These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Oncogenic alterations in KIR3DL1 in cutaneous acral CD8+ lymphoproliferative disorder.
    Author: Wobser M, Appenzeller S, Roth S, Siedel C, Goebeler M, Geissinger E, Rosenwald A, Maurus K.
    Journal: Br J Dermatol; 2024 Oct 17; 191(5):816-822. PubMed ID: 38924750.
    Abstract:
    BACKGROUND: Primary cutaneous acral CD8+ T-cell lymphoproliferative disorder (TLPD) is a rare and indolent lymphoma entity. Although TLPD was first identified many years ago, the molecular pathogenesis is still not fully understood. OBJECTIVES: In order to better understand the molecular pathogenesis of cutaneous acral CD8+ TLPD and to identify further discriminatory markers to differentiate this lymphoma subtype from other CD8+ cutaneous lymphomas, we analysed five cases of cutaneous acral CD8+ TLPD for putative molecular alterations. METHODS: Somatic alterations were assessed using whole-exome and targeted sequencing of paraffin-embedded tissue. Results were evaluated using immunohistochemical staining of respective relevant proteins. CD8+ cutaneous T-cell lymphomas (n = 12) served as control for KIR3DL1 staining. RESULTS: Copy number variation analysis revealed a homozygous deletion of the KIR3DL1 gene in two of the analysed cases. This resulted in loss of KIR3DL1 protein expression, which was observed in all cases of cutaneous acral CD8+ TLPD. In contrast, KIR3DL1 expression was more variable in other CD8+ cutaneous T-cell lymphomas with 50% of analysed cases (n = 12) found to be positive. In addition, one further case of acral CD8+ TLPD harboured a loss-of-function mutation in the PIK3R1 gene, presumably activating the phosphoinositide 3-kinase-AKT pathway. CONCLUSIONS: Alterations of the KIR3DL1 gene may be of pathogenetic relevance for acral CD8+ TLPD. Loss of KIR3DL1 protein expression may support the diagnosis of this indolent lymphoma entity; however, this is not a subtype-specific discriminative feature. Cutaneous acral CD8+ T-cell lymphoproliferative disorder (TLPD) is a very rare form of lymphoma, with only around 60 cases reported worldwide. The progression of this lymphoma is usually slow, and most people will present with a solitary plaque or a small papule, without any risk of rapid worsening. For this reason, treatment directly on the skin with topical steroids, excision or radiation are usually sufficient. However, it can be difficult to differentiate this type of lymphoma from other CD8+ cutaneous types upon microscopy. This is important because other CD8+ cutaneous lymphomas can follow an aggressive course and will need to be treated differently, using systemic therapies. Previous findings have shown that abnormal expression of a protein (called CD68) in a dotlike pattern is a specific feature of acral CD8+ TLPD and could help to accurately diagnose this lymphoma. Until now, the underlying molecular differences in cutaneous acral CD8+ TLPD have not been identified. Therefore, this German study was carried out to look at the genetic alterations in the tissue of five patients with this type of lymphoma. To do this, we used a method that examined whole-exome and targeted gene sequencing. We detected alterations in a gene important for T-cell function (called KIR3DL1), in two of five analysed cases. Of note, a loss of KIR3DL1 protein expression has been observed in all analysed cases of acral CD8+ TLPD. Our study findings suggest that genetic defects in KIR3DL1 in acral CD8+ TLPD could be a novel diagnostic marker for this lymphoma subtype and may help to better distinguish it from other, potentially aggressive forms of cutaneous lymphoma.
    [Abstract] [Full Text] [Related] [New Search]