0602, were described over 20 years ago. However, extensive linkage disequilibrium (LD) within this region has made it difficult to identify the true susceptibility allele from this region. A variety of genes and regions from a 238-kb interval extending from HLA-B to corneodesmosin (CDSN) have been proposed to harbor PSORS1. In order to identify the minimum block of LD in the MHC class I region associated with psoriasis we performed a comprehensive case/control and family-based association study on 242 Northern European psoriasis families and two separate European control populations. High resolution HLA typing of HLA-A, -B and -C alleles was performed, in addition to the genotyping of 18 polymorphic microsatellites and 36 SNPs from a 772-kb segment of the HLA class I region harboring the previously described interval. This corresponded on average to one SNP every 7 kb in the candidate 238 kb region. With all tests, the association was the strongest with single markers and haplotypes from a block of LD harboring HLA-C and SNP n.9. Logistic regression analyses indicated that association seen with candidate genes from the interval such as CDSN and HCR was entirely dependent on association with HLA-Cw*0602 and SNP n.9-G alleles. The previously reported association with CDSN and HCR was observed to be due to the existence of the associated alleles lying on the most commonly over-transmitted haplotype. Rare over-transmitted haplotypes also harbored HLA-Cw*12 alleles. HLA-Cw*12 family members are closely related to HLA Cw*0602, sharing identical sequences in their alpha-2 domains, peptide-binding pockets A, D and E and all 3' introns. The introduction of a potential binding site for the RUNX/AML family of transcription factors in intron 7, is also specific to these HLA-C alleles. These variants need to be investigated further for their role as PSORS1.

Paradoxical exacerbation of psoriasis in AIDS: proposed explanations including the potential roles of substance P and gram-negative bacteria

Psoriasis, a TH1-induced disorder, is not more common in human immunodeficiency virus (HIV) infection than in the general population. However, it may appear for the first time or pre-existing psoriasis may worsen and be difficult to treat in HIV disease. The paradoxical exacerbation of psoriasis in AIDS has not been fully explained. Various explanations have been proposed including (a) the reduction of Langerhans' cells (LCs) in HIV disease, (b) the direct epidermal proliferative effect of HIV, (c) the altered cytokine profile in HIV disease, (d) HIV-induced macrophage nitric oxide (NO) production, (e) the increased CD8/CD4 T-cell ratio in HIV infection and (f) the increased colonization of skin by Staphylococcus aureus. However, the observations that (a) LCs cells play an important role in the pathogenesis of psoriasis and a variety of topical and systemic psoriasis treatments cause a reversible decrease in LC function, (b) psoriasis may improve in end-stage HIV infection, (c) overproduction of some TH2 cytokines and underproduction of IL-2 in HIV infection, and (d) the presence of NO favors a TH2 response over a TH1 response make the first four explanations difficult to interpret. Since psoriasis is exacerbated in HIV infection possibly due to the increased staphylococcal colonization, and psoriatic keratinocytes could aggravate HIV infection through production of TNF-alpha, it could be reasoned that in HIV-positive psoriatics a strong vicious cycle is present between the degree of immune deficiency and the staphylococcal colonization, explaining the poor prognosis of both AIDS and psoriasis in these patients. With reference to the studies which indicate significant involvement of substance P (SP) in the pathogenesis of psoriasis and on the other hand increased release of this agent by HIV-infected immune cells it is proposed that SP plays an important role in creating the paradox. Since in HIV-positive psoriatics the source of SP is largely immune cells not neurons, capsaicin, which exerts its action selectively on a subpopulation of neurons, could not be of significant therapeutic value. As SP significantly enhances HIV-1 replication in latently infected immune cells, psoriatic lesions, being heavily infiltrated with immune cells and having high concentrations of SP, could serve as high HIV-replication foci, with the resultant rapid progression of the infection towards AIDS. Additionally, given that lipopolysaccharide is supposed to exacerbate psoriasis, increase of gram-negative infections or cutaneous colonization with these organisms in AIDS may partly explain the paradox. Understanding the HIV-induced immunodysregulation that is associated with psoriasis in some HIV-seropositive patients may assist in the delineation of the immunopathogenesis of the disease in HIV-seronegative psoriatics.

A putative RUNX1 binding site variant between SLC9A3R1 and NAT9 is associated with susceptibility to psoriasis

Psoriasis (OMIM 177900) is a chronic inflammatory skin disorder of unknown pathogenesis affecting approximately 2% of the Western population. It occurs more frequently in individuals with human immunodeficiency virus, and 20-30% of individuals with psoriasis have psoriatic arthritis. Psoriasis is associated with HLA class I alleles, and previous linkage analysis by our group identified a second psoriasis locus at 17q24-q25 (PSORS2; ref. 7). Linkage to this locus was confirmed with independent family sets. Additional loci have also been proposed to be associated with psoriasis. Here we describe two peaks of strong association with psoriasis on chromosome 17q25 separated by 6 Mb. Associated single-nucleotide polymorphisms (SNPs) in the proximal peak lie in or near SLC9A3R1 (also called EBP50 and NHERF1) and NAT9, a new member of the N-acetyltransferase family. SLC9A3R1 is a PDZ domain-containing phosphoprotein that associates with members of the ezrin-radixin-moesin family and is implicated in diverse aspects of epithelial membrane biology and immune synapse formation in T cells. The distal peak of association is in RAPTOR (p150 target of rapamycin (TOR)-scaffold protein containing WD-repeats). Expression of SLC9A3R1 is highest in the uppermost stratum Malpighi of psoriatic and normal skin and in inactive versus active T cells. A disease-associated SNP lying between SLC9A3R1 and NAT9 leads to loss of RUNX1 binding. This is the second example of loss of a RUNX1 binding site associated with susceptibility to an autoimmune disease. It also suggests defective regulation of SLC9A3R1 or NAT9 by RUNX1 as a susceptibility factor for psoriasis.

Genetics of psoriasis: the potential impact on new therapies

There is considerable epidemiologic evidence that genes play a key role in the pathogenesis of psoriasis. It is also clear that multiple genes are involved and that the disease is genetically heterogeneous. Important interactions with the environment are also implicated in its development. A number of genetic loci have been identified by genome wide linkage scans and two loci have been replicated: PSORS1 on chromosome 6, within the major histocompatibility complex, and PSORS2 on chromosome 17q. Understanding the genetic basis of psoriasis will represent a major advance in our understanding of the disease and will reveal novel disease-specific biologic pathways. This information will be used to develop more specific diagnostic and prognostic tools and also lead to the development of individualized treatment plans. Benefits of the latter include more effective and safer treatments and potentially major pharmaco-economic gain.

Transient CD30+ nodal transformation of cutaneous T-cell lymphoma associated with cyclosporine treatment

BACKGROUND

Mycosis fungoides (MF) may evolve from pre-existing chronic atopic or psoriasiform dermatitis and the histology can be equivocal. Early patch and plaque lesions of MF may evolve into tumors, disseminate to lymph nodes, bone marrow, and internal organs, and/or undergo transformation to a large cell size.

METHODS

A patient with a history of "atopic dermatitis" followed by "psoriasis" rapidly developed exfoliative erythroderma and axillary lymphadenopathy following treatment with cyclosporine. At presentation, biopsy specimens of skin lesions and lymph nodes and staging were obtained. We present the treatment and follow-up of this patient and review the medical literature for similar cases.

RESULTS

Multiple skin biopsy specimens from lesions revealed changes consistent with low-grade, cutaneous, T-cell lymphoma (MF) without evidence of large cell transformation and psoriasiform epidermal hyperplasia. CD30+ large cell transformation was present in the lymph node. Adenopathy and erythroderma resolved without systemic therapy following discontinuation of cyclosporine and treatment with psoralen/ultraviolet A (PUVA), isotretinoin, interferon-alpha, and antimicrobials.

CONCLUSIONS

This case documents a close relationship between atopy, psoriasis, and the development of cutaneous T-cell lymphoma, and illustrates that an immunosuppressive agent, cyclosporine, can dramatically alter the course of the disease.

RAG2-/-, I kappa B-alpha-/- chimeras display a psoriasiform skin disease

Nuclear factor-kappa B, a ubiquitous transcription factor involved in inflammatory and immune responses, is inappropriately activated in several immuno-related diseases, such as allograft rejection, or bronchial asthma. As nuclear factor-kappa B activity is regulated by inhibitor of kappa B (I kappa B), the gene encoding I kappa B-alpha was disrupted in mice to observe the in vivo effects of hyperactivation of nuclear factor-kappa B. I kappa B-alpha-/- mice have constitutive nuclear factor-kappa B activity, severe skin disease, and neonatal lethality. To determine the role of I kappa B-alpha deficient immunocytes in the pathogenesis of the skin disease in adult mice, we utilized the RAG2-deficient blastocyst complementation system to generate RAG2-/-, I kappa B-alpha-/- chimeras. These animals display a psoriasiform dermatitis characterized by hyperplastic epidermal keratinocytes and dermal infiltration of immunocytes, including lymphocytes. Skin grafts transferred from diseased chimeras to recipient nude mice produce hyperproliferative psoriasiform epidermal keratinocytes in response to stimulation. Furthermore, adoptive transfer of lymph node cells from diseased chimeras to RAG2-/- recipient mice recapitulates the disease. Taken together, these characterizations provide evidence to suggest that constitutive activation of nuclear factor-kappa B, due to deficiency in I kappa B-alpha, can invoke severe psoriasiform dermatitis in adult mice. J Invest Dermatol 115:1124-1133 2000

Identification and quantitation of interferon-gamma producing T cells in psoriatic lesions: localization to both CD4+ and CD8+ subsets

Interferon-gamma (IFN-gamma) produced by lesional T cell clones is critical for the induction into G1 of the cell cycle by psoriatic keratinocyte stem cells; however, direct data demonstrating psoriatic lesional T cell subset IFN-gamma expression, and quantitation at a single cell level to calculate in vivo proportions, are lacking. In this study, using flow cytometry of freshly isolated normal and psoriatic lesional T cells from keratome biopsies, we found elevated CD3+, CD4+, and CD8+ T cells in all compartments of psoriatic skin, compared with normals. Using Brefeldin A to induce short-term intracellular accumulation of IFN-gamma in T cells capable of IFN-gamma production, we found that 90% of psoriatic patients have IFN-gamma-producing T cells at a greater proportion of their CD3+ cells than normals, with a mean of 16%+/-3%, as compared with 4%+/-2% in normal epidermis (p = 0.01). Expressed as density in the tissue, the IFN-gamma+ CD3+ cell number in psoriatic epidermis was 97+/-22 per mm2 surface area, as compared with 4.4+/-1.8 per mm2 of normal epidermis (p = 0.002). Thus, the total number of IFN-gamma+CD3+ T cells in the skin of a patient with 20% involvement is estimated to be 3.9 x 10(8). CD4+ and CD8+ IFN-gamma+ T cells were both elevated in psoriatic epidermis (p = 0.04 and p = 0.008, respectively) relative to normal skin. In the dermis, only 44% of patients demonstrated a higher percentage of IFN-gamma-producing T cells than did normals (p = 0.1), possibly indicating dilution, in some patients, by fresh infiltrating T cells. Interleukin-4 was not found by a combination of flow cytometry, reverse transcriptase-polymerase chain reaction, western blot, and immunoprecipitation. In conclusion, a significant portion of lesional T cells in psoriasis are IFN-gamma producing, without interleukin-4. The increased numbers of both IFN-gamma+CD4+ and IFN-gamma+CD8+ T cells indicate that both CD4+ and CD8+ IFN-gamma+ T cells are present in appropriate anatomic locations to sustain the lesional pathology.

[Psoriasis in HIV positive patients]

Two patients with the acquired immunodeficiency syndrome (AIDS) developed psoriasis, one of them presenting the more severe form and the other one the milder form of the disease, were treated with zidovudine per oral via, 200mg 3 times a day. In the first case the therapeutical response was complete. No lesion was verified in the patient after 9 months under maintenance schedule. In the second case, despite the response being clear, after 6 months of treatment, the patient still presented furfuraceous scalings at limbs ever under the medication schedule.

Reiter's syndrome-like pattern in AIDS-associated psoriasiform dermatitis

BACKGROUND

The prevalence of psoriasiform dermatitis in HIV-infected patients is similar to that in the general population, but its clinical severity and the immunosuppression in these patients pose special problems of therapeutic management. Furthermore, a distinctive clinical pattern has been reported in some cases. In order to assess these features in our clinical setting, we have done a retrospective study on the clinical records of all human immunodeficiency virus (HIV)-positive patients with psoriasiform dermatitis requiring systemic treatment.

METHODS

The clinical records were reviewed of seven HIV-positive patients who were referred between 1988 and 1994 to a University Hospital Dermatology Department from an HIV-clinic because of psoriasiform dermatitis, resistant to topical treatment.

RESULTS

The clinical appearance was rather uniform, with the following common features: facial seborrhea, flexural and acral involvement, with pustulosis of the palms and soles, and frequent arthritis. Lesions appeared in nonterminal stages of acquired immunodeficiency syndrome (AIDS). Three patients developed cutaneous lesions after the diagnosis of HIV infection was made and showed the most severe clinical involvement and arthritis. Etretinate, followed by RePUVA, proved to be the most effective systemic therapy prescribed, with only rare adverse effects. Methotrexate was shown to be effective, but it's use was accompanied by hematologic toxicity. Cyclosporine A treatment was moderately effective and was not associated with progression of AIDS.

CONCLUSIONS

A characteristic Reiter-like clinical picture was observed in AIDS-related psoriasiform dermatitis. Etretinate and RePUVA were effective and safe in controlling the lesions. Physiopathologic mechanisms involved in the development of AIDS-related psoriasis might provide an explanation for the outstanding similarity of the clinical pattern in those patients.

Human immunodeficiency virus and the skin: selected controversies

Acquired immunodeficiency syndrome was first recognized as a new disease in 1981 because of the unusual association of Kaposi's sarcoma and Pneumocystis carinii pneumonia in young men. The skin remains one of the most important clinical markers for acquired immunodeficiency syndrome, now recognized as the end stage of infection with the human immunodeficiency virus (HIV). Indeed, an urticarial viral exanthem appearing during seroconversion may allow early identification of newly infected individuals who might benefit from administration of antiviral therapy during plasma viremia. The "asymptomatic HIV infection" is often accompanied by multiple skin complaints, which commonly include xerosis, pruritus, psoriasis/seborrheic dermatitis, and pruritic papular eruptions, the cause of which remains controversial. Psoriasis and Kaposi's sarcoma lesions share features including angiogenesis, dermal dendrocytes infected with HIV, and epidermal hyperproliferation, and are manifested by mice transgenic for HIV provirus or Tat-ltr. Changes in the immune system including T-cell function, antigen response, and shifting cytokine expression as well as a propensity for autoimmune reactions must underlie the skin immunodysfunction occurring in the setting of HIV infection. One of the most unsettling controversies suggested by in vitro data is that ultraviolet light, an effective therapy for HIV-related skin disorders, may actually activate the virus.

Zidovudine for the treatment of HIV-negative patients with psoriasis: a pilot study

BACKGROUND

Zidovudine, an inhibitor of HIV replication, has been reported to improve psoriasis in HIV-positive patients.

OBJECTIVE

Our purpose was to evaluate the safety, tolerance, and effectiveness of oral zidovudine for treating psoriasis in HIV-negative patients in a small, open-label study.

METHODS

Each subject received 200 mg of zidovudine every 4 hours during waking hours, for a total of 1000 mg/day. Treatment was continued for 8 weeks, at which time the patient's response to therapy was evaluated. If a response was evident, treatment was continued for an additional 8 weeks. Clinical response was correlated with histologic changes in skin lesions at 0 and 4 weeks.

RESULTS

Thirty-three percent of HIV-negative patients with psoriasis showed improvement by up to 80% after 16 weeks of therapy; decreased elevation and scaling of the psoriasis plaques were the most notable changes. No complete remissions occurred.

CONCLUSION

This is the first report of the use of zidovudine to treat HIV-negative patients with psoriasis. Although zidovudine was well tolerated, it may be more effective in HIV-positive patients with psoriasis.

Gene for familial psoriasis susceptibility mapped to the distal end of human chromosome 17q

A gene involved in psoriasis susceptibility was localized to the distal region of human chromosome 17q as a result of a genome-wide linkage analysis with polymorphic microsatellites and eight multiply affected psoriasis kindreds. In the family which showed the strongest evidence for linkage, the recombination fraction between a psoriasis susceptibility locus and D17S784 was 0.04 with a maximum two-point lod score of 5.33. There was also evidence for genetic heterogeneity and although none of the linked families showed any association with HLA-Cw6, two unlinked families showed weak levels of association. This study demonstrates that in some families, psoriasis susceptibility is due to variation at a single major genetic locus other than the human lymphocyte antigen locus.

The role of factor XIIIa-positive dermal dendrocytes in HIV-1-positive psoriatics

Factor XIIIa-positive dermal dendrocytes (FXIIIa+ dd) may have an important role in the pathogenesis of psoriasis, in that their numbers are increased in lesional skin compared with non-lesional skin. Moreover, in AIDS-associated Kaposi's sarcoma the number of these cells is also increased, in comparison with the classical type of Kaposi's sarcoma. In addition, patients suffering from HIV-1 infection may develop severe psoriasis. The aim of this study was to examine the distribution of FXIIIa+ dd in lesional and non-lesional skin from seven psoriatic patients with positive HIV-1 serology, and compare the results with age-, sex-, and site-matched HIV-1-negative psoriatic patients. In both patient groups there was an increase of FXIIIa+ dd in the papillary dermis in lesional skin, compared with non-lesional skin (HIV+ [P = 0.007]; HIV- [P = 0.0006]). Positive cells were also observed within the epidermis in lesional skin in both groups. However, there was no significant difference between HIV-1+ and HIV-1- groups in the number of FXIIIa+ dd in the epidermis and dermis (P > 0.05). These findings suggest that, if FXIIIa+ dd do have a role in psoriasis, deterioration of this condition in HIV-1+ patients is not due to proliferation of dermal dendrocytes.