EIF2AK4 mutation in pulmonary veno-occlusive disease: A case report and review of the literature

Pulmonary Veno-Occlusive Disease: A Rare Cause of Pulmonary Hypertension

Pulmonary veno-occlusive disease (PVOD) is a rare entity that is usually mistaken with pulmonary arterial hypertension (PAH) but is considered class I′ of PAH. It is important to subclassify PVOD and distinguish it from PAH as treatment with vasodilators in PVOD patients is controversial and may be fatal. In this article, we describe a case of PVOD and how we diagnosed it.

Novel Molecular Mechanisms of Pulmonary Hypertension: A Search for Biomarkers and Novel Drug Targets-From Bench to Bed Site

Pulmonary hypertension (PH) is defined as increased mean pulmonary artery pressure (mPAP) above 25 mmHg, measured at rest by right heart catheterization. The exact global prevalence of PH is difficult to estimate, mainly due to the complex aetiology, and its spread may be underestimated. To date, numerous studies on the aetiology and pathophysiology of PH at molecular level were conducted. Simultaneously, some clinical studies have shown potential usefulness of well-known and widely recognized cardiovascular biomarkers, but their potential clinical usefulness in diagnosis and management of PH is poor due to their low specificity accompanied with numerous other cardiovascular comorbidities of PH subjects. On the other hand, a large body of basic research-based studies provides us with novel molecular pathomechanisms, biomarkers, and drug targets, according to the evidence-based medicine principles. Unfortunately, the simple implementation of these results to clinical practice is impossible due to a large heterogeneity of the PH pathophysiology, where the clinical symptoms constitute only a common denominator and a final result of numerous crosstalking metabolic pathways. Therefore, future studies, based mostly on translational medicine, are needed in order to both organize better the pathophysiological classification of various forms of PH and define precisely the optimal diagnostic markers and therapeutic targets in particular forms of PH. This review paper summarizes the current state of the art regarding the molecular background of PH with respect to its current classification. Novel therapeutic strategies and potential biomarkers are discussed with respect to their limitations in use in common clinical practice.

Pulmonary vein occlusion and veno-occlusive disease in a bilateral lung transplant patient: A case report

A pulmonary vein occlusion and biopsy proven pulmonary veno-occlusive disease (PVOD) and hemangiomatosis is found in a bilateral lung transplant patient. A 61-year-old male presents with dyspnea and chest pain with minimal exertion at routine follow up on post-transplant day of 50. Chest CT demonstrates new occlusion of bilateral superior pulmonary veins and diffuse pulmonary edema. Pulmonary vein occlusion is confirmed by trans-esophageal echocardiogram, and PVOD and hemangiomatosis is corroborated with lung biopsy. Normal pulmonary capillary wedge pressure (PCWP) and reduced DL_CO are also consistent with PVOD. Vigilant evaluation of large pulmonary venous thrombus is as important as of arterial thrombus in a postsurgical transplant status. A dedicated protocol of pulmonary venous phase scan would be beneficial to identify subtle pulmonary venous abnormalities. Although PVOD/PCH is normally considered in patients with nonspecific PAH symptoms, lacking of direct manifestation of PAH should not dismiss the diagnosis of PVOD/PCH, particularly in lung transplant individuals with large pulmonary vein occlusion, progressive respiratory symptoms, DLCO abnormalities, and pulmonary congestion since it may represent a wide spectrum of occlusive vascular disease.

Genome-wide scan reveals divergent selection among taurine and zebu cattle populations from different regions

In this study, to identify genomic signatures of divergent selection, we genotyped 10 cattle breeds/populations (n = 275), representing eight Ethiopian cattle populations (n = 229) and two zebu populations (n = 46) adapted to tropical and sub-tropical environments, using the high-density single-nucleotide polymorphisms (SNPs) derived mainly from Bos indicus breeds, and using five reference taurine breeds (n = 212). Population genetic differentiation (F_ST ) values across sliding windows were estimated between zebu and reference combined taurine breeds. The most differentiated regions (F_ST  ≥ 0.53), representing the top 1% smoothed F_ST values, were considered to represent regions under diversifying selection. In total, 285 and 317 genes were identified in the comparisons of Ethiopian cattle with taurine and Asian zebu with taurine respectively. Some of these genes are involved in stress responses/thermo-tolerance and DNA damage repair (HSPA4, HSF1, CMPK1 and EIF2AK4), pigmentation (ERBB3 and MYO1A), reproduction/fertility (UBE2D3, ID3 and PSPC1), immune response (PIK3CD and AKIRIN2) and body stature and size (MBP2, LYN and NPM1). Additionally, the candidate genes were associated with functional terms (e.g. cellular response to stress, DNA repair, inflammatory response) important for physiological adaptation to environmental stresses. The results of our study may shed light on the influence of artificial and natural selection in shaping the genomic diversity of modern cattle breeds and also may serve as a basis for further genetic investigation of traits of tropical adaptation in cattle.

A case report of PVOD patient combined with pulmonary embolism: Anticoagulation or not?

RATIONALE

Pulmonary veno-occlusive disease (PVOD) is a rare form of pulmonary arterial hypertension (PAH). Oral anticoagulation is confined to patients with idiopathic PAH (IPAH), but no oral anticoagulation has been recommended for PVOD, because occult pulmonary hemorrhage was a common finding in PVOD.

PATIENT CONCERNS

We report a case of PVOD, who was misdiagnosed as IPAH for 5 years with worsening dyspnea and two episodes of pulmonary embolism (PE).

DIAGNOSES

He was confirmed as PVOD combined with PE by biopsy of the explanted lung specimen.

INTERVENTIONS

He took oral anticoagulation, warfarin, to treat his first-time PE in July 2010, and his disease was kept stable for about 4 years, until he discontinued the anticoagulation therapy by himself sometime in 2014. Later on, a life-threatening PE recurred in January 2015, so he resumed the anticoagulation therapy.

OUTCOMES

Fortunately, the bilateral sequential lung transplantation that was performed in July 2015 in time saved his life. He has been living well without dyspnea and the echocardiography showed the normalizations of the once increased pulmonary arterial pressure and the once enlarged right ventricle of his heart. In addition, to the best of my knowledge, he was the first PVOD patient receiving lung transplantation in China.

LESSONS

We recommend that PVOD patients combined with PE should be treated with anticoagulation therapy indefinitely to prevent the recurrence of life-threatening PE until they get a chance for lung transplantation.