Effect of nusinersen on respiratory function in paediatric spinal muscular atrophy types 1-3

INTRODUCTION

Nusinersen is used in spinal muscular atrophy (SMA) to improve peripheral muscle function; however, respiratory effects are largely unknown.

AIM

To assess the effects of nusinersen on respiratory function in paediatric SMA during first year of treatment.

METHODS

A prospective observational study in paediatric patients with SMA who began receiving nusinersen in Queensland, Australia, from June 2018 to December 2019. Outcomes assessed were the age-appropriate respiratory investigations: spirometry, oscillometry, sniff nasal inspiratory pressure, mean inspiratory pressure, mean expiratory pressure, lung clearance index, as well as polysomnography (PSG) and muscle function testing. Lung function was collected retrospectively for up to 2 years prior to nusinersen initiation. Change in lung function was assessed using mixed effects linear regression models, while PSG and muscle function were compared using the Wilcoxon signed-rank test.

RESULTS

Twenty-eight patients (15 male, aged 0.08-18.58 years) were enrolled: type 1 (n=7); type 2 (n=12); type 3 (n=9). The annual rate of decline in FVC z-score prior to nusinersen initiation was -0.58 (95% CI -0.75 to -0.41), and post initiation was -0.25 (95% CI -0.46 to -0.03), with a significant difference in rate of decline (0.33 (95% CI 0.02 to 0.66) (p=0.04)). Most lung function measures were largely unchanged in the year post nusinersen initiation. The total Apnoea-Hypopnoea Index (AHI) was reduced from a median of 5.5 events/hour (IQR 2.1-10.1) at initiation to 2.7 events/hour (IQR 0.7-5.3) after 1 year (p=0.02). All SMA type 1% and 75% of SMA types 2 and 3 had pre-defined peripheral muscle response to nusinersen.

CONCLUSION

The first year of nusinersen treatment saw reduced lung function decline (especially in type 2) and improvement in AHI.

Relationship between respiratory function and need for NIV in childhood SMA

BACKGROUND

Spinal muscular atrophy (SMA) causes progressive respiratory muscle weakness but respiratory function (RF) in those using noninvasive ventilation (NIV) is not well described.

OBJECTIVE

To describe RF in childhood SMA and assess differences between those using and not using NIV.

METHODS

A cross-sectional study of childhood SMA assessed polysomnography (PSG), spirometry, forced oscillation technique (FOT), lung clearance index (LCI), sniff nasal inspiratory pressures, peak cough flow, maximal inspiratory and expiratory pressure, and NIV use and indication.

RESULTS

Twenty-five children (median age [interquartile range], 8.96 [5.63] years; 10 F) with SMA 1 (n = 3), 2 (n = 15), and 3 (n = 7) were recruited. Spirometry and FOT testing was feasible in children as young as 3 years. Ten (40%) required NIV, 5 for sleep-disordered breathing (SDB), and 5 initiated during lower respiratory tract infection (LRTI). Children requiring NIV were older (median, 10.52 vs 5.67 years; P < .02) with more abnormal forced vital capacity (FVC) z-score (-5.70 vs -1.39, P < .02), Rsr8 z-score (1.97 vs 0.50, P = .04), and LCI (8.84 vs 7.34, P = .01). Two had normal RF and SDB. For FVC z-score less than -2.5 and LCI greater than 7.5, the odds ratio for NIV was 10.70 (95% confidence interval [CI], 1.39-82.03) and 2 (95% CI, 0.40-10.31), respectively. All children with LCI greater than 8 used NIV. FVC z-score and LCI are associated with maximum transcutaneous carbon dioxide on PSG (r = 0.43, P < .001).

CONCLUSION

NIV is common in SMA. Normal RF does not exclude SDB. Children with more abnormal FVC and LCI should be considered at risk of starting NIV during/following an LRTI.

Decoy receptors block TRAIL sensitivity at a supracellular level: the role of stromal cells in controlling tumour TRAIL sensitivity

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death ligand cytokine known for its cytotoxic activity against malignantly transformed cells. TRAIL induces cell death through binding to death receptors DR4 and DR5. The inhibitory decoy receptors (DcR1 and DcR2) co-expressed with death receptor 4 (DR4)/DR5 on the same cell can block the transmission of the apoptotic signal. Here, we show that DcRs also regulate TRAIL sensitivity at a supracellular level and thus represent a mechanism by which the microenvironment can diminish tumour TRAIL sensitivity. Mathematical modelling and layered or spheroid stroma-extracellular matrix-tumour cultures were used to model the tumour microenvironment. By engineering TRAIL to escape binding by DcRs, we found that DcRs do not only act in a cell-autonomous or cis-regulatory manner, but also exert trans-cellular regulation originating from stromal cells and affect tumour cells, highlighting the potent inhibitory effect of DcRs in the tumour tissue and the necessity of selective targeting of the two death-inducing TRAIL receptors to maximise efficacy.

What service users want: a new clinic results service. Can we satisfy both patients' needs and wants?

Many clinics still have a 'no news is good news' (NNIGN) policy for clinic results. We asked our service users their preferences for obtaining results. We also designed a new clinic results service. Patients were invited to complete a service evaluation questionnaire. They were given nine options for obtaining results and asked to rate acceptability on a 1-9 scale (unacceptable to acceptable). Completed questionnaires were compared with the actual method they chose to obtain results for that visit. In all, 1000 questionnaires (561 females, 439 males) were completed. Average acceptability score was highest for mobile phone (7.7), followed by text (5.8) and letter (5.7). NNIGN (3.7) and returning for results (3.6) received the least popular ratings. When compared with the actual method chosen, mobile phone was the most popular (62%) followed by letter (17%). Only 10% of patients found NNIGN acceptable. Following the evaluation we purchased texting software and redesigned our results service. There are now four options for receiving results - texting, letter, patient telephones us and NNIGN. We believe we have been able to satisfy both patients' needs and their wishes by redesigning our service around their views.

Intermittent catheterisation for neuropathic urinary incontinence

Eighty six children with neuropathic urinary incontinence who had been treated by clean intermittent catheterisation for more than five years were reviewed. Eighty five had congenital lesions, and one traumatic paraplegia. During the day, 72 (84%) patients were dry or had minor stress incontinence only, 11 were damp but controlled with pads, and only three were continuously wet. Eleven abandoned clean intermittent catheterisation, five because of poor control, four by choice despite good control, and only two because of deterioration of upper urinary tract disease. Most of them usually had bacteriuria, but only 32 developed occasional symptomatic infections. Urinary calculi occurred in six, epididymitis in three, and urethral problems in four. Upper urinary tract dilatation did not arise in a previously normal renal system in any patient during clean intermittent catheterisation. Clean intermittent catheterisation was successful in controlling wetting with few serious complications, and was well tolerated. It remains the method of choice for the management of neuropathic urinary incontinence in such children.

Symbiotic mutants of Rhizobium meliloti that uncouple plant from bacterial differentiation

Spontaneous mutants at a new symbiotic locus in Rhizobium meliloti SU47 are resistant to several phages and are conditionally insensitive to a monoclonal antibody to the bacterial surface, apparently because they are deficient in a wild-type exopolysaccharide. On alfalfa, the mutants do not curl root hairs, but penetrate the epidermis directly, forming nodules that contain no visible infection threads or "bacteroids," have a few bacteria in superficial intercellular spaces only and not within the nodule cells, and fail to fix nitrogen (Fix-). Evidently, infection threads are not essential for cell proliferation and nodule formation, which are here induced by a bacterial signal at a distance and uncoupled from the bacterial differentiation that normally goes on as well.

Management of neuropathic urinary incontinence in children by intermittent catheterisation

Forty-nine children with urinary incontinence owing to neuropathic bladder were treated by intermittent catheterisation. Manometric studies to determine urethral closing pressures and intravesical pressure/volume relationships were performed before or during treatment in all children. Cystography and intravenous urography were carried out at the beginning of treatment and intravenous urography was repeated after treatment for at least 12 months. Routine long-term antibacterial therapy was not used. With a 3-hourly catheterisation regimen a total of 46 (93%) children achieved day-time control but 27 (55%) did so only with the help of propantheline or imipramine or both of these. Night-time control was also substantially improved in 43 (87%) children. The manometric studies enabled a reliable prediction to be made on whether drugs would be required to achieve success. One child with an undilated urinary tract before treatment developed unilateral dilatation owing to mechanical problems during treatment. Upper urinary tract dilatation which was present before treatment in 20 children (33 kidneys) disappeared or improved in all. Early renal failure in 2 children also responded favourably. The technique had to be abandoned in 2 children.