Intravascular lymphomatosis of the skin as a manifestation of recurrent B-cell lymphoma.

Intravascular lymphomatosis (IVL) is a rare type of lymphoma with a poor prognosis. Its distinctive clinical and histopathologic features are generated by the proliferation of neoplastic mononuclear cells within blood vessels. We describe a patient with IVL of the skin as a manifestation of a recurrent diffuse large B-cell lymphoma of ureteral origin. Lymphoma cells were located both within the vessels and the parenchyma in an early cutaneous lesion. After recurrence in the skin, lymphoma cells gradually located only in the vascular lumina. This transition suggests that cells localized within the vessels were selected as a consequence of chemotherapy. Immunohistochemical examination revealed that the expression of surface adhesion molecules of lymphoma cells did not significantly change. The results of polymerase chain reaction revealed that the ureteral and cutaneous tumors were identical in clonality. Our findings suggest that conventional diffuse large B-cell lymphoma can change into IVL.

Initial recruitment of interferon-gamma-producing CD8+ effector cells, followed by infiltration of CD4+ cells in 2,4,6-trinitro-1-chlorobenzene (TNCB)-induced murine contact hypersensitivity reactions.

Contact hypersensitivity (CHS) is an antigen-specific, T-cell-mediated skin reaction in sensitized individuals. Recent studies have demonstrated that the murine CHS reaction to 2,4-dinitrofluorobenzene (DNCB) is mediated by CD8+ T cells and down-regulated by CD4+ T cells. We studied cellular events and functions of infiltrating cells in CHS reactions to 2,4,6-trinitro-1-chlorobenzene (TNCB) in the skin and draining lymph nodes (LN) of BALB/c mice and compared them with the CHS reaction to a house dust mite antigen, Dermatophagoides farinae (Df). Mice were sensitized with TNCB or Df antigens, and CHS reactions elicited with the corresponding antigens were examined immunohistologically. Cytokines produced by individual cells isolated from the CHS reactions were analyzed by flow cytometry, and the expression of cytokine mRNA was assayed by reverse transcription-polymerase chain reaction (RT-PCR). Results demonstrated that the intensity of TNCB-elicited CHS skin reactions reached its peak at 24 hr after elicitation and decreased gradually. Flow cytometric analysis of isolated cells from the TNCB-elicited CHS reactions demonstrated that the infiltrating cells were composed of approximately 25% CD4+ and CD8+ cells at 12, 24, and 36 hr after challenge, although infiltrating cells became dense at 36 hr by histological observation. The percentage of IFN-gamma-producing CD8+ cells (Tc1) in the cell fractions reached its peak at 12 hr and decreased gradually. The peak infiltration of IFN-gamma-producing CD4+ cells (Th 1) was observed at 24 hr. IL-4-producing cells, however, were always below 5% in the cell fractions. The RT-PCR method demonstrated that IFN-gamma mRNA was detected in the TNCB-elicited skin reactions at 12, 18 and 24 hr after elicitation, became weak at 48 hr, and disappeared at 72 hr. No IL-4 mRNA was detected from 12 to 72 hr. In the draining LN cells, however, the percentages of both IFN-gamma-producing CD8+ (Tc1) and CD4+ cells (Th1) decreased 12 to 36 hr after TNCB elicitation. CHS reactions of Df antigens were predominantly composed of infiltrations of CD4+ cells in to the skin, associated with the expression of IL-4 mRNA from 12 to 48 hr after elicitaion. The expression of IFN-gamma mRNA was detected at 48 hr or later. Our findings indicate that the CHS skin reaction to TNCB is induced by early recruitment of IFN-gamma-producing CD8+ effector cells (Tcl), followed by infiltration of IFN-gamma-producing CD4+ cells (Th1), whereas IL-4-producing T cells (Th2) induce the early CHS response to Df antigens.

Comparison of the severity of atopic dermatitis lesions and the density of Staphylococcus aureus on the lesions after antistaphylococcal treatment.

We examined the relationship between atopic dermatitis (AD) and Staphylococcus aureus by comparing changes in AD lesions and the bacterial density on the lesions after antimicrobial treatment with cefdinir. We found that there was a greater density of S. aureus on red erythemas and exudative lesions than in light/dark red erythemas and non-exudative lesions of AD. Forty-one of 59 cases (69%) showed a decrease in colony count following antimicrobial treatment. In 28 of 39 cases (72%) there was a decrease of erythema, and in 18 of 22 cases (82%) there was a decrease in the amount of exudate both associated with a decrease in colony density following antimicrobial treatment. Because acute phases of atopic dermatitis, such as red erythemas and exudative lesions, were closely related to the colonization of S. aureus, dense colonization with S. aureus may be an important factor in the exacerbation of AD. We believe that staphylococcal products such as α-toxin, various enzymes, coagulase, and superantigenic exotoxins affect some aspect of the inflammatory process, resulting in exacerbation of AD. J Infect Chemother 1996;2:70-74.