Toll-like receptor 4 and CD14 gene polymorphisms in Tunisian kidney transplantation.

BACKGROUND: Acute and chronic rejections remain an important cause of graft loss after renal transplantation. Currently, activation of innate immune responses through Toll-like receptors (TLRs) is suspected to be implied in the loss of the transplant tolerance. OBJECTIVES: We investigated functional single nucleotide polymorphisms (SNPs) of TLR4 and its coreceptor CD14 in kidney transplantation and looked for any potential role in acute rejection (AR) and chronic allograft nephropathy (CAN) and impact on graft survival. PATIENTS AND METHODS: TLR4 (Asp299Gly) and CD14 (C/T -159) SNPs were detected using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 209 kidney transplant recipients (KTRs) including 132 treated with mycophenolate mofetil (MMF+). AR occurred in 59 patients and 24 were identified as having CAN by biopsy and scored according to the Banff criteria. RESULTS: There were no significant associations between TLR4 and CD14 genotypes and alleles and the occurrence of both AR episodes and CAN. Moreover, TLR4 and CD14 SNPs did not seem to influence kidney graft survival. Analysis according to human leukocyte antigen (HLA) compatibility status, positivity of anti-HLA antibodies, and immunosuppression by MMF confirmed the absence of correlation of the investigated SNPs with the graft outcome. In addition, incidence of post-transplantation infections, including cytomegalovirus (CMV) infections, was not influenced by both TLR4 and CD14 SNPs. CONCLUSION: These results suggest that TLR4 (Asp299Gly) and CD14 (C/T -159) functional SNPs do not play a major role in AR, CAN, and kidney graft survival. Therefore, intragraft monitoring of TLR4/CD14 genes expression by messenger RNA (mRNA) would provide clarity on the exact role of these receptors in graft injuries.

Genetic polymorphisms of inflammatory molecules in Tunisian kidney transplantation.

As chemokines and adhesion molecules play major roles in the process by which leukocytes are recruited from the bloodstream into sites of inflammation, genetic variations in the production or activity of molecules may influence susceptibility to acute rejection episodes. This study sought to determine the impact of recipient monocyte chemoattractant protein-1 (MCP-1), chemokine receptor (CCR2, CCR5), and adhesion molecule (ICAM-1, PECAM-1 and L/E selectin) polymorphisms on acute rejection after renal transplantation. We selected 169 healthy blood donors and 173 renal transplant recipients for analysis according to the presence or absence of graft rejection in the first 30 days after transplantation. Using molecular methods DNA was genotyped for 11 polymorphisms of these inflammatory molecules genes. Results were stratified by the incidence of rejection episodes and by human leukocyte antigen (HLA) mismatching. No association was detected between adhesion molecule polymorphisms and the incidence of acute rejection episodes. However, a significant risk of acute renal loss was observed among HLA-identical recipients who possessed the CCR2-64I allele (odds ratio 0.24, 95% confidence interval, 0.05 to 1.06; P=.035). In conclusion, the observed association of CCR2-64I with acute rejection episodes should be added to the spectrum of immunogenetic factors known to be involved in renal allograft rejection.

(AT) repeat in the 3' untranslated region of the CTLA-4 gene and susceptibility to acute allograft rejection in Tunisian renal transplantation.

Allograft rejection is an immune response relying on the proliferation and the differentiation of T cells. CTLA-4 is a co-stimulatory molecule, expressed on activated T lymphocytes, which has been shown to play a crucial role in the down-regulation of T-cell activation. Herein, we have examined the impart of a genetic marker in the CTLA-4 gene on renal transplant outcomes. A cohort of 144 renal recipients and 100 healthy subjects were genotyped by the fragments analysis method using an automated sequencer. Patients were classified into two groups: Group I included 31 HLA-identical haplotype allograft recipients and Group II, 113 showing one or more HLA haplotype mismatches. Forty patients (27.78%) developed at least one acute rejection episode (ARE): 9 in Group I and 31 in Group II. Before transplantation, 20 patients were lymphocytotoxic antibodies (LCT) positive: 4 Group I, 2 of whom developed an ARE, and sixty in Group II, including 8 with an ARE. The occurrence of an ARE was associated with the presence of LCT before transplantation among the entire cohort of patients (P = .032) and among Group II (P = .037). The allelic frequencies of (AT)n polymorphism did not reveal significant differences between patients and controls. The most prevalent alleles were the 88 bp (51% in controls and 44.44% in patients) and the 106 bp (8% and 10.76%, respectively). We noticed an increase of the 120 bp allele frequency among patients who had undergone an ARE compared with those who did not display this complication (8.75% vs 3.85%). Likewise, among LCT-negative Group I, recipients the incidence of the 120 bp allele was higher in ARE than non-ARE patients. Although the differences were not statistically significant, we propose that the 120 bp allele of the CTLA-4 gene (AT)n microsatellite a predisposes to acute rejection episodes in renal transplantation.

Genetic polymorphisms of immunoregulatory proteins in acute renal allograft rejection.

CTLA-4 and CD28 are T lymphocyte receptors involved in the regulation of T-cell activation. Allograft rejection is an alloimune response which is strongly dependent on T-cell proliferation. Thus, we examined the relationship between CTLA-4 and CD28 gene polymorphisms and renal transplant outcomes. We genotyped 141 renal recipients and 229 healthy controls using PCR-SSP methods for the (-318) C/T polymorphism in the promoter region of the CTLA-4 gene and IVS3 (+17) T/C on intron 3 of the CD28 gene, and by PCR-RFLP method for exon 1 (+49) A/G and CT60 G/A within the 3'-untranslated region (UTR) of the CTLA-4 gene. Patients were classified into two groups: Group I included 23 HLA-identical haplotype allograft recipients and group II, 118 recipients with one or more mismatches in HLA haplotypes. Thirty-six patients developed at least one acute rejection episode (ARE). No significant differences were observed between the genotypes or the allele distribution between ARE and non-ARE patients. However, in group I, (+49) A and CT60 (G) allele frequencies were lower in patients with ARE than those without ARE (0.100 and 0.400 vs 0.361 and 0.722 respectively). However, the difference was not significant. Our study suggested that these alleles may confer protection against renal allograft loss.

[Giant cell fibroblastoma associated with Darier-Ferrand dermatofibrosarcoma in an adult]. / Association d'un fibroblastome à cellules géantes et d'un dermatofibrosarcome de Darier-Ferrand chez un adulte.

INTRODUCTION: Giant cell fibroblastoma is a rare mesenchyma tumor of childhood having many similarities with dermatofibrosarcoma protuberans in adults. OBSERVATION: We report the case of a 28-year-old woman presenting a subcutaneous inter-mammary mass associating both tumors. Immunohistochemistry showed an expression of CD 34 only by dermatofibrosarcoma protuberans cells. DISCUSSION: It is important to stress: the rarity of this association, the difficulty to confirm the diagnosis and to establish the links between these two tumors: simple association (as in our case), transformation or recurrence of giant cell fibroblastoma in dermatofibrosarcoma protuberans.

[Secondary head and neck osteosarcoma following treatment of undifferentiated nasopharyngeal neoplasms (UCNT)]. / Ostéosarcome secondaire de la tête et du cou après traitement de carcinome indifférencié du nasopharynx (UCNT).

Secondary tumours after radio and/or chemotherapy are mainly of hematopoietic (acute non lymphoblastic leukemia, non-Hodgkin lymphoma) or soft tissue lineage previously described most frequently after breast cancer and Hodgkin disease treatment with radio and/or chemotherapy. We report two cases of classical osteosarcoma's observed 9 and 3 years after treatment for UCNT with combined radiotherapy and alkylant-based adjuvant chemotherapy in one case and exclusive loco-regional irradiation in the second case.

[Extended melanocytic tumor of the cervical spine. Apropos of a case of melanotic schwannoma]. / Tumeur mélanique étendue du rachis cervical. A propos d'un cas de schwannome mélanotique.

A case of melanotic tumour was described localized close to the right cervical spine, destroying C6 and C7 vertebral bodies and pedicles, on a 27 years old woman. Histological and immunohistochemical findings, correlated with clinical and X-rays data, led up to the diagnosis of a melanotic schwannoma. Six years after the beginning of the illness, the outcome was preceded by a local vertebral involvement without metastasis and paradoxically with a good general state. The tumoral localization and the finding of nervous structures allowed to evoke a development from a cervical nerve root. On histological basis, we propose to classify this tumour along the new concept described by the Mayo Clinic pathologists team, under the name of psammomatous melanotic schwannoma. Some authors evoke a congenital outset in a context of endocrine disorders.

Digestive tract involvement with exudative enteropathy in Langerhans cell histiocytosis.

Protein-losing enteropathy was observed in two children with Langerhans' cell histiocytosis (LCH). One patient was an infant with congenital cutaneous lesions; the second child had sigmoid and lymph node infiltration. Electron microscopy and immunohistochemistry confirmed, in both, infiltration of duodenum, skin, and liver by LCH. Gastrointestinal involvement by LCH seldom produces prominent clinical manifestations but indicates widespread multisystem disease. Immunohistochemical and/or ultrastructural features allow definitive diagnosis from mucosal biopsy specimens. Review of the literature of gastrointestinal infiltration by LCH emphasizes its poor prognosis, especially when associated with organ dysfunction.

[Characterization of nucleolar organizers in carcinomatous mammmary lesions]. / Caractérisation des organisateurs nucléolaires dans les lésions carcinomateuses mammaires.

An argyrophil stain for nucleolar organizer regions (NORs) has been applied to paraffin sections of 24 malignant and 3 benign breast tumors. It was found that the total number of Ag-NORs in malignant breast lesions (3.66) significantly exceeded those in benign lesions (1.65). Relationship between this index and some clinical parameters was studied. A positive correlation between NORs and histological grading and prognostic was found.