Identifying trajectories of fatigue in patients with primary mitochondrial disease due to the m.3243A > G variant.

Severe fatigue is a common complaint in patients with primary mitochondrial disease. However, less is known about the course of fatigue over time. This longitudinal observational cohort study of patients with the mitochondrial DNA 3243 A>G variant explored trajectories of fatigue over 2 years, and characteristics of patients within these fatigue trajectories. Fifty-three adult patients treated at the Radboud University Medical Center Nijmegen were included. The majority of the patients reported consistent, severe fatigue (41%), followed by patients with a mixed pattern of severe and mild fatigue (36%). Then, 23% of patients reported stable mild fatigue levels. Patients with a stable high fatigue trajectory were characterized by higher disease manifestations scores, more clinically relevant mental health symptoms, and lower psychosocial functioning and quality of life compared to patients reporting stable low fatigue levels. Fatigue at baseline and disease manifestation scores predicted fatigue severity at the 2-year assessment (57% explained variance). This study demonstrates that severe fatigue is a common and stable complaint in the majority of patients. Clinicians should be aware of severe fatigue in patients with moderate to severe disease manifestation scores on the Newcastle Mitochondrial Disease Scale, the high prevalence of clinically relevant mental health symptoms and overall impact on quality of life in these patients. Screening of fatigue and psychosocial variables will guide suitable individualized treatment to improve the quality of life.

Monoclonal gammopathy of renal significance presenting with cryoglobulinaemia type I associated severe thrombotic microangiopathy.

We report a 53-year-old man who presented with acute renal failure. His medical history revealed a spondyloarthropathy, for which secukinumab was started recently, and a monoclonal gammopathy of unknown significance. Kidney function deteriorated despite the withdrawal of secukinumab and dialysis was started. In the serum, type 1 cryoglobulins were present and a kidney biopsy showed ischaemic glomeruli, with thrombosis of the larger interlobular arteries. Other causes of thrombotic microangiopathy were excluded. Bone marrow immunophenotyping showed 1% monoclonal plasma cells. A diagnosis of monoclonal gammopathy of renal significance was made. Haematological treatment resulted in haematological and renal response.

Cognitive functioning and mental health in mitochondrial disease: A systematic scoping review.

Mitochondrial diseases (MDs) are rare, heterogeneous, hereditary and progressive in nature. In addition to the serious somatic symptoms, patients with MD also experience problems regarding their cognitive functioning and mental health. We provide an overview of all published studies reporting on any aspect of cognitive functioning and/or mental health in patients with MD and their relatives. A total of 58 research articles and 45 case studies were included and critically reviewed. Cognitive impairments in multiple domains were reported. Mental disorders were frequently reported, especially depression and anxiety. Furthermore, most studies showed impairments in self-reported psychological functioning and high prevalence of mental health problems in (matrilineal) relatives. The included studies showed heterogeneity regarding patient samples, measurement instruments and reference groups, making comparisons cautious. Results highlight a high prevalence of cognitive impairments and mental disorders in patients with MD. Recommendations for further research as well as tailored patientcare with standardized follow-up are provided. Key gaps in the literature are identified, of which studies on natural history are of highest importance.

Psychological functioning in children suspected for mitochondrial disease: the need for care.

BACKGROUND: Mitochondrial diseases (MD) are generally serious and progressive, inherited metabolic diseases. There is a high comorbidity of anxiety and depression and limitations in daily functioning. The complexity and duration of the diagnostic process and lack of knowledge about prognosis leads to uncertainty. In this study, we investigated the psychological well-being of children who are suspected for MD and their parents. METHODS: In total 122 children suspected for MD and their parents, received questionnaires as part of standard clinical investigation. RESULTS: Parent proxy report revealed a lower quality of life (QoL) compared to norms and even more physical problems compared to chronically ill patients. They also reported more behavioral problems in general and more internalizing problems compared to the norms. Most frequent reported somatic complaints were tiredness and pain. Parents did not report enhanced levels of stress regarding parenting and experienced sufficient social support. At the end of the diagnostic process, 5.7% of the children received the genetically confirmed diagnosis of MD, 26% showed non-conclusive abnormalities in the muscle biopsy, 54% did not receive any diagnosis, and the remaining received other diagnoses. Strikingly, children without a diagnosis showed equally QoL and behavioral problems as children with a diagnosis, and even more internalizing problems. CONCLUSIONS: This study highlights the psychological concerns of children with a suspicion of MD. It is important to realize that as well as children with a confirmed diagnosis, children without a diagnosis are vulnerable since explanation for their complaints is still lacking.

Sympathetic hyperactivity and clinical outcome in chronic kidney disease patients during standard treatment.

BACKGROUND: Sympathetic hyperactivity has been associated with adverse clinical outcome and is common in patients with chronic kidney disease (CKD). Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) have been shown to reduce sympathetic activity in CKD patients. The present study was performed to investigate whether sympathetic hyperactivity was related to clinical outcome in CKD patients treated with ACEi or ARB. METHODS: Muscle sympathetic nerve activity (MSNA) was measured in 66 nondiabetic patients (70% men) with CKD, median age 47 years (range 21-65) and mean estimated glomerular filtration rate (eGFR) 39+/-29 ml/min per 1.73 m2. Patients were followed up for a median 78 months (range 6-123), and subsequent clinical events were recorded. RESULTS: During follow-up, average blood pressure was 131+/-11 mm Hg systolic and 83+/-6 mm Hg diastolic. Twenty-one events (4 deaths and 17 nonfatal cardiovascular events) occurred in 16 patients. MSNA among the group with events was 40+/-18 bursts/min, compared with 30+/-11 bursts/min in those with no events (p=0.009). An increase of MSNA of 10 bursts/min was related to an increased risk of an event (hazard ratio=1.6; 95% confidence interval, 1.0-2.8; p=0.08), independent of GFR and blood pressure. Age attenuated this relation. CONCLUSION: Sympathetic hyperactivity was associated with the composite of all-cause mortality and nonfatal cardiovascular events in CKD patients, despite treatment with ACEi or ARB. Further studies to investigate potential effects of additional sympatholytic therapy in these patients are warrented.

Different effects of tacrolimus and cyclosporine on renal hemodynamics and blood pressure in healthy subjects.

BACKGROUND: The side effects of cyclosporine, nephrotoxicity and hypertension, contribute to long-term renal graft failure and cardiovascular morbidity in graft recipients. It is not clear whether tacrolimus is as nephrotoxic and hypertensive as cyclosporine. Data on this subject are not consistent because of differences in dosage and duration of treatment and the presence of comorbidity in the studied patients. A comparison of both drugs with respect to renal hemodynamics and blood pressure has not been performed yet in healthy subjects. METHODS: We studied blood pressure, glomerular filtration rate, and effective renal plasma flow in eight healthy subjects at baseline and after 2 weeks administration of cyclosporine and tacrolimus, in randomized order. Trough levels of either drug were within the currently recommended therapeutical range of 100-200 ng/ml for cyclosporine and 5-15 ng/ml for tacrolimus. RESULTS: Tacrolimus did not influence renal hemodynamic parameters, in contrast to cyclosporine. During cyclosporine, glomerular filtration rate decreased from 98+/-9 ml/min/1.732 to 85+/-10 ml/min/1.732 (P<0.05), and ERPF decreased from 597+/-108 ml/min/1.732 to 438+/-84 ml/min/1.732 (P<0.01). Mean arterial blood pressure increased from 93+/-8 mmHg to 108+/-10 mmHg (P<0.05) during cyclosporine and remained unchanged during tacrolimus. CONCLUSIONS: We conclude that tacrolimus given during 2 weeks in the currently advised dosage has no unfavorable effects on renal hemodynamics and blood pressure in healthy individuals. The use of tacrolimus in organ transplant recipients may in the long-term lead to better renal function and less cardiovascular morbidity than the use of cyclosporine.

Differential effects of acute and sustained cyclosporine and tacrolimus on sympathetic nerve activity.

BACKGROUND: We studied the effect of acute and sustained cyclosporine and tacrolimus on muscle sympathetic nerve activity (MSNA) in groups of healthy male volunteers. METHODS AND RESULTS: Acute cyclosporine in normal dose (2.5 mg/kg) increased MSNA from 11 +/- 6 to 19 +/- 8 bursts/min (P < 0.05). Acute cyclosporine in high dose (10 mg/kg) increased MSNA from 13 +/- 6 to 25 +/- 4 bursts/min (P < 0.05) and increased heart rate and mean arterial pressure (heart rate from 64 +/- 8 to 74 +/- 6 b.p.m., MAP from 92 +/- 10 to 105 +/- 8 mmHg; both P < 0.05). Sustained cyclosporine (2.5 mg/kg b.i.d. for 2 weeks) suppressed MSNA from 14 +/- 6 to 8 +/- 7 bursts/min (P < 0.05). Blood pressure increased from 89 +/- 6 to 98 +/- 6 mmHg (P < 0.05). Body weight increased and plasma renin activity was suppressed. Acute tacrolimus in regular dose (0.05 mg/kg) and high dose (0.20 mg/kg) had no effect on MSNA and blood pressure. Sustained tacrolimus (0.05 mg/kg b.i.d. for 2 weeks) had no effect on blood pressure, body weight and plasma renin activity, but decreased MSNA from 14 +/- 6 to 8 +/- 5 bursts/min (P < 0.05). CONCLUSION: Sympathetic overactivity plays a role in the acute hypertensive action of cyclosporine. Cyclosporine given during 2 weeks increases blood pressure and suppresses MSNA, possibly by volume retention. Tacrolimus, in the presently applied dosages, does not cause hypertension or sympathetic overactivity. However, sustained tacrolimus also suppresses sympathetic activity, the reason of which is unclear.

Sympathetic hyperactivity in hypertensive chronic kidney disease patients is reduced during standard treatment.

Standard treatment in chronic kidney disease (CKD) patients includes an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker. CKD is often characterized by sympathetic hyperactivity. This study investigates the prevalence of sympathetic hyperactivity (quantified by assessment of muscle sympathetic nerve activity [MSNA]) in a sizable group of patients with CKD and assessed whether chronic angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker normalizes increased MSNA. In 74 CKD patients (creatinine clearance 54+/-31 mL/min), MSNA, blood pressure, and plasma renin activity were measured in the absence of antihypertensive drugs except for diuretics. In a subgroup of 31 patients, another set of measurements was obtained after > or =6 weeks of enalapril (10 mg PO), losartan (100 mg PO), or eprosartan (600 mg PO). Patients as compared with control subjects (n=82) had higher mean arterial pressure (113+/-13 versus 89+/-7 mm Hg), MSNA (31+/-13 versus 19+/-7 bursts per minute), and log plasma renin activity (2.67+/-036 versus 2.40+/-0.32 fmol/L per second; all P<0.001). During angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker therapy (n=31), mean arterial pressure (115+/-11 to 100+/-9 mm Hg) and MSNA (33+/-11 to 25+/-9 bursts per minute) decreased (both P<0.01) but were still higher than in control subjects (both P<0.01). Multiple regression analysis identified age and plasma renin activity as predictive for MSNA. In conclusion, sympathetic hyperactivity occurs in a substantial proportion of hypertensive CKD patients. Angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment reduces but does not normalize MSNA.

Pathogenesis and treatment of hypertension in polycystic kidney disease.

PURPOSE OF REVIEW: Hypertension is common in patients with autosomal dominant polycystic kidney disease. It may contribute to cardiovascular risk and to progression of renal failure. RECENT FINDINGS: Apart from fluid overload and renin activation, hypertensive patients with autosomal dominant polycystic kidney disease also have increased sympathetic activity, regardless of renal function. Sympathetic hyperactivity not only contributes to the hypertension but may also increase cardiovascular risk independent of blood pressure. SUMMARY: Treatment for normalizing blood pressure and sympathetic activity should be started early in the course of the disease.

Sympathetic hyperactivity in chronic kidney disease: pathogenesis, clinical relevance, and treatment.

Cardiovascular morbidity and mortality importantly influence live expectancy of patients with chronic renal disease (CKD). Traditional risk factors are usually present, but several other factors have recently been identified. There is now evidence that CKD is often characterized by an activated sympathetic nervous system. This may contribute to the pathogenesis of renal hypertension, but it may also adversely affect prognosis independently of its effect on blood pressure. The purpose of this review is to summarize available knowledge on the role of the sympathetic nervous system in the pathogenesis of renal hypertension, its clinical relevance, and the consequences of this knowledge for the choice of treatment.

Sympathetic nerve activity is inappropriately increased in chronic renal disease.

The hypothesis that in hypertensive patients with renal parenchymal disease sympathetic activity is "inappropriately" elevated and that this overactivity is a feature of renal disease and not of a reduced number of nephrons per se is addressed. Fifty seven patients with renal disease (various causes, no diabetes, all on antihypertensive medication) were studied, age range 18 to 62, creatinine clearance 10 to 114 ml/min per 1.73 m(2). Antihypertensives were stopped, but diuretics were allowed, to prevent overhydration. Matched control subjects were also studied. The effect of changes in fluid status was examined in seven patients while on and after stopping diuretics and in eight control subjects while on low- and high-sodium diet. Seven kidney donors were studied before and after unilateral nephrectomy. Sympathetic activity was quantified as muscle sympathetic nerve activity (MSNA) in the peroneal nerve. Mean arterial pressure, MSNA, and plasma renin activity were higher in patients than in control subjects, respectively (115 +/- 12 and 88 +/- 11 mmHg, 31 +/- 15 and 18 +/- 10 bursts/min, and 500 [20 to 6940] and 220 [40 to 980] fmol/L per s; P < 0.01 for all items). Extracellular fluid volume (bromide distribution) did not differ. Seven patients were studied again after stopping diuretics. MSNA decreased from 34 +/- 18 to 19 +/- 18 bursts/min (P < 0.01). Eight healthy subjects were studied during low- and high-sodium diet. MSNA was 26 +/- 12 and 13 +/- 7 bursts/min (P < 0.01). The curves relating extracellular fluid volume to MSNA were parallel in the two groups but shifted to a higher level of MSNA in the patients. In the kidney donors, creatinine clearance reduced by 25%, but MSNA was identical before and after donation. It is concluded that in hypertensive patients with renal parenchymal disease, sympathetic activity is inappropriately high for the volume status and that reduction of nephron number in itself does not influence sympathetic activity.

Sympathetic activity is increased in polycystic kidney disease and is associated with hypertension.

Hypertension is common in patients with polycystic kidney disease (PKD). This study addresses the hypothesis that sympathetic activity is enhanced in hypertensive PKD patients, not only when renal function is impaired but also when renal function is still normal. Muscle sympathetic nerve activity (MSNA, peroneal nerve), plasma renin activity (PRA), heart rate, and BP were studied in PKD patients with normal and with impaired renal function and in matched controls. In hypertensive patients with normal renal function, MSNA and mean arterial pressure (MAP) were higher than in normotensive patients (23 +/- 5 versus 15 +/- 7 bursts/min; 110 +/- 10 versus 90 +/- 3 mmHg; P < 0.05), whereas PRA and heart rate did not differ. In PKD with chronic renal failure (CRF) (creatinine clearance rate, 39 +/- 19 ml/min), MAP, MSNA and PRA were higher than in controls (resp, 116 +/- 7 versus 89 +/- 9 mmHg; 34 +/- 14 versus 19 +/- 9 bursts/min; 405 [20 to 1640] versus 120 [40 to 730] fmol/L per sec; all P < 0.05). Heart rate in PKD CRF did not differ from controls. MSNA correlated with MAP (r = 0.42; P = 0.01) and age with MSNA (r = 0.45; P < 0.01). Regression line of age and MSNA in patients was steeper than that in controls. This study indicates that MSNA is increased in hypertensive PKD patients regardless of renal function. The data support the idea that sympathetic hyperactivity contributes to the pathogenesis of hypertension in PKD.

Enalapril and losartan reduce sympathetic hyperactivity in patients with chronic renal failure.

The aim of this study was to compare the effects on BP and sympathetic activity of chronic treatment with an angiotensin (Ang)-converting enzyme (ACE) inhibitor and an AngII receptor blocker in hypertensive patients with chronic renal failure (CRF). In ten stable hypertensive CRF patients (creatinine clearance, 46 +/- 17 ml/min per 1.73 m(2)), muscle sympathetic nerve activity (MSNA), plasma renin activity (PRA), baroreceptor sensitivity, and 24-h ambulatory BP were measured in the absence of antihypertensive drugs (except diuretics) after 6 wk of enalapril (10 mg orally) and after 6 wk of losartan (100 mg orally). The order of the three phases was randomized. Normovolemia was controlled with diuretics and confirmed with extracellular fluid volume measurements throughout the study. Both enalapril and losartan reduced MSNA (from 33 +/- 10 to 27 +/- 13 and 27 +/- 13 bursts/min, respectively; P < 0.05) and average 24-h BP (from 141 +/- 8/93 +/- 8 to 124 +/- 9/79 +/- 8 and 127 +/- 8/81 +/- 9 mmHg; P < 0.01). PRA was not different during the treatments. The change in BP and the change in MSNA during the treatments were correlated (r = 0.70 and r = 0.63, respectively; both P < 0.05). Baroreceptor sensitivity was not affected by the treatments. This is the first study to compare the effects of ACE inhibition and AngII blockade on MSNA. In hypertensive CRF patients, enalapril and losartan equally reduced BP and MSNA. Differences in modes of action of the two drugs did not result in differences in effects on MSNA, supporting the view that AngII-mediated mechanisms contribute importantly in the pathogenesis of sympathetic hyperactivity in these patients.