Sirolimus-Induced Diffuse Alveolar Hemorrhage: A Case Report

MEK1/2- and ERK1/2-Mediated Lung Endothelial Injury and Altered Hemostasis Promote Diffuse Alveolar Hemorrhage in Murine Lupus

OBJECTIVE

About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll-like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2-ERK1/2, JNK, p38).

METHODS

B6 and BALB/c mice were treated with pristane with or without inhibitors of MEK1/2 (trametinib/GSK1120212 [GSK]), ERK1/2 (SCH772984 [SCH]), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined.

RESULTS

GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung samples from pristane-treated mice but not in mice receiving pristane and GSK, and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor early growth response 1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi and Thbd in B6 mice. The ratio of Tfpi to tissue factor (F3) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating thrombomodulin protein levels increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice.

CONCLUSION

Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in systemic lupus erythematosus and may help to optimize therapy.

Sirolimus-induced pulmonary hemorrhage of an infant with massive cervicofacial lymphatic malformation: A case report

Lymphatic malformations (LMs) are uncommon congenital abnormalities of the lymphatic system. As more than half of these lesions develop in the head and neck, LMs can be life-threatening if associated with airway involvement. LMs necessitate a multidisciplinary treatment approach, frequently including surgery and sclerotherapy. We present a case report of a 32-week pre-term male infant with a massive cervicofacial LM necessitating delivery via ex-utero intrapartum treatment (EXIT). The patient was treated with numerous rounds of sclerotherapy, systemic sirolimus, and surgical debulking, but ultimately died at 4 months of age due to acute pulmonary hemorrhage, which may have been related to sirolimus due to the absence of any other associable organ involvement or derangement. We document the patient's clinical course and treatment regimen, highlighting the myriad modalities employed to treat these challenging lesions, and describe a potentially lethal complication of sirolimus therapy not previously described in the treatment of pediatric LM.

Trends of rapamycin in survival benefits of liver transplantation for hepatocellular carcinoma

The proportion of liver transplantation (LT) for hepatocellular carcinoma (HCC) has kept on increasing over the past years and account for 20%-40% of all LT. Post-transplant HCC recurrence is considered the most important factor affecting the long-term survival of patients. The use of different types of immunosuppressive agents after LT is closely associated with an increased risk for HCC recurrence. The most commonly used conventional immunosuppressive drugs include the calcineurin inhibitors tacrolimus (FK506) and mammalian target of rapamycin inhibitor rapamycin (RAPA). Compared with tacrolimus, RAPA may carry an advantage in survival benefit because of its anti-tumor effects. However, no sufficient evidence to date has proven that RAPA could increase long-term recurrence-free survival and its anti-tumor mechanism of combined therapy remains incompletely clear. In this review, we will focus on recent advances in clinical application experience and basic research results of RAPA in patients undergoing LT for HCC to further guide the clinical practice.

Causes of Hemoptysis in Renal Transplant Patients

OBJECTIVES

Hemoptysis is a symptom that can be caused by airway disease, pulmonary parenchymal disease, or pulmonary vascular disease, or it can be idiopathic. Infection is the most common cause of hemoptysis, accounting for 60% to 70% of cases. Hemoptysis is also an initial symptom of diffuse alveolar hemorrhage syndrome, although it may be absent at presentation in one-third of patients. Diffuse alveolar hemorrhage is characterized by disruption of the alveolar-capillary basement membranes because of either injury or inflammation of the arterioles, venules, or capillaries, resulting in bleeding in alveolar spaces. To date, no study in the literature has investigated the cause of hemoptysis in renal transplant patients. In this retrospective study, we aimed to investigate the causes of hemoptysis in renal recipients.

MATERIALS AND METHODS

The data included in this study were obtained from 352 renal transplant patients who were consulted by the pulmonology department regarding hemoptysis between 2011 and 2017 at Baskent University. Patient medical records were reviewed for demographic, clinical, radiographic, bronchoscopic features, and microbiology data. Immunosuppressive drugs and clinical outcome data were also noted.

RESULTS

This study included 352 renal transplant patients (139 male patients with mean age of 34.9 ± 7 years and 113 female patients with mean age of 31.1 ± 5 years). Hemoptysis was detected in 17 patients (4.8%),with 3 (0.85%) having massive hemoptysis as a result of diffuse alveolar hemorrhage syndrome. Fourteen of our patient group (4%) had pneumonia, and Aspergillus species was detected in 5 patients (1.4%). The only reason for diffuse alveolar hemorrhage was immunosuppressive agents, including sirolimus and mycophenolate mofetil.

CONCLUSIONS

Hemoptysis is an important respiratory symptom in renal transplant patients. Although community- or hospital-acquired pneumonia may result in hemoptysis, drug-induced diffuse alveolar hemorrhage and Aspergillus infection should be considered for causes in renal transplant patients.