Thromboembolic complications in nephrotic syndrome: imaging spectrum

Urinary 8-oxoGuo as a potential novel evaluation index for patients with nephrotic syndrome

Urinary 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2'- deoxyguanosine (8-oxodGuo) are considered biomarkers of oxidative stress, and patients with nephrotic syndrome have been reported to have increased oxidative stress levels. In this study, we aimed to assess the value of 8-oxoGuo and 8-oxodGuo as novel biomarkers to evaluate the severity of nephrotic syndrome. In total, 107 patients with nephrotic syndrome and 116 healthy controls were recruited for this study. The concentrations of urinary 8-oxoGuo and 8-oxodGuo were measured using isotope-labeled liquid chromatography with tandem mass spectrometry. Urinary creatinine was used to regulate 8-oxoGuo and 8-oxodGuo concentrations. Urinary 8-oxoGuo and 8-oxoGuo/Cr levels in patients with nephrotic syndrome were significantly higher than those in healthy control participants. 8-oxoGuo/Cr showed a positive correlation with the 24 h urinary total protein (UTP) and UTP levels and negative correlations with serum total protein and albumin levels. After treatment, urinary 8-oxoGuo and 8-oxoGuo/Cr levels were significantly lower in the group with a low 24 h-UTP value (<3.5 g/d) than in the high value group. 8-oxoGuo can be used as a feasible and reliable biomarker for the assessment of nephrotic syndrome.HighlightsUrinary 8-oxoGuo level was significantly increased in patients with nephrotic syndrome.Urinary 8-oxoGuo level increased with an increase in plasma protein and a decrease in urine protein.Urinary 8-oxoGuo level decreased with nephrotic syndrome remission when urinary microalbumin showed no significant change.Urinary 8-oxoGuo level can be used as novel biomarkers of nephrotic syndrome.

The forgotten urinalysis: an integral part of unmasking thrombophilia

A 43-year-old female presented with flank pain of two days duration. She had been admitted previously for bilateral lower extremity edema which had not improved with diuresis. Abdominal Imaging showed left ovarian vein thrombosis and left renal vein thrombosis extending into the IVC. Chest imaging revealed right lower lobe segmental pulmonary emboli. Careful review of serial urinalysis during previous admissions revealed significant proteinuria. Confirmatory urine tests followed by a renal biopsy led to a diagnosis of membranous nephropathy. We report a case of acute diffuse thromboembolism due to membranous nephropathy, unmasked by serial abnormal urinalysis.

Use of rivaroxaban in a patient with history of nephrotic syndrome and hypercoagulability

OBJECTIVE

Hypercoagulability, resulting in thromboembolic events, can be a life-threatening complication of nephrotic syndrome (NS). Conventional anticoagulants, such as warfarin, have been the standard of care for more than 50 years; however, the availability of target-specific oral anticoagulants (TSOACs) have provided additional options for the treatment and prevention of thromboembolic events. Documented use of the TSOACs in patients with NS and hypercoagulability is currently limited.

CASE SUMMARY

We present the case of an 18-year-old young woman with NS and renal vein thrombosis who was readmitted with bilateral pulmonary emboli on therapeutic doses of warfarin, with a goal international normalized ratio of 2.0 to 3.0. The decision was made to transition the patient from warfarin to rivaroxaban, an oral factor Xa inhibitor.

DISCUSSION

Rivaroxaban was the first of the emerging TSOACs to be FDA approved for both prevention and treatment of venous thromboembolism. With favorable safety and efficacy data compared with warfarin in addition to a predictable pharmacokinetic profile and the lack of requirement of routine monitoring, rivaroxaban provides a useful alternative in this patient population.

SUMMARY

While on therapeutic anticoagulation, a patient previously diagnosed with NS and renal vein thrombosis experienced pulmonary emboli on a conventional anticoagulant and was switched to a target-specific oral anticoagulant with documented completion of 6 months of therapy without recurrent thromboembolism.

Pulmonary embolism and renal vein thrombosis in patients with nephrotic syndrome: prospective evaluation of prevalence and risk factors with CT

PURPOSE

To prospectively determine the prevalence of pulmonary embolism ( PE pulmonary embolism ) and renal vein thrombosis ( RVT renal vein thrombosis ) with computed tomography (CT) and to identify markers predictive of PE pulmonary embolism and/or RVT renal vein thrombosis in a large consecutive cohort of patients with nephrotic syndrome.

MATERIALS AND METHODS

This study was approved by the local institutional review board, and all patients or their guardians provided written informed consent. Consecutive patients with nephrotic syndrome (24-hour urine protein > 3.5 g) underwent combined CT pulmonary angiography for PE pulmonary embolism and renal CT venography for RVT renal vein thrombosis . Prevalence of PE pulmonary embolism and/or RVT renal vein thrombosis was estimated for different ages, sexes, and histopathologic types of nephrotic syndrome. Multivariate analysis was used to determine independent predictors for PE pulmonary embolism and/or RVT renal vein thrombosis in patients with nephrotic syndrome.

RESULTS

There were 512 patients in the study cohort (331 male patients, 181 female patients; mean age, 37 years ± 17 [standard deviation]; range, 9-81 years), including 80 children. One hundred eighty (35%) of 512 patients had PE pulmonary embolism and/or RVT renal vein thrombosis , with PE pulmonary embolism the more common condition (85% [153 of 180]). PE pulmonary embolism was associated with RVT renal vein thrombosis in 85 (56%) of 153 patients and was isolated in 68 patients (44%). Most patients with PE pulmonary embolism (84% [128 of 153]) were asymptomatic. One hundred twelve (22%) of 505 patients had RVT renal vein thrombosis . PE pulmonary embolism and/or RVT renal vein thrombosis was found in 15 (19%) of 80 children with nephrotic syndrome, while 165 (38%) of 432 adult patients with nephrotic syndrome had PE pulmonary embolism and/or RVT renal vein thrombosis (P = .001). Membranous nephropathy was the most common histopathologic type associated with PE pulmonary embolism and/or RVT renal vein thrombosis (48% [88 of 183]). Membranous nephropathy, age greater than 60 years, high hemoglobin level, long prothrombin time, and high creatinine level were independent predictors of PE pulmonary embolism and/or RVT renal vein thrombosis (P < .05 for all).

CONCLUSION

PE pulmonary embolism and RVT renal vein thrombosis are common in patients with nephrotic syndrome. PE pulmonary embolism is more common than RVT renal vein thrombosis , is most often asymptomatic, and is most frequently found in patients with membranous nephropathy. A high index of suspicion and a low threshold for diagnostic work-up is warranted in these patients.

Intracranial hypertension presenting with severe visual failure, without concurrent headache, in a child with nephrotic syndrome

BACKGROUND

Idiopathic intracranial hypertension is a condition typically characterised by headache, normal level of consciousness, papilloedema and raised cerebrospinal fluid pressure. Children often present with visual loss and atypical features of raised pressure, posing a diagnostic and management challenge. A range of renal disorders can predispose to developing this raised intracranial pressure syndrome. We present a case of severe visual failure in a child with nephrotic syndrome, with no headache when elevated pressure was proven. In nephrotic syndrome, visual failure related to elevated intracranial pressures without concurrent headache symptoms has not been reported previously.

CASE PRESENTATION

We discuss a 5-year-old Caucasian girl with steroid sensitive nephrotic syndrome who went on to become a late non-responder and presented with intracranial hypertension. Following initial response to steroids, she had a relapse of her nephrotic syndrome; her proteinuria did not resolve on steroid treatment, requiring addition of cyclosporine therapy to manage her nephrotic syndrome. Three months following this, she presented with visual failure in the right eye with bilateral central scotoma and papilloedema. At the time of presentation of visual impairment, she was otherwise well, with no symptoms of a raised intracranial pressure syndrome or associated systemic illness. Medical management was initiated following confirmation of a raised intracranial pressure. Her intracranial pressure remained elevated requiring serial therapeutic lumbar punctures before some improvement in visual acuity was observed. Later in the clinical course, she presented with worsening of her visual impairment with further deterioration of the vision in the left eye, again associated with elevated intracranial pressure. An urgent surgical cerebrospinal fluid diversion procedure was performed. At review, three years after presentation our patient has severe visual impairment with no perception of light in her right eye and 6/36 Snellen acuity in the left secondary to optic atrophy.

CONCLUSION

Our case demonstrates the occurrence of intracranial hypertension in nephrotic syndrome, highlighting the atypical presentation of severe visual failure without concurrent headache at presentation. This demonstrates the management complexities and the need for clear guidelines for ophthalmological surveillance to aim to reduce permanent visual impairment.