The course of neurofibromatosis type 1 on immunosuppression after lung transplantation: report of 2 cases

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

Phenotype and Outcomes of Pulmonary Hypertension Associated with Neurofibromatosis Type 1

Rationale: Pulmonary hypertension (PH) associated with neurofibromatosis type 1 (NF1) is a rare and largely unknown complication of NF1.Objectives: To describe characteristics and outcomes of PH-NF1.Methods: We reported the clinical, functional, radiologic, histologic, and hemodynamic characteristics, response to pulmonary arterial hypertension (PAH)-approved drugs, and transplant-free survival of patients with PH-NF1 from the French PH registry.Measurements and Main Results: We identified 49 PH-NF1 cases, characterized by a female/male ratio of 3.9 and a median (minimum-maximum) age at diagnosis of 62 (18-82) years. At diagnosis, 92% were in New York Heart Association functional class III or IV. The 6-minute-walk distance was 211 (0-460) m. Pulmonary function tests showed low Dl_CO (30% [12-79%]) and severe hypoxemia (Pa_O2 56 [38-99] mm Hg). Right heart catheterization showed severe precapillary PH with a mean pulmonary artery pressure of 45 (10) mm Hg and a pulmonary vascular resistance of 10.7 (4.2) Wood units. High-resolution computed tomography images revealed cysts (76%), ground-glass opacities (73%), emphysema (49%), and reticulations (39%). Forty patients received PAH-approved drugs with a significant improvement in functional class and hemodynamic parameters. Transplant-free survival at 1, 3, and 5 years was 87%, 54%, and 42%, respectively, and four patients were transplanted. Pathologic assessment showed nonspecific interstitial pneumonia and major pulmonary vascular remodeling.Conclusions: PH-NF1 is characterized by a female predominance, a low Dl_CO, and severe functional and hemodynamic impairment. Despite a potential benefit of PAH treatment, prognosis remains poor, and double-lung transplantation is an option for eligible patients.

NF1 heterozygosity fosters de novo tumorigenesis but impairs malignant transformation

Neurofibromatosis type 1 (NF1) is an autosomal genetic disorder. Patients with NF1 are associated with mono-allelic loss of the tumor suppressor gene NF1 in their germline, which predisposes them to develop a wide array of benign lesions. Intriguingly, recent sequencing efforts revealed that the NF1 gene is frequently mutated in multiple malignant tumors not typically associated with NF1 patients, suggesting that NF1 heterozygosity is refractory to at least some cancer types. In two orthogonal mouse models representing NF1- and non-NF1-related tumors, we discover that an Nf1^+/− microenvironment accelerates the formation of benign tumors but impairs further progression to malignancy. Analysis of benign and malignant tumors commonly associated with NF1 patients, as well as those with high NF1 gene mutation frequency, reveals an antagonistic role for NF1 heterozygosity in tumor initiation and malignant transformation and helps to reconciliate the role of the NF1 gene in both NF1 and non-NF1 patient contexts.

Germline mono-allelic loss of the tumour suppressor NF1 predisposes patients to the development of benign lesions but rarely further progression into cancer development. Here the authors use mouse models to show that an NF1 heterozygous microenvironment accelerates the formation of benign tumours but impairs progression to malignancy.

Pulmonary hypertension associated with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1), also known as von Recklinghausen disease, is a frequent autosomal dominant genetic disorder with a prevalence of 1 in 3000. Pulmonary hypertension (PH) associated with NF1 (PH-NF1) is a rare but severe complication of NF1 and is classified as Group 5 PH, defined as “PH with unclear and/or multifactorial mechanisms”. A literature review in PubMed on the association between NF1 and PH identified 18 articles describing 31 cases. PH-NF1 was characterised by a female predominance, an advanced age at diagnosis, an association with parenchymal lung disease in two out of three cases and poor long-term prognosis. NF1 is generally associated with interstitial lung disease but some cases of severe PH without parenchymal lung disease suggest that there could be a specific pulmonary vascular disease. There is no data available on the efficacy of specific pulmonary arterial hypertension treatment in PH-NF1. Therefore, these patients should be evaluated in expert PH centres and referred for lung transplantation at an early stage. As these patients have an increased risk of malignancy, careful assessment of the post-transplant malignancy risk prior to listing for transplantation is necessary. Clinical trials are needed to evaluate promising treatments targeting the RAS-downstream signalling pathways.

Pulmonary hypertension is a rare but severe complication of neurofibromatosis type 1. There are no data about the efficacy of specific PAH treatment in this disease and lung transplantation should be discussed at an early stage.http://ow.ly/JMU030lezfY

The role of the immune system in neurofibromatosis type 1-associated nervous system tumors

With the recent development of new anticancer therapies targeting the immune system, it is important to understand which immune cell types and cytokines play critical roles in suppressing or promoting tumorigenesis. The role of mast cells in promoting neurofibroma growth in neurofibromatosis type 1 (NF1) patients was hypothesized decades ago. More recent experiments in mouse models have demonstrated the causal role of mast cells in neurofibroma development and of microglia in optic pathway glioma development. We review here what is known about the role of NF1 mutation in immune cell function and the role of immune cells in promoting tumorigenesis in NF1. We also review the therapies targeting immune cell pathways and their promise in NF1 tumors.

Face transplantation: on the verge of becoming clinical routine?

Introduction. Face transplantation (FT) is an innovative achievement of modern reconstructive surgery and is on the verge of becoming a common surgical opportunity. This review article was compiled to provide an update on this surgical field, especially regarding clinical outcomes, benefits, and complications implied. Methods. We performed an extensive research on all English-language Medline articles, case reports, and reviews published online until September 15, 2013. Used search terms were “face transplantation,” “face transplant,” “facial transplantation,” “facial transplant,” “face allograft,” and “facial allograft.” Results. To date 27 FTs have been performed worldwide. 19 of these cases have been published in the Medline database. Long-term follow-up reports of FT cases are rare. Three deaths associated with the procedure have occurred to date. The clinical outcomes of FT are satisfying. Reinnervation of sensation has been faster than motor recovery. Extensive functional improvements have been observed. Due to strict immunosuppression protocols, no case of hyperacute or chronic rejection and no graft-versus-host disease have occurred to date. Conclusions. As studies on long-term outcomes are missing, particularly regarding immunosuppression-related complications, FT will stay experimental for the next years. Nevertheless, for a small group of patients, FT already is a feasible reconstructive option.

Sarcomas other than Kaposi sarcoma occurring in immunodeficiency: interpretations from a systematic literature review

PURPOSE OF REVIEW

In immunodeficiency, an increased sarcoma risk is confirmed for Kaposi's sarcoma. Whether rates of other sarcoma subtypes are elevated in the setting of immunodeficiency is not known. We therefore reviewed published case reports on HIV and AIDS patients and organ transplant recipients with sarcomas. For comparison, we assessed sarcomas in the U.S. general population using Surveillance Epidemiology End Results (SEER) data.

RECENT FINDINGS

A total of 176 non-Kaposi sarcoma were identified, 75 in people with HIV and AIDS and 101 in transplant recipients. Leiomyosarcomas (n = 101) were the most frequently reported sarcomas, followed by angiosarcomas (n = 23) and fibrohistiocytic tumors (n = 17). Leiomyosarcomas were reported with two age peaks, in children and young adults. Epstein-Barr virus (EBV) was detected in the tumor cells in 85 and 88% of leiomyosarcomas in HIV-infected people and transplant recipients, respectively. Angiosarcomas and fibrohistiocytic tumors were most frequently reported in men. Among kidney transplant recipients, 20% of sarcomas arose at the site of an arteriovenous fistula. In comparison, leiomyoscarcomas, angiosarcomas, and fibrohistiocytic tumors comprised 16.9, 3.8, and 18.7% of sarcomas in the U.S. general population.

SUMMARY

Leiomyosarcoma and angiosarcoma may occur disproportionately in immunodeficiency. Leiomyosarcomas appear causatively linked to EBV, whereas angiosarcomas might be correlated with an arteriovenous fistula. Additional studies are necessary to understand the contribution of immunodeficiency to the cause of these sarcomas.

Repair of the lower and middle parts of the face by composite tissue allotransplantation in a patient with massive plexiform neurofibroma: a 1-year follow-up study

BACKGROUND

The risk to benefit ratio of face transplantation with a composite tissue allograft remains debatable, although this procedure is technically feasible. We report here a 1-year follow-up of a patient who underwent face transplantation with a composite tissue allograft.

METHODS

On Jan 21, 2007, a 29-year-old man with neurofibromatosis type 1 underwent resection of a massive plexiform neurofibroma diffusely infiltrating the middle and lower part of his face. The main goal was to restore both the cutaneous appearance and function of the face, including, in particular, control of orbicularis oculi and oris muscle contraction. The issues of immunosuppressive therapy, psychological outcome, and social reintergration were addressed, together with the monitoring of graft rejection by biopsies of the skin and mucosa.

FINDINGS

The initial postoperative course was uncomplicated. Two episodes of clinical rejection occurred on days 28 and 64. The second episode was associated with cytomegalovirus infection. Both episodes resolved favourably, with no further clinical signs of rejection, making the reduction of immunosuppressive treatment possible. A year after surgery, the functional outcome was very good, with successful sensory and motor reinnervation in the transplanted territory. Psychological recovery was excellent, with complete social reintegration.

INTERPRETATION

This case demonstrates the feasibility of surgically removing a large part of the face and replacing it with a composite tissue allograft. This facial repair procedure, which seems to have a satisfactory risk to benefit ratio, could be offered in rare and selected cases.

Low recurrence of preexisting extrahepatic malignancies after liver transplantation

The incidence of de novo malignancies is increased in organ transplant recipients, and patients with hepatic carcinomas are at high risk for tumor recurrence after liver transplantation. Data about recurrent cancer after orthotopic liver transplantation (OLT) in patients with a history of nonhepatic malignancy are very limited. We retrospectively analyzed data from 606 adult OLT recipients and identified 37 patients (6.1%) with a preexisting extrahepatic malignancy. In the same group, 43 patients (7.0%) developed de novo cancer. Preexisting malignancies included 26 solid tumors and 11 hematological malignancies, including 7 patients with Budd-Chiari syndrome due to myeloproliferative disorders (MPDs). Patients had been selected for OLT because of the expected good prognosis of their preexisting malignancy. Except for 3 patients, recipients were tumor-free at OLT. The median interval from tumor diagnosis to OLT was 44 months (range, <1-321). After a median follow-up of 66 months post transplantation (range, 4-131), all but 1 recipient with incidental colon carcinoma were free of recurrence. No patient with MPD showed leukemic transformation, whereas a patient with neurofibromatosis experienced growth of skin fibromas. Our data and an included review of published OLT recipients with preexisting malignancies have enabled us to show that recurrence rates are comparable for nontransplanted patients and renal-transplant recipients. In conclusion, cancer recurrence is low if OLT recipients are carefully selected. Therefore, previous extrahepatic malignancy should not be considered a contraindication for OLT per se, but the oncologic/hematologic prognosis should be considered, particularly with respect to the current 5-year survival rate of OLT.