Sirolimus treatment for recurrent lymphangioleiomyomatosis after lung transplantation. Ann Thorac Surg. 2009;87:e6-e7. [PMID: 19101258 DOI: 10.1016/j.athoracsur.2008.07.107]

Lung transplantation for lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease, associated with respiratory symptoms of dyspnea and spontaneous pneumothorax, along with various extra-thoracic manifestations. Often a progressive disease, albeit slowly, patients can develop chronic and severe respiratory failure and require supplemental oxygen. Lung transplantation (LTX) can offer improved duration and quality of life for patients with end-stage lung disease due to LAM. There are several unique considerations for LTX in LAM patients, and disease-specific complications of LAM prior to LTX can affect management decisions. Furthermore, there are several possible post-transplant issues specific to LAM. In this review, we discuss evaluation and management, disease-specific complications (both pre- and post-transplant), and outcomes for LAM patients undergoing lung transplantation.

Recurrent lymphangioleiomyomatosis in a lung allograft with COVID-19: autopsy case report and literature review

Lymphangioleiomyomatosis (LAM) is a rare neoplastic disease of the lung with a characteristic feature of diffuse cystic changes in bilateral lungs. Lung transplantation is considered to be one of the effective treatments in end stage disease. Patients with LAM who underwent lung transplant tend to have more favorable outcome compared to other end stage lung diseases. We report a case of a female patient who was diagnosed with LAM and received bilateral lung transplantation at 45 years of age. Subsequent allograft biopsies were significant for mild acute cellular rejection (Grade A2), for which the immunosuppressive regimen was adjusted accordingly. At 7 years post-transplant, she presented with shortness of breath, cough, and fatigue, and diagnosed with a viral infection. Her chest imaging was unremarkable. However, a transbronchial biopsy was performed to rule out rejection and revealed foci of spindle cells proliferation, with positive HMB-45 and smooth muscle actin immunohistochemical studies, confirming the diagnosis of recurrent LAM. After she was discharged, she was re-admitted 1 week later with severe COVID-19. Her clinical course was complicated by acute respiratory distress syndrome, respiratory failure, and gastrointestinal hemorrhage. The patient passed away on day 36 of hospital stay. Autopsy was requested and confirmed the pathology of recurrent LAM and diffuse alveolar damage from COVID-19.

Estimation of Blood Sirolimus Concentration Based on Tacrolimus Concentration/Dose Normalized by Body Weight Ratio in Lung Transplant Patients

BACKGROUND

Sirolimus and tacrolimus require accurate drug dosing based on their target blood levels to produce better clinical outcomes, specifically, the avoidance of drug-induced adverse effects and the maintenance of efficacy. However, because the ideal dose of sirolimus and the schedule for measuring its blood levels are unclear in lung transplant patients, an index is required for estimating sirolimus blood concentrations. The aim of this work is to study the correlation between the trough concentration/dose normalized by body weight (C0/D) ratios of sirolimus and tacrolimus in lung transplant patients.

METHODS

Thirteen lymphangiomyomatosis patients who underwent lung transplantation and were treated with sirolimus and tacrolimus from February 2015 to July 2018 were divided into 2 groups, one receiving twice-daily (TD, n = 6) and the other once-daily (OD, n = 7) tacrolimus formulations. The correlation between the C0/D ratio of sirolimus and patient background was evaluated using Spearman's rank correlation coefficient. Correlations between sirolimus and tacrolimus C0/D ratios or doses were analyzed by single regression analysis.

RESULTS

Significant correlations were found between the C0/D ratios of sirolimus and tacrolimus. The regression equations from the initial data of TD and OD groups at steady state were y = 1.880x + 32.636 (adjusted R = 0.743, P = 0.017) and y = 1.684x + 38.816 (adjusted R = 0.919, P < 0.001), respectively. In addition, the regression equations from all data of TD and OD groups were y = 1.883x + 4.170 (adjusted R = 0.546, P < 0.001) and y = 1.950x + 43.188 (adjusted R = 0.898, P < 0.001), respectively. A significant correlation between the dosage of sirolimus and tacrolimus was observed only in the OD group, with relatively low accuracy.

CONCLUSIONS

Blood sirolimus concentrations can be estimated using the C0/D ratio of tacrolimus, suggesting that the C0/D ratio of tacrolimus is an index of required sirolimus dosage and the frequency of blood sirolimus concentration measurements.

Low-dose sirolimus in retroperitoneal lymphangioleiomyomas

Lymphangioleiomyomatosis (LAM) is a rare disease associated with cystic lung destruction and abdominal tumors, including lymphangioleiomyomas, which frequently occur in the retroperitoneal region. Sirolimus therapy is currently recommended for LAM patients with abnormal or declining lung function with an adjusted dose to maintain a serum trough level of 5–15 ng/mL. We describe a significant reduction of retroperitoneal lymphangioleiomyomas after treatment with low-dose sirolimus therapy (serum trough level <5 ng/mL) in a patient with sporadic LAM.

Insulin growth factor binding protein 2 mediates the progression of lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a progressive pulmonary disease that almost exclusively affects women. LAM cells migrate to the lungs, where they cause cystic destruction of lung parenchyma. Mutations in TSC1 or TSC2 lead to the activation of the mammalian target of rapamycin complex-1, a kinase that regulates growth factor-dependent protein translation, cell growth, and metabolism. Insulin-like growth factor binding protein 2 (IGFBP2) binds insulin, IGF1 and IGF2 in circulation, thereby modulating cell survival, migration, and invasion in neoplasms. In this study, we identified that IGFBP2 primarily localized in the nucleus of TSC2-null LAM patient-derived cells in vitro and in vivo. We also showed that nuclear accumulation of IGFBP2 is closely associated with estrogen receptor alpha (ERa) expression. Furthermore, estrogen treatment induced IGFBP2 nuclear translocation in TSC2-null LAM patient-derived cells. Importantly, depletion of IGFBP2 by siRNA reduced cell proliferation, enhanced apoptosis, and decreased migration and invasion of TSC2-null LAM patient-derived cells. More interestingly, depletion of IGFBP2 markedly decreased the phosphorylation of MAPK in LAM patient-derived TSC2-null cells. Collectively, these results suggest that IGFBP2 plays an important role in promoting tumorigenesis, through estrogen and ERalpha signaling pathway. Thus, targeting IGFBP2 may serve as a potential therapeutic strategy for women with LAM and other female gender specific neoplasms.

Experience of Lung Transplantation in Patients with Lymphangioleiomyomatosis at a Brazilian Reference Centre

INTRODUCTION

Lung transplantation (LT) is the standard of care for patients with advanced lung diseases, including lymphangioleiomyomatosis (LAM). LAM accounts for only 1% of all LTs performed in the international registry. As a result, the global experience, including the use of mechanistic target of rapamycin (mTOR) inhibitors before and after LT in LAM, is still limited.

METHODS

We conducted a retrospective review of all LAM patients who underwent LT at our centre between 2003 and 2016. Pre- and post-transplant data were assessed.

RESULTS

Eleven women with LAM underwent LT, representing 3.3% of all procedures. Ten (91%) patients underwent double-LT. The mean age at diagnosis was 39 ± 6 years and the mean FEV₁ before LT was 28 ± 14%. Only one patient underwent pleurodesis for recurrent pneumothorax. Pulmonary hypertension was confirmed in 3 (27%) patients. Four (36%) patients received sirolimus preoperatively; three of them received it until the day of LT, and there was no occurrence of bronchial anastomotic dehiscence after the procedure. Four patients (36%) received mTOR inhibitors post-transplant. The median follow-up from LT was 44 months. There were 3 deaths (27%) during the study and survival probabilities at 1, 3, and 5 years after LT were, 90, 90, and 77%, respectively.

CONCLUSIONS

This data reinforces the role of LT for LAM patients with end-stage disease. The use of sirolimus seems to be safe before LT and the occurrence of complications after LT, including those LAM-related, should be continuously monitored.

Therapeutic Effect of Sirolimus for Lymphangioleiomyomatosis Remaining in the Abdominopelvic Region After Lung Transplantation: A Case Report

PURPOSE

Sirolimus (SRL) is used to treat pulmonary lymphangioleiomyomatosis (P-LAM). There is limited evidence that SRL has systemic efficacy for the patients with extrapulmonary lymphangioleiomyomatosis (E-LAM) remaining after lung transplantation (LT) for P-LAM. This report examines the efficacy of SRL treatment for the patient with E-LAM remaining after an LT for P-LAM.

CASE SUMMARY

The course of the patient's recovery from an LT for P-LAM was complicated by lymphedema in the left femoral region that was caused by two E-LAM lesions remaining in the left pelvic cavity and in the retroperitoneal area. After the LT was performed, the patient started SRL treatment to reduce the E-LAM lesions. The daily SRL dose, selected based on the standard SRL dose for P-LAM, was initiated at 1 mg/d and was maintained at 2 mg/d. The remaining E-LAM lesions and lymphedema in the left femoral region improved in approximately 9 months after the LT with the administration of both SRL and the standard immunosuppressive therapy used by Okayama University Hospital, including tacrolimus, mycophenolate mofetil, and prednisolone. The SRL and tacrolimus trough concentrations in whole blood were maintained within the therapeutic window for the next 1.5 years after initiation of SRL treatment. The patient experienced no severe adverse events that required discontinuation of the SRL treatment during this time.

CONCLUSION

The patients with remaining E-LAM lesions may receive SRL treatment to improve the quality of life after LT for P-LAM as effective therapy in cases where the patient's recovery is complicated by E-LAM lesions.

Lung Transplantation for Lymphangioleiomyomatosis in a Single Japanese Institute, With a Focus on Late-onset Complications

BACKGROUND

Although late-onset complications are important factors related to inadequate outcomes of lung transplantation (LTx), little is known about them. The results of LTx for lymphangioleiomyomatosis (LAM) patients, which is a large cohort of LTx recipients in Japan, especially with late-onset complications, are reported.

METHODS

Thirteen consecutive LTx cases with LAM at our institute were evaluated, and those with late-onset complications were identified.

RESULTS

The 5-year survival rate was 69.2%. There were 4 cases with late-onset complications. Case 1: A 35-year-old woman who underwent right single LTx and sustained uncontrollable massive chylous ascites. She underwent placement of a peritoneal-venous shunt, and the ascites was controlled. Unfortunately, she died of small cell cervical cancer (SCCC) 43 months after the LTx. Case 2: A 50-year-old woman who underwent left single LTx had pneumothorax of the native lung 16 months after the LTx. She underwent operative repair of the right lung with a polyglycolic acid (PGA) sheet. She had no recurrence of pneumothorax 1 year after the operation. Case 3: A 33-year-old woman, who underwent left single LTx, had recurrence of LAM in the transplanted lung 2 years after the LTx. She was started on sirolimus. Case 4: A 47-year-old woman, who underwent right single LTx, developed repeated high fevers. She developed an acute abdomen, and swollen subcutaneous lymph nodes were found. After lymph node biopsy, she was diagnosed as having post-transplant lymphoproliferative disorder, and she died 8 months after the LTx.

CONCLUSION

It is hoped that these reports and the knowledge gained from them help improve the outcomes of LTx recipients.

Lung Transplantation for Lymphangioleiomyomatosis in Japan

Background

Lung transplantation has been established as the definitive treatment option for patients with advanced lymphangioleiomyomatosis (LAM). However, the prognosis after registration and the circumstances of lung transplantation with sirolimus therapy have never been reported.

Methods

In this national survey, we analyzed data from 98 LAM patients registered for lung transplantation in the Japan Organ Transplantation Network.

Results

Transplantation was performed in 57 patients as of March 2014. Survival rate was 86.7% at 1 year, 82.5% at 3 years, 73.7% at 5 years, and 73.7% at 10 years. Of the 98 patients, 21 had an inactive status and received sirolimus more frequently than those with an active history (67% vs. 5%, p<0.001). Nine of twelve patients who remained inactive as of March 2014 initiated sirolimus before or while on a waiting list, and remained on sirolimus thereafter. Although the statistical analysis showed no statistically significant difference, the survival rate after registration tended to be better for lung transplant recipients than for those who awaited transplantation (p = 0.053).

Conclusions

Lung transplantation is a satisfactory therapeutic option for advanced LAM, but the circumstances for pre-transplantation LAM patients are likely to alter with the use of sirolimus.

Successful management of bilateral refractory chylothorax after double lung transplantation for lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a rare disease that leads to airways and lymphatic channels obstruction due to abnormal smooth muscle proliferation. It presents with dyspnea, pneumothorax or chylothorax. Lung transplantation (LT) has emerged as a valuable therapeutic option with limited reports. We report a case of LAM that underwent double LT and complicated by refractory bilateral chylothorax which was managed successfully by povidone-iodine pleurodesis and the addition of sirolimus to the post-transplantation immunosuppressive therapy. The patient has no recurrence with 24 months follow-up.

"Malignant" perivascular epithelioid cell neoplasm: risk stratification and treatment strategies

Purpose. Perivascular epithelioid cell tumors (PEComas) are a rare collection of tumors characterized by a myomelanocytic phenotype, and PEComas occurring in “nonclassic” anatomic distributions are known as perivascular epithelioid cell tumor not otherwise specified (PEComa-NOS). This review aims to compile and analyze cases of PEComa-NOS in an effort to better define their natural history. Design. We evaluated all 234 cases of PEComa-NOS reported in the English literature, extracting information regarding diagnostic features, treatment approaches, and outcomes. Multivariate analysis of a number of variables evaluable on pathologic review was performed to refine preexisting risk stratification criteria. Outcomes for patients receiving nonsurgical treatment are also reported. Results. Primary tumor size ≥5 cm (P = 0.02) and a high (1/50 HPF) mitotic rate (P < 0.0001) were the only factors significantly associated with recurrence following surgical resection. Cytotoxic chemotherapy and radiation therapy have shown little benefit in treating PEComa-NOS; mTOR inhibition is emerging as a treatment option. Conclusion. Progress has been made in understanding the natural history and molecular biology of PEComa-NOS. This review further clarifies risk of recurrence in this disease, allowing clinicians to better risk stratify patients. Further work should focus on applying this knowledge to making treatment decisions for patients with this disease.

Current management of lymphangioleiomyomatosis

PURPOSE OF REVIEW

Lymphangioleiomyomatosis (LAM) is a rare but devastating disease, leading to chronic respiratory failure. Considerable progress for comprehension of the disease has been made when mutations of the tuberous sclerosis genes TSC1 and TSC2, were discovered in LAM cells. Therapeutic consequences of these studies are important, leading to clinical trials with sirolimus for LAM.

RECENT FINDINGS

In two studies, angiomyolipoma size decreased by 26-50% after 12 months of sirolimus treatment. In a recent 12 months controlled trial involving 89 patients with pulmonary LAM, sirolimus stopped lung function decline and improved quality of life and performance score. The protective effect of sirolimus was lost after treatment discontinuation, with a parallel lung function decline in both groups, similar to the increase in angiomyolipoma size. Sirolimus is associated with an excess of adverse events.

SUMMARY

Sirolimus represents an important drug for LAM that should be proposed to patients with a rapid alteration of lung function or with a significant clinical impairment, after individual evaluation of the risk/benefit ratio. Sirolimus seems to have a sharper effect on the reduction of abdominal masses than on lung cysts. Tolerance and safety concerns are serious limits to the long-term treatment of patients with sirolimus.

Targeting the dysregulated mammalian target of rapamycin pathway in organ transplantation: killing 2 birds with 1 stone

Dysregulation and hyperactivation of the mammalian target of rapamycin (mTOR) pathway define the molecular basis of the hamartoma syndromes, including Cowden syndrome, tuberous sclerosis complex (TSC)/lymphangioleiomyomatosis, and Peutz-Jeghers syndrome. Loss of the tumor suppressors phosphatase and tensin homolog (PTEN), TSC1, TSC2, and LKB1 results in uncontrolled growth of usually benign tumors in various organs that, however, frequently lead to organ failure. Therefore, organ transplantation is a common therapeutic option in distinct patients with hamartoma syndromes, especially those with TSC/lymphangioleiomyomatosis. mTOR inhibitors are currently used in allogeneic transplantation as immunosuppressants and for the treatment of a growing number of cancers with dysregulated mTOR/phosphoinositide 3-kinase pathway. This dual targeting provides the unique opportunity for mTOR inhibitors to affect hamartoma syndromes at the molecular level along with potent immunosuppression in transplanted individuals. Here, we review the molecular mechanisms of hamartoma syndromes and discuss the recent clinical progress in transplant patients with hamartomas. Combining the identification of novel molecular targets of the phosphoinositide 3-kinase/mTOR pathway with insights into the clinical effectiveness of current therapeutic strategies sets the stage for a broader translational potential essential for further progress both in the treatment of cancer and for transplantation.

Disease-specific approach to lung transplantation

PURPOSE OF REVIEW

The present review provides an update on the recent literature regarding disease-specific issues in lung transplantation. Some of the published data will help refine previously published candidate selection criteria and provide evidence-based data for choice of procedures.

RECENT FINDINGS

Recent studies on lung transplant outcomes in older patients underline that satisfactory results can be obtained in patients older than 60 years but not in patients older than 70 years. Data from two large registry-based studies indicate that bilateral lung transplantation in patients with chronic obstructive pulmonary disease confers significantly longer survival than single lung transplantation, especially in patients younger than 60 years. Mathematical models to estimate survival benefit in chronic obstructive pulmonary disease lung transplant candidates have been developed and are being validated. The impact of Bcc colonization in cystic fibrosis patients on outcome has been nuanced; thus, cystic fibrosis lung transplant candidates colonized by particular Bcc strains may be transplanted with good outcomes. Novel surgical approaches to peculiar situations in end-stage cystic fibrosis have been described. Candidate selection criteria for retransplantation procedures have further been clarified.

SUMMARY

This article attempts to provide an overview of some of the currently important topics for clinicians involved in referring and evaluating patients with end-stage lung disease for lung transplantation in 2009.

Sirolimus inhibits cell proliferation and downregulates mTOR and HIF-1α expression in human hepatic carcinoma HepG2 cells

AIM: To investigate the inhibitory effects of sirolimus on cell proliferation and mammalian target of rapamycin (mTOR) and hypoxia inducible factor-1α (HIF-1α) expression in human hepatic carcionoma HepG2 cells, and explore the potential mechanisms involved in the therapeutic effects of sirolimus against hepatic carcinoma.

METHODS: HepG2 cells were cultured under hypoxic conditions. Different concentrations of sirolimus (0.1-1000 nmol/L) were incubated with HepG2 cells for 24 h. Cell proliferation was measured by methyl thiazolyl tetrazolium (MTT) assay. The expression of mTOR and HIF-1α proteins was determined by Western blot.

RESULTS: Sirolimus could significantly inhibit the proliferation of HepG2 cells in a concentration-dependent manner (all P< 0.05). The expression levels of mTOR and HIF-1α proteins were significantly lower in sirolimus-treated HepG2 cells than in untreated cells (both P < 0.05).

CONCLUSION: Sirolimus exerts anticancer activity possibly by downregulating HIF-1α expression and inducing apoptosis in HepG2 cells under hypoxia conditions via a mechanim dependent on the mTOR signaling pathway.