Kiarash Khosrotehrani

Increased risk for nonmelanoma skin cancers in patients who receive thiopurines for inflammatory bowel disease.

BACKGROUND & AIMS Patients with inflammatory bowel disease (IBD) who have been exposed to thiopurines might have an increased risk of skin cancer. We assessed this risk among patients in France. METHODS We performed a prospective observational cohort study of 19,486 patients with IBD, enrolled from May 2004 to June 2005, who were followed up until December 31, 2007. The incidence of nonmelanoma skin cancer (NMSC) in the general population, used for reference, was determined from the French Network of Cancer Registries. RESULTS Before the age of 50 years, the crude incidence rates of NMSC among patients currently receiving or who previously received thiopurines were 0.66/1000 and 0.38/1000 patient-years, respectively; these values were 2.59/1000 and 1.96/1000 patient-years for the age group of 50 to 65 years and 4.04/1000 and 5.70/1000 patient-years for patients older than 65 years. Among patients who had never received thiopurines, the incidence of NMSC was zero before the age of 50 years, 0.60/1000 for the ages of 50 to 65 years, and 0.84/1000 for those older than 65 years. A multivariate Cox regression model stratified by propensity score quintiles showed that ongoing thiopurine treatment (hazard ratio [HR], 5.9; 95% confidence interval [CI], 2.1-16.4; P = .0006) and past thiopurine exposure (HR, 3.9; 95% CI, 1.3-12.1; P = .02) were risk factors for NMSC. They also identified age per 1-year increase as a risk factor for NMSC (HR, 1.08; 95% CI, 1.05-1.11; P < .0001). CONCLUSIONS Ongoing and past exposure to thiopurines significantly increases the risk of NMSC in patients with IBD, even before the age of 50 years. These patients should be protected against UV radiation and receive lifelong dermatologic screening.

Multi-lineage potential of fetal cells in maternal tissue: a legacy in reverse.

Fetal cells circulate in pregnant women and persist in blood and tissue for decades post-partum. The mother thus becomes chimeric. Factors that may influence such fetal cell microchimerism include histocompatibility, fetal or placental abnormalities, or a reproductive history that includes miscarriage or elective termination. Fetal cell microchimerism is associated with some maternal autoimmune diseases, such as systemic sclerosis. Moreover, a novel population of fetal cells, the pregnancy-associated progenitor cells (PAPCs), appears to differentiate in diseased or injured maternal tissue. The cellular origin of these cells is at present unknown but could be a hematopoietic stem cell, a mesenchymal stem cell, or a novel cell type. Pregnancy therefore results in the acquisition of cells with stem-cell-like properties that may influence maternal health post-partum. Rather than triggering disease, these cells may instead combat it.

Cervical cancer and microchimerism

OBJECTIVE To determine whether microchimerism is involved in the pathogenesis or progression of cervical cancer. METHODS Cervical tissue was obtained from eight women who had at least one live-born son and who underwent radical hysterectomy after a diagnosis of cervical cancer. Control tissue was obtained from four women without cervical cancer who had at least one live-born son and from three women with cervical cancer and no male births. Tissue sections were analyzed with fluorescence in situ hybridization for the presence of fetal cells, defined by an X and Y chromosome. Immunolabeling was used to determine the phenotype of the presumed fetal cells. RESULTS Male cells were found in cervical tissue from all four patients for whom large sections (approximately 1.5 x 2 cm) were analyzed. Only one male cell was found in two of the four patients for whom small biopsy specimens (approximately 0.1 x 0.5 cm) were analyzed. No male cells were found in tissue specimens from controls, whether they were small or large sections. In immunolabeling studies, eight of 18 male cells from one patient were CD45-positive and nine of 37 male cells from two patients were cytokeratin-positive. No cells were positive for both markers. CONCLUSION Cervical cancer might be associated with microchimerism, possibly from fetomaternal cell trafficking. These results further expand the potential relationship between microchimerism and disease in women.

Skin Carcinoma Arising From Donor Cells in a Kidney Transplant Recipient

The incidence of skin cancer is increased in transplant recipients. UV radiation, papillomaviruses, and immunosuppression participate in the pathogenesis of these tumors. In addition, donor cells may leave the grafted organ, reach peripheral tissues and either induce immune phenomena or possibly take part in tissue remodeling. Herein, we investigated the possible involvement of donor cells in the development of skin tumors in kidney allograft recipients. We analyzed a series of 48 malignant and benign cutaneous tumors developing in 14 females who had been grafted with a male kidney. The number of male cells was measured on microdissected material by quantitative PCR for Y chromosome. In the samples with high levels of male cells, fluorescent in situ hybridization (FISH) with X and Y probes and/or immuno-FISH with anticytokeratin antibodies were carried out. Male cells were detected in 5/15 squamous cell carcinomas and Bowen disease (range 4-180 copies), 3/5 basal cell carcinomas (91-645), 6/11 actinic keratosis (7-102), 2/4 keratoacanthoma (22-41), and 2/5 benign cutaneous lesions (14-55). In a basal cell carcinoma specimen with a high number of male cells, FISH showed that most cells within the tumoral buds were XY. In this lesion, immuno-FISH showed the presence of XY cytokeratin-positive cells indicating that the tumor nests contained male keratinocytes. In contrast, in other female transplants, male cells present in the tumors were not epithelial. In conclusion, stem cells originating from a grafted kidney may migrate to the skin, differentiate, or fuse as keratinocytes that could, rarely, undergo cancer transformation.

Maternal neoangiogenesis during pregnancy partly derives from fetal endothelial progenitor cells

Fetal progenitor cells enter the maternal circulation during pregnancy and can persist for decades. We aimed to determine the role of these cells in tissue inflammation during pregnancy. WT female mice were mated to males transgenic for the EGFP (ubiquitous) or the luciferase gene controlled by the VEGF receptor 2 (VEGFR2; V-Luc) promoter. A contact hypersensitivity reaction was triggered during such pregnancies. Fetal cells were tracked by using real-time quantitative amplification of the transgene (real-time PCR), Y chromosome in situ hybridization (FISH), immunofluorescence or in vivo bioluminescence imaging. Real-time PCR disclosed fetal cells in the inflamed areas in all tested mice (17/17) with higher frequency and numbers in the inflamed compared with the control areas (P = 0.01). Double labeling demonstrated CD31+ EGFP+ fetal cells organized as blood vessels. In WT pregnant mice bearing V-Luc fetuses, a specific luciferase activity signal could be detected at the hypersensitivity site only, demonstrating the elective presence of VEGFR2-expressing fetal cells. In conclusion, using various techniques, we found the presence of fetal endothelial cells lining blood vessels in maternal sites of inflammation. These results imply that fetal endothelial progenitor cells are acquired by the mother and participate in maternal angiogenesis during pregnancy.

Significance of erythema nodosum and pyoderma gangrenosum in inflammatory bowel diseases: A cohort study of 2402 patients

Erythema nodosum and pyoderma gangrenosum are the most common cutaneous manifestations in inflammatory bowel diseases (IBD). We conducted the current study to assess the cumulative prevalence of erythema nodosum and pyoderma gangrenosum in patients with IBD and to appraise their association with demographic, clinical, and prognostic factors related to IBD. Between 2000 and 2005, data for all patients with IBD at our gastroenterology department were prospectively and systematically collected using a standardized protocol. Among 2402 patients (1521 diagnosed with Crohn disease [63.3%] and 744 with ulcerative colitis [31.0%]), 140 (5.8%) had atleast 1 skin manifestation. The most frequent dermatologic symptoms were erythema nodosum (4.0%) and pyoderma gangrenosum (0.75%). In multivariate analyses, erythema nodosum was significantly and independently associated with a diagnosis of Crohn disease (p < 0.001), female sex (p < 0.001), eye and joint involvement (p < 0.001), and pyoderma gangrenosum (p < 0.0001). Among patients with Crohn disease, erythema nodosum was associated with isolated colonic involvement (p = 0.0001). Pyoderma gangrenosum was significantly and independently associated with black African origin (p = 0.003), familial history of ulcerative colitis (p = 0.0005), uninterrupted pancolitis as the initial location of IBD (p = 0.03), permanent stoma (p = 0.002), eye involvement (p = 0.001), and erythema nodosum (p < 0.0001). It is noteworthy that the association between pyoderma gangrenosum and permanent stoma persisted after exclusion of patients with peristomal pyoderma gangrenosum (p = 0.07). In conclusion, neither erythema nodosum nor pyoderma gangrenosum was significantly associated with the severity criteria in IBD; however, their occurrence may reflect a peculiar phenotype among affected patients. Abbreviations: 95% CI = 95% confidence interval, EN = erythema nodosum, IBD = inflammatory bowel diseases, OR = odds ratio, PG = pyoderma gangrenosum, PSHI = Post-Surgical Handicap Index.

Breast cancer stroma frequently recruits fetal derived cells during pregnancy

IntroductionBreast carcinomas associated with pregnancy display a high frequency of inflammatory types, multifocal lesions and lymph node metastasis. Because pregnancy results in transfer to mothers of foetal stem cells that can migrate and differentiate into various tissues, we addressed the issue of whether such cells are present in breast carcinoma associated with pregnancy.MethodsWe analyzed women presenting with such tumours who were pregnant with male foetuses using fluorescence in situ hybridization (FISH), targeting X and Y chromosomes. The foetal cell phenotype was then determined by combining FISH and immunohistochemistry with various antibodies. Statistical analysis was performed using t-test or nonparametric Wilcoxons test.ResultsWe found that foetal cells were present in nine out of 10 carcinomas, in contrast with none of four benign mammary lesions (P < 0.05). Counting foetal and maternal cells showed that the mean number of foetal cells per million maternal cells was 36 in breast cancers and 0 in control samples (P < 0.01). By combining FISH and immunolabelling, we found that foetal cells expressed mainly mesenchymal or, to a lesser degree, epithelial or endothelial markers, but never leucocytes.ConclusionThese findings demonstrate the frequent presence of foetal derived cells essentially in tumour stroma. Given the role played by stroma in tumour proliferation, these findings raise the issue of whether foetal cell can be targeted to influence tumour behaviour.

Pregnancy Allows the Transfer and Differentiation of Fetal Lymphoid Progenitors into Functional T and B Cells in Mothers

T lymphocytes of fetal origin found in maternal circulation after gestation have been reported as a possible cause for autoimmune diseases. During gestation, mothers acquire CD34+CD38+ cells of fetal origin that persist decades. In this study, we asked whether fetal T and B cells could develop from these progenitors in the maternal thymus and bone marrow during and after gestation. RAG−/−-deficient female mice (Ly5.2) were mated to congenic wild-type Ly5.1 mice (RAG+/+). Fetal double-positive T cells (CD4+CD8+) with characteristic TCR and IL-7R expression patterns could be recovered in maternal thymus during the resulting pregnancies. We made similar observations in the thymus of immunocompetent mothers. Such phenomenon was observed overall in 12 of 68 tested mice compared with 0 of 51 controls (p = 0.001). T cells could also be found in maternal spleen and produced IFN-γ in the presence of an allogenic or an Ag-specific stimulus. Similarly, CD19+IgM+ fetal B cells as well as plasma Igs could be found in maternal RAG−/− bone marrow and spleen after similar matings. Our results suggest that during gestation mothers acquire fetal lymphoid progenitors that develop into functional T cells. This fetal cell microchimerism may have a direct impact on maternal health.

Subcutaneous neurofibromas are associated with mortality in neurofibromatosis 1: A cohort study of 703 patients

Neurofibromatosis 1 (NF1) is a common genetic disorder with an autosomal dominant mode of inheritance, an increased morbidity and mortality, and a shorter lifespan. Although the disease is fully penetrant by the age of 8, the variability in symptoms and complications is high, even among members of the same family. The aim of this study was to identify easily recognizable clinical features that may be associated with mortality in a cohort of patients affected with NF1. We used prospectively collected data from the Neurofibromatosis Institute Database (NFID) and included in our analysis 703 patients who fulfilled the NIH diagnostic criteria for NF1. Clinical, especially dermatological features were tested as potential factors associated with mortality. Among the patients, 405 (57.6%) were children and 298 (42.4%) were adults. The mean follow‐up was 2.4 years (median = 0.98, range: 0–15.3 years). Forty patients died during follow‐up, mostly due to tumor development such as sarcoma (n = 18). In the adult population, subcutaneous neurofibromas (odds ratio [OR] = 3.6, 95% confidence interval (CI): [1.2–11.3], P = 0.02) and male gender (OR = 5.6, [1.5–20.9], P = 0.004) were independent predictors of mortality after adjustment for age. Among children, the presence of facial plexiform neurofibromas and pruritus were significantly associated with mortality in univariate analysis. Our study describes independent risk factors of mortality in a large cohort of adult and pediatric patients. Close follow‐up should be obtained for patients presenting with subcutaneous neurofibromas.

Fetal Microchimeric Cells Participate in Tumour Angiogenesis in Melanomas Occurring during Pregnancy

Melanoma is a major malignancy in younger individuals that accounts for 8% of all neoplasias associated with gestation. During pregnancy, a small number of fetal cells enter the maternal circulation. These cells persist and then migrate to various maternal tissues where they may engraft and differentiate, particularly if there is organ damage, adopting the phenotype of the host organ. To understand the relationship between melanoma and pregnancy, we analyzed these tumors in both humans and mice. Fetal cells were detected in 63% of human primary melanomas versus 12% in nevi during pregnancy (P = 0.034) and in 57% of B16 melanomas in pregnant mice but never in normal skin (P = 0.000022). More than 50% of these fetal cells expressed the CD34, CD31, or von Willebrand factor endothelial cell markers. In addition, the Lyve-1 lymphatic antigen was expressed by more than 30% of fetal cells in mice. In conclusion, we show that melanomas during pregnancy frequently harbor fetal cells that have an endothelial phenotype. Further studies are needed to assess whether the fetal contribution to lymphangiogenesis may alter the prognosis of the maternal tumor.