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J Guitart

Publications and source records attributed to J Guitart.

At least 19 recordsLinked to original sources
PubMed2002

Expression of eotaxin, an eosinophil-selective chemokine, parallels eosinophil accumulation in the vesiculobullous stage of incontinentia pigmenti.

Incontinentia pigmenti (IP) is an X-linked dominant genodermatosis primarily affecting female children. The initial vesiculobullous stage of IP is characterized clinically by inflammatory papules, blisters, and pustules, and histopathologically by acanthosis, keratinocyte necrosis, epidermal spongiosis and massive epidermal eosinophil infiltration. The cause of this multisystem disease is attributed to the mutations of an X-linked regulatory gene, termed nuclear factor-kappaB essential modulator (NEMO). The exact mechanism of epidermal eosinophil accumulation has not yet been determined. We explored the possible role of an eosinophil-selective, nuclear factor-kappaB-activated chemokine, eotaxin, in the accumulation of eosinophils in the initial stage of the disease. Monoclonal antibody (6H9) specific for human eotaxin strongly labelled the suprabasal epidermis of IP skin, paralleling the upper epidermal accumulation of eosinophils, but did not label the epidermis of normal skin or lesional skin from patients with other inflammatory skin diseases not characterized by prominent eosinophil accumulation, namely dermatitis herpetiformis and selected cases of atopic dermatitis lacking significant numbers of eosinophils. In addition, endothelial cells in lesional skin of IP also exhibited strong expression of eotaxin, which correlated with perivascular and intravascular eosinophil infiltration. We also examined the in vitro effects on epidermally derived eotaxin of several cytokines that were nuclear factor-kappaB-activated and/or known to induce eotaxin expression. In normal human keratinocytes, proinflammatory cytokines either independently (IL-1alpha) or synergistically (tumour necrosis factor-alpha (TNF-alpha)/ interferon-gamma (IFN-gamma) and TNF-alpha/IL-4) up-regulated eotaxin expression. These studies suggest that release of cytokines during the initial inflammatory stage of IP induces epidermal expression of eotaxin, which may play a role in the epidermal accumulation of eosinophils.

Cells, Cultured↗
PubMed2001

Histologic criteria for the diagnosis of mycosis fungoides: proposal for a grading system to standardize pathology reporting.

BACKGROUND: The histological diagnosis of early lesions of mycosis fungoides (MF) is often difficult for dermatopathologists and prior studies have shown a low agreement rate among pathologists. An important reason for such difficulty may be the lack of specific histological criteria. METHODS: We tested a new method to interpret and report biopsies suspicious for MF. The method is based on a grading system reflecting the pathologist's degree of diagnostic certainty. A panel of four pathologists independently assessed a set of 50 biopsies suspicious for MF first without (Phase I) and subsequently with specific histological criteria (Phase II). A third Phase was carried out after a training session, using a new set of cases with corresponding immunophenotyping and gene rearrangement analysis. Weighted and unweighted kappa statistics were used to assess inter- and intra-pathologist variation. RESULTS: The consensus rate among pathologists improved from 48% in Phase I to 76% in Phase III. Overall precision weighted kappas increased from 0.630 in Phase I to 0.854 in Phase III, indicating excellent inter-pathologist agreement by Phase III. There was a significant association between the presence of an abnormal phenotype and/or T-cell clonality and a higher diagnostic score. CONCLUSIONS: The use of uniform criteria and training sessions can substantially improve the consensus rate among pathologists in the diagnosis of MF.

Biopsy↗
PubMed2001

Absence of Borrelia burgdorferi DNA in cutaneous B-cell lymphomas from the United States.

BACKGROUND: An association between Borrelia burgdorferi and cutaneous B-cell lymphoma (CBCL) has been made in several European countries. The evidence in favor of such an association has recently been based on more definitive tests for the pathogenetic role of B. burgdorferi in CBCL, including positive cultures or polymerase chain reaction (PCR) amplification of borrelial DNA from lesional skin. However, there is only one report of B. burgdorferi in four North American cases of B-cell lymphoma. METHODS: We retrieved 38 cases of primary and secondary CBCL from different geographic regions of the United States. Two separate techniques were used to detect borrelial DNA by PCR, a nested PCR method to amplify a B. burgdorferi-specific gene as well as a borrelial chromosomal Ly-1 clone amplification method. Southern blot hybridization was used for confirmation of the PCR results. RESULTS: No B. burgdorferi-specific DNA was detected in any of the 38 CBCL cases, whereas detectable PCR products were obtained with our positive controls. CONCLUSIONS: Our findings, in light of previous studies, suggest that B. burgdorferi plays a minimal role in the development or pathogenesis of CBCL in the United States. The findings also suggest that the geographic variations in the clinical manifestations of B. burgdorferi are indeed real and may be secondary to the genetic and phenotypic differences between B. burgdorferi strains present in Europe and North America.

Borrelia burgdorferi↗
PubMed2000

Induction of keratinocyte IL-8 expression and secretion by IgG autoantibodies as a novel mechanism of epidermal neutrophil recruitment in a pemphigus variant.

A subset of pemphigus herpetiformis, a rare pemphigus variant, is characterized histopathologically by subcorneal acantholysis and neutrophilic infiltration. The mechanism of neutrophil infiltration is unknown, but chemokines such as IL-8 may play a role. We investigated the possible role of IL-8 in two such cases. Direct and indirect immunofluorescence studies demonstrated in vivo-bound and circulating IgG epithelial cell surface-binding autoantibodies, both predominated by IgG4 subclass. ELISA and immunoblotting studies revealed that the patients' IgG autoantibodies recognized recombinant desmoglein 1 but not desmoglein 3. Preadsorption of the patients' sera with recombinant desmoglein 1 completely removed the epidermal cell surface immunostaining. Significantly, immunohistochemistry demonstrated intense expression of IL-8, co-localized with in vivo-bound IgG, in the upper epidermis, where the acantholysis took place. Affinity-purified sera IgG from these two patients, a normal individual, and a pemphigus vulgaris patient containing desmoglein 1 autoantibodies, were incubated with normal human keratinocytes in vitro. Cells treated with these patients' IgG secreted a seven-to-nine-fold increase of IL-8 (30-37 pg/ml) compared with the controls (2-4 pg/ml) and expressed a higher intensity of cytoplasmic IL-8 staining. These data demonstrate a novel functional role for IL-8 in the pathogenesis of the neutrophil-dominant subset of pemphigus herpetiformis. The autoantibody-induced epidermal cell IL-8 expression may represent a novel mechanism of epidermal neutrophil recruitment.

Adult↗
PubMed2000

Primary cutaneous B-cell lymphoma: review and current concepts.

PURPOSE: Primary cutaneous B-cell lymphoma (PCBCL) has only recently been recognized as a distinct clinical entity. With the advent of improved immunophenotyping and immunogenotyping, increasing numbers of PCBCL cases are being diagnosed. However, there is much confusion regarding the classification, treatment, and prognosis of these patients. The purpose of this article is to review and analyze the available data to provide the clinician with a concise summary of the diagnosis, prognosis, and treatment of PCBCL. DESIGN: We conducted a thorough review of the medical literature on PCBCL, with a focus on classification, prognosis, and treatment trials. RESULTS AND CONCLUSION: PCBCL is defined as a B-cell lymphoma originating in the skin. There is no evidence of extracutaneous disease at presentation and for 6 months after diagnosis, as assessed by adequate staging procedures. Currently, the European Organization for Research and Treatment of Cancer classification is the most concise disease classification scheme, dividing the subtypes of PCBCL by clinical behavior and histopathologic findings. Based on this classification, the most common subtype of PCBCL is follicular center cell lymphoma. PCBCL is generally an indolent form of lymphoma with a good prognosis. Although local cutaneous recurrences are observed in 25% to 68% of patients, dissemination to internal organs is rare. Five-year survival rates typically range from 89% to 96%. A specific subtype, large B-cell lymphoma of the leg, is noted to have a poorer prognosis, with a 5-year survival rate of 58%. Overly aggressive treatment of PCBCL has not been shown to improve survival or prevent relapse. The treatment of choice usually varies depending on the type of PCBCL, the body surface area, and the location of the involvement, as well as the age and general health condition of the patient. The majority of studies indicate that PCBCL is highly responsive to radiation therapy. Polychemotherapy should be reserved for involvement of noncontiguous anatomic sites or those with extracutaneous spread.

Humans↗
PubMed2000

Primary cutaneous T-cell lymphoma: review and current concepts.

PURPOSE: Primary cutaneous T-cell lymphomas (CTCLs) encompass a wide variety of lymphomas that are characterized by the localization of the malignant lymphocytes to the skin at presentation. Advances in molecular biologic techniques, including immunophenotyping and gene rearrangement studies to determine clonality, have led to more frequent diagnosis of CTCL as well as more consistent subclassification of these entities. However, there continues to be confusion in the classification, prognosis, and management of patients with CTCL. The purpose of this review is to present a summary of the diagnosis, prognosis, and treatment of CTCL, with specific emphasis on mycosis fungoides (MF) and Sézary syndrome (SS). We also present a detailed discussion of the entities that make up the differential diagnosis of CTCL. DESIGN: We reviewed the medical literature on CTCL and other diseases that make up the differential diagnosis of CTCL. RESULTS AND CONCLUSION: MF and SS are the most common forms of CTCL. The etiology of this disease is still unknown. Patients may go for months to years with skin abnormalities before being diagnosed. MF/SS is an indolent disease and patients with T1 disease have a normal life expectancy. Patients who undergo transformation to large-cell lymphoma (8% to 23% of patients) have a poor prognosis, with mean survival ranging from 2 to 19 months. Treatment for MF/SS continues to be palliative. There are many new therapies that are currently being investigated in clinical trials, and the DAB(389)IL-2 fusion protein was recently approved for the treatment of refractory MF/SS.

Diagnosis, Differential↗
PubMed1999

A new polymerase chain reaction-based method for the detection of T-cell clonality in patients with possible cutaneous T-cell lymphoma.

OBJECTIVE: To evaluate a new, rapid, and sensitive method for the detection of T-cell clonality in patients with lesions suggestive of cutaneous T-cell lymphoma (CTCL). DESIGNS: Skin specimens were obtained from 48 patients with possible CTCL. Polymerase chain reaction amplification of the T-cell receptor gamma (TCRG) gene was performed using consensus primers to the V and J regions. Clonal populations having identical N-region sequences are detected by single-strand conformation polymorphism analysis using a semiautomated electrophoresis system with a silver-staining method for gel visualization. The results of clinicopathological assessment were compared with those of immunohistochemistry and polymerase chain reaction analysis. SETTING: Cutaneous lymphoma clinic at a university medical center. PATIENTS: Forty-eight patients with skin lesions suggestive of CTCL. RESULTS: Based on the clinicopathological assessment, 26 patients were diagnosed as having CTCL. Of them, clonality was detected in 19 patients (73%) and an abnormal phenotype in 17 (68%) of 25 patients. Combining both tests, abnormal results were noted in 24 (92%) of 26 patients with CTCL. Clonality was also identified in 2 (12%) of 17 patients with presumably benign lesions on clinicopathological assessment. CONCLUSIONS: Polymerase chain reaction and single-strand conformation polymorphism analysis of the TCRG gene is a rapid and sensitive method that can contribute to the diagnosis of CTCL. The new method is especially useful when used in conjunction with immunophenotyping.

Adult↗
PubMed1999

Cutaneous CD8 T cell infiltrates in advanced HIV infection.

BACKGROUND: Aggressive non-Hodgkin's lymphomas are common among patients infected with HIV. Although such lymphomas are mostly of the B-cell type, various cases of cutaneous T-cell lymphoma (CTCL) have also been reported. Recent reports suggest that some HIV-related lymphoproliferative conditions may not be clonal processes, but polyclonal lymphoid proliferations. OBJECTIVE: We reviewed our experience with HIV patients seen at the dermatology clinics for possible CTCL. METHODS: A retrospective study was performed to evaluate clinical, laboratory, and histologic findings of HIV-infected patients with atypical T-cell cutaneous infiltrates. RESULTS: We observed 9 patients with advanced HIV infection and a cutaneous eruption characterized by a dense infiltrate of lymphocytes resembling mycosis fungoides histopathologically, but composed of CD8(+) cells. Although clonality was not identified in any of the 6 cases tested, 3 patients had similar CD8(+) infiltrates involving lymph nodes or bone marrow. Of the 9 patients, 8 died of AIDS wasting syndrome or infections in less than 1 year. CONCLUSION: Cutaneous and systemic infiltrates with polyclonal CD8 T lymphocytes can be seen in patients with advanced HIV infection and profound CD4 lymphopenia. The clinical presentation may resemble CTCL and is associated with a poor outcome.

Adult↗
PubMed1999

Pleomorphic T-cell infiltrate associated with molluscum contagiosum.

The authors observed a pleomorphic lymphocytic infiltrate composed of CD8 cytotoxic/suppressor T-cells in two pediatric cases associated with molluscum contagiosum. T-cell clonality was not detected. In both cases, the lesions resolved after the biopsy was performed. The patients were otherwise healthy, and no evidence of lymphoproliferative process was detected on follow-up. The authors believe the pleomorphic lymphoid infiltrate is inflammatory and reactive in nature. The close apposition of lymphocytes to molluscum bodies and cytoid bodies with high expression of CD30 and the proliferating marker Ki67 is suggestive of a cytotoxic cell-mediate blastic reaction against poxvirus antigens.

Antigens, CD20↗
PubMed1999

O6-alkylguanine-DNA alkyltransferase in cutaneous T-cell lymphoma: implications for treatment with alkylating agents.

Mycosis fungoides is a low-grade cutaneous T-cell lymphoma. Early treatment often involves the use of topical chemotherapy such as mechlorethamine or carmustine although single-agent oral chemotherapy with alkylators is common for advanced disease. Recently, in a Phase I study of the new alkylating agent temozolomide, two mycosis fungoides patients experienced a complete response. The mechanism of resistance to alkylating drugs such as temozolomide is thought to be due to the presence in tumor cells of the DNA repair protein, O6-alkylguanine-DNA alkyltransferase (AGT). The protein mediates a reaction with the O6-position of guanine in DNA, removing the lesion and leaving guanine intact. We, therefore, examined the levels of AGT in CD4+ T lymphocytes obtained by negative antibody selection from the blood of noncancerous individuals and mycosis fungoides patients, and in paraffin-embedded sections from mycosis fungoides patch, plaque, or tumor lesions and cells from involved lymph nodes. AGT protein levels were measured by quantitative immunofluorescence microscopy using a monoclonal antibody against human AGT. Using this approach, the mean level of our positive control (AGT-expressing cells) was 84,807 molecules/nucleus; values below 5,000 molecules/nucleus are considered very low. The mean AGT level in CD4+ T lymphocytes from noncancerous and cancerous individuals was 18,618 (n = 12) and 8,593 (n = 5), respectively. The mean fraction of outliers in circulating CD4+ T lymphocytes from mycosis fungoides patients was statistically significantly lower than T cells in lymph nodes. AGT molecules/nucleus from lymph node biopsies from 8 of 10 patients showed low (< 10,000 molecules/nucleus) or undetectable levels (n = 5) of AGT. The mean AGT level from samples of mycosis fungoides patch/plaque and tumor was also low at 221 (n = 4) and 2,363 (n = 6), respectively. Surprisingly, Hut78, a mycosis fungoides T-cell lymphoma cell line, was positive for AGT activity (median: 77,700 molecules/nucleus), and Hut102--another mycosis fungoides cell line--was low (median: 5,990 molecules/nucleus). Because AGT is a primary means of cell resistance to alkylating agents, the low level of AGT in neoplastic T lymphocytes from patients with mycosis fungoides suggests that treatment with alkylating agents producing O6-alkylguanine adducts, such as carmustine or temozolomide, may produce improved clinical outcomes.

Adult↗