Screening for neurodegeneration in Langerhans cell histiocytosis with neurofilament light in plasma.

Patients with Langerhans cell histiocytosis (LCH) may develop progressive neurodegeneration in the central nervous system (ND-CNS-LCH). Neurofilament light protein (NFL) in cerebrospinal fluid (CSF) is a promising biomarker to detect and monitor ND-CNS-LCH. We compared paired samples of NFL in plasma (p-NFL) and CSF in 10 patients (19 samples). Nine samples had abnormal CSF-NFL (defined as ≥380 ng/l) with corresponding p-NFL ≥ 2 ng/l. Ten samples had CSF-NFL < 380 ng/l; eight (80%) with p-NFL < 2 ng/l (p < 0.001; Fisher's exact test). Thus, our results suggest that p-NFL may be used to screen for ND-CNS-LCH. Further studies are encouraged, including the role of p-NFL for monitoring of ND-CNS-LCH.

High levels of plasma interleukin-17A are associated with severe neurological sequelae in Langerhans cell histiocytosis.

OBJECTIVE: Langerhans cell histiocytosis (LCH) is a granulomatous inflammatory myeloid neoplasia associated with a cytokine storm in both serum and lesions. Increased levels of plasma interleukin-17A (IL-17A) in LCH patients have been reported, but this finding was not confirmed in all studies. Neurodegeneration is a devastating complication of LCH (ND-LCH). We aimed to revisit the issue of plasma IL-17A levels in LCH, by using a larger number of patients, and also to investigate the relationship between IL-17A and LCH sequelae, especially ND-LCH. METHODS: Plasma samples from 68 LCH patients and 127 controls were analyzed for IL-17A levels by two ELISAs with different anti-IL-17A capture antibodies: either polyclonal or neutralizing monoclonal antibodies in 17polyAb-ELISA or 17mAb-ELISA, respectively. RESULTS: Both ELISAs had a similar capacity to specifically detect recombinant or native human IL-17A, as well as plasma IL-17A from LCH patients. We confirmed the finding of higher levels of plasma IL-17A in LCH patients compared to controls (p < 0.0001). The association of IL-17A with LCH was independent of the ELISA used, and of gender, age, disease class activity, and pattern of tissue-organ involvement (single-system versus multi-system). ROC analyses (p < 0.0001) allow to discriminate LCH patients from the control group, supporting the notion that IL-17A may be a potential biomarker for LCH. More interestingly, high IL-17A levels were significantly associated with LCH patients having sequelae, with the highest plasma levels in patients with ND-LCH (p < 0.0001). CONCLUSION: The association between high levels of IL-17A and LCH was confirmed. IL-17A may be associated with ND-LCH development. This might have therapeutic implications, offering a novel target for precision therapy of ND-LCH.

Tissue-infiltrating neutrophils represent the main source of IL-23 in the colon of patients with IBD.

OBJECTIVE: In IBD, interleukin-23 (IL-23) and its receptor (IL-23R) are implicated in disease initiation and progression. Novel insight into which cells produce IL-23 at the site of inflammation at an early stage of IBD will promote the development of new tools for diagnosis, treatment and patient monitoring. We examined the cellular source of IL-23 in colon tissue of untreated newly diagnosed paediatric patients with IBD. DESIGN: Colon tissues from IBD and non-IBD patients were analysed by quantitative real-time PCR (qPCR), immunofluorescence confocal microscopy and flow cytometry after appropriate sample preparation. Blood samples from IBD and non-IBD patients and healthy controls were analysed using flow cytometry and qPCR. RESULTS: We discovered that tissue-infiltrating neutrophils were the main source of IL-23 in the colon of paediatric patients with IBD, while IL-23(+) human leucocyte antigen-DR(+) or IL-23(+)CD14(+) cells were scarce or non-detectable, respectively. The colonic IL-23(+) neutrophils expressed C-X-C motif (CXC)R1 and CXCR2, receptors for the CXC ligand 8 (CXCL8) chemokine family, and a corresponding CXCR1(+)CXCR2(+)IL-23(+)subpopulation of neutrophils was also identified in the blood of both patients with IBD and healthy individuals. However, CXCL8-family chemokines were only elevated in colon tissue from patients with IBD. CONCLUSIONS: This study provides the first evidence of CXCR1(+)CXCR2(+)IL-23-producing neutrophils that infiltrate and accumulate in inflamed colon tissue of patients with IBD. Thus, this novel source of IL-23 may play a key role in disease progression and will be important to take into consideration in the development of future strategies to monitor, treat and prevent IBD.

Detection of IL-17A-producing peripheral blood monocytes in Langerhans cell histiocytosis patients.

Langerhans cell histiocytosis (LCH) is a rare disease of unknown cause with manifestations ranging from isolated granulomatous lesions to life-threatening multi-system organ involvement. This disorder is further characterized by infiltration of immune cells in affected tissues and an association with interleukin (IL)-17A has been reported. Here, we investigated the presence of IL-17A-producing cells among peripheral blood mononuclear cells isolated from LCH patients and observed a high percentage of IL-17A(+) monocytes in peripheral blood of LCH patients compared to controls. The IL-17A(+) monocytes were also positive for the transcription factor retinoic acid orphan receptor (ROR) γt and showed increased mRNA levels for both IL-17A and RORγt. Notably, IL-17A was produced by all monocyte subsets and the expression level was positively associated with LCH disease activity. These data support a role for monocytes in the pathogenesis of LCH. Future therapeutic approaches may consider identification of patients who may benefit from IL-17A-targeted interventions.

Self-rated physical loads of work tasks among firefighters.

OBJECTIVES: The present study sought to identify firefighters' rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters. METHODS: An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category. RESULTS: Significant differences were seen between the full- and part-time firefighters. The work tasks rated as the most physically strenuous in terms of aerobic fitness, muscle strength, work posture and body control by most respondents were smoke diving upstairs (carrying a hose), victim rescue in different ways, carrying a stretcher over terrain and pulling a hose. CONCLUSIONS: Physically strenuous work tasks should be included in the end-point performance variables used to select physical performance tests for firefighters. The part-time firefighters with no experience in several of the work tasks suggests that work-related exercises are important if both groups of firefighters are expected to do similar work.

Langerhans cell histiocytosis in children born 1982-2005 after in vitro fertilization.

AIM: In a recent Swedish study, comparing data from the Swedish Cancer Register with the Medical Birth Register including data on IVF, an increased risk of Langerhans cell histiocytosis (LCH) was found in children born 1982-2005 after IVF. Here, we aimed to verify the LCH diagnoses and examine whether any special forms of the disease were overrepresented in this population. METHODS: Medical records for all children with LCH conceived by IVF were acquired and the diagnosis confirmed or discarded. Disease characteristics were compared with data from children diagnosed with LCH 1992-2001 in the Stockholm County. RESULTS: We verified LCH in seven children born after IVF, all born prior to 2002. These children did not have milder disease forms. The odds ratio (OR) to develop LCH for the whole group born after IVF was 3.2 [95% confidence interval (CI), 1.4-7.3] and for children born before 2002, 5.2 [95% CI, 2.3-11.9], compared with children in Stockholm County 1992-2001. CONCLUSION: LCH was overrepresented in children born after IVF prior to 2002. Affected children did not have milder disease forms. These findings may be valuable to understand LCH aetiology. Additional studies on a putative correlation between IVF and LCH in the offspring are encouraged.

The need for worldwide policy and action plans for rare diseases.

UNLABELLED: There are more than 6000 rare diseases (defined as affecting <5/10 000 individuals in Europe, <200 000 people in the United States). The rarity can create problems including: difficulties in obtaining timely, accurate diagnoses; lack of experienced healthcare providers; useful, reliable and timely information may be hard to find; research activities are less common; developing new medicines may not be economically feasible; treatments are sometimes very expensive; and in developing countries, the problems are compounded by other resource limitations. Emphasis is required to support appropriate research and development leading to better prevention, diagnosis and treatments of rare diseases. Notably, clinical trials using already existing drugs may result in new, affordable, treatment strategies. Moreover, rare diseases may teach us about common disorders. CONCLUSIONS: Countries are encouraged to implement specific research and development activities within their individual capabilities, so that patients worldwide have equal access to necessary interventions to maximize the potential of every individual.

Incidence and pattern of radiological central nervous system Langerhans cell histiocytosis in children: a population based study.

BACKGROUND: Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and other central nervous system (CNS) dysfunctions revealed by brain magnetic resonance imaging (MRI). We estimated the incidence and pattern of pathological brain MRI findings in a well-defined, population-based cohort of children with LCH. METHODS: Among children under 15 years of age diagnosed with LCH in the Stockholm County during 1992-2001, brain MRI was performed at a single center in children with clinical and/or laboratory signs of CNS involvement, including endocrine dysfunction. RESULTS: Out of the 29 children (16 males, 13 females) diagnosed with LCH, brain MRI was performed based on clinical indications in 16 children (55%) with either abnormal endocrine findings (n = 6), such as diabetes insipidus (n = 5), low IGF-1 (n = 1), or panhypopituitarism (n = 1), or clinical CNS symptoms (n = 10). CNS MRI abnormalities were demonstrated in eight children (28%), at a median time of 3.5 years after LCH diagnosis (range 1-11.4 years). Altogether 7 of the 29 children (24%) had MRI findings associated with neurodegeneration, corresponding to a minimal incidence of 2.1/10(6) children per year. Neurodegenerative abnormalities tended to be more frequent in patients with craniofacial involvement (P = 0.12). CONCLUSIONS: The minimal annual incidence rate of neurodegenerative associated radiographic findings in LCH is estimated at 2.1/10(6) children (24% of all children with LCH). An important question is whether all patients with LCH, or certain forms of LCH, should be recommended for a late follow-up examination including MRI. In patients with CNS-LCH, neurological, neuropsychological, neurophysiological, neurochemical and neuroradiological follow-up assessment is suggested.

Fifteen years of treatment with intravenous immunoglobulin in central nervous system Langerhans cell histiocytosis.

AIM: There is currently no well-accepted therapy for central nervous system Langerhans cell histiocytosis (CNS-LCH), a neuroinflammatory disease clinically characterized by often progressive, neurological symptoms including ataxia, dysarthria, dysphagia, hypertonicity, intellectual impairment and behavioural abnormalities. We applied immunomodulative/anti-inflammatory treatment on a patient with progressive CNS-LCH disease. METHOD: Intravenous immunoglobulin (IVIG) was administered monthly for 15 years to a patient with severe, image-verified neurodegenerative CNS-LCH. RESULTS: During the IVIG treatment, the neurological deterioration initially appeared to be haltered, but over time there was still some deterioration. CONCLUSIONS: IVIG may be beneficial in partly haltering CNS-LCH neurodegeneration, but further studies are needed.

Neutralizing Anti-IL-17A Antibody Demonstrates Preclinical Activity Enhanced by Vinblastine in Langerhans Cell Histiocytosis.

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm characterised by the accumulation into granulomas of apoptosis-resistant pathological dendritic cells (LCH-DCs). LCH outcome ranges from self-resolving to fatal. Having previously shown that, (i) monocyte-derived DCs (Mo-DCs) from LCH patients differentiate into abnormal and pro-inflammatory IL-17A-producing DCs, and (ii) recombinant IL-17A induces survival and chemoresistance of healthy Mo-DCs, we investigated the link between IL-17A and resistance to apoptosis of LCH-DCs. In LCH granulomas, we uncovered the strong expression of BCL2A1 (alias BFL1), an anti-apoptotic BCL2 family member. In vitro, intracellular IL-17A expression was correlated with BCL2A1 expression and survival of Mo-DCs from LCH patients. Based on the chemotherapeutic drugs routinely used as first or second line LCH therapy, we treated these cells with vinblastine, or cytarabine and cladribine. Our preclinical results indicate that high doses of these drugs decreased the expression of Mcl-1, the main anti-apoptotic BCL2 family member for myeloid cells, and killed Mo-DCs from LCH patients ex vivo, without affecting BCL2A1 expression. Conversely, neutralizing anti-IL-17A antibodies decreased BCL2A1 expression, the downregulation of which lowered the survival rate of Mo-DCs from LCH patients. Interestingly, the in vitro combination of low-dose vinblastine with neutralizing anti-IL-17A antibodies killed Mo-DCs from LCH patients. In conclusion, we show that BCL2A1 expression induced by IL-17A links the inflammatory environment to the unusual pro-survival gene activation in LCH-DCs. Finally, these preclinical data support that targeting both Mcl-1 and BCL2A1 with low-dose vinblastine and anti-IL-17A biotherapy may represent a synergistic combination for managing recurrent or severe forms of LCH.

Comparison of three different ELISAs for the detection of recombinant, native and plasma IL-17A.

Plasma IL-17A detection in Langerhans Cell Histiocytosis (LCH) is currently a source of debate. Indeed, 500-P07G (PeproTech) and 41802 (R&D Systems) anti-IL-17A antibodies have been suspected to recognize nonspecific proteins. To resolve this discrepancy, we set up two new ELISAs by using 41802 or neutralizing eBio64CAP17 (eBioscience) capture monoclonal antibodies that we compared to the commercial PeproTech ELISA kit. The three ELISAs, called E_500-P07G, E_41802 and E_eBio64CAP17, differ in their anti-IL-17A capture antibodies: either polyclonal, monoclonal or neutralizing monoclonal antibodies, respectively. Here, we show that these ELISAs had a similar capacity to specifically detect recombinant or native human IL-17A. However, a significantly lower plasma IL-17A detection was obtained with E_41802 compared to the two other ELISAs. Both E_500-P07G and E_eBio64CAP17 showed similar results. Consequently, we propose that the use of E_500-P07G and E_eBio64CAP17 may ensure more accurate and reliable results in the context of LCH studies. The highest plasma IL-17A levels in LCH patients compared to controls detected by both E_500-P07G and E_eBio64CAP17 ELISAs led us to propose these latter as reference techniques to investigate IL-17A as a potential new biomarker in LCH.•The customization of a new E_eBio64CAP17 ELISA is suitable to detect human IL-17A.•E_eBio64CAP17 ELISA protocol differs only in the anti-IL-17A capture antibody compared to the commercial E_500-P07G PeproTech kit.•Data generated using the E_eBio64CAP17 ELISA are consistent with the PeproTech kit.

Biomarkers in the cerebrospinal fluid and neurodegeneration in Langerhans cell histiocytosis.

BACKGROUND: Progressive neurodegeneration may result in potentially severe cognitive and motor dysfunctions as a complication of Langerhans cell histiocytosis (LCH), a suggested IL-17A-associated inflammatory condition. To detect this complication (CNS-LCH) early and to evaluate the potential efficacy of therapeutic interventions, biomarkers detecting and measuring ongoing neurodegeneration would be valuable. We evaluated cerebrospinal fluid (CSF) biomarkers of ongoing neurodegeneration in CNS-LCH patients. PROCEDURE: Nine patients with endocrine, neuromotor, cognitive or/and behavioral abnormalities as well as neuroradiological evidence of CNS-LCH were evaluated 4-12 years after LCH diagnosis for CSF levels of neurofilament protein light chain (NF-L), glial fibrillary acid protein (GFAp), and total tau protein (TAU). Two patients were analyzed longitudinally. One hundred ten children with newly diagnosed acute lymphoblastic leukemia (ALL) served as controls. RESULTS: NF-L, TAU, and GFAp levels were elevated in four, six, and eight of nine patients studied, respectively. NF-L (P < 0.001) and GFAp (P < 0.001) were higher in patients than in controls (TAU not analyzed in controls). The patient with most severe clinical and neuroradiological CNS-LCH displayed the highest levels of NF-L and GFAp whereas three patients without signs of systemic disease had low TAU levels and normal/slightly elevated NF-L. NF-L tended to be higher at radiological progression of neurodegeneration than at status quo (P = 0.07). Notably, we experienced frequent lumbar puncture complications in these patients. CONCLUSIONS: CSF levels of NF-L, TAU, and GFAp appear to be elevated in CNS-LCH. It would be valuable if these markers were validated in order to serve as markers for early CNS-LCH, to monitor disease progression and to evaluate various treatment attempts for CNS-LCH.

Neuropsychological sequelae in patients with neurodegenerative Langerhans cell histiocytosis.

BACKGROUND: Patients with Langerhans cell histiocytosis (LCH) may develop neurodegeneration and significant CNS sequelae, affecting a significant proportion of the patients. We here aimed to investigate the neuropsychological consequences in more detail. METHODS: Using an extensive neuropsychological test battery, we evaluated nine LCH patients, 6-20 years old, with radiological signs indicative of neurodegeneration. RESULTS: Altogether 3/9 patients performed below 1 SD of normal for age on full IQ. Detailed analysis revealed that 4/9 had deficient performance IQ, whereas 1/9 had subnormal verbal IQ (defined as below 1 SD). Furthermore, 3/8 patients showed slow speed of performance for age. Notably, 8/9 (89%) had deficient verbal working memory and 7/8 (88%) performed below normal on visual-spatial working memory. CONCLUSIONS: The results indicate a specific, uneven neuropsychological profile in patients affected by CNS-LCH, with a decline particularly on perceptual tasks whereas the verbal performance was not as negatively influenced. Furthermore, verbal and visual-spatial working memory functions were below normal for age in all but one patient studied. LCH may easily be misdiagnosed, but it is important that individuals affected by CNS-LCH are diagnosed to provide advice and support. It remains a challenge to find a treatment reducing this unfortunate neurodegeneration.

Incidence of Langerhans cell histiocytosis in children: a population-based study.

BACKGROUND: Langerhans cell histiocytosis is a rare disease of unknown etiology. We wanted to assess the population-based incidence of LCH in a well-defined cohort of children. METHODS: We identified all children <15-years old treated with LCH during the 10 years period 1992-2001 at the Department of Pediatrics, Karolinska University Hospital in Stockholm, the referral center for children with LCH in Stockholm County. We also contacted the Departments of Dermatology, Orthopedics, and Neurosurgery for possible additional patients. RESULTS: Twenty-nine children (16 males) with LCH were identified, with a median age at diagnosis of 3.8 years (2 months-13.7 years). All children but one had a definitive diagnosis of LCH. The minimum incidence of LCH is estimated to 8.9/10(6) children per year. At diagnosis, 20 children (69%) had single system (SS) and 9 (31%) multisystem (MS) manifestations. Five of the 20 children with SS eventually developed MS disease, thus 14 (48%) had MS involvement at the maximal extent of disease (4.3/10(6) children per year). Interestingly, 22 children (76%) were diagnosed during the fall (September-November, n = 12) and winter (December-February, n = 10) seasons, as compared to seven children during the spring (March-May = 1) and summer (June-August = 6) seasons (P = 0.005, Chi-square). CONCLUSIONS: The incidence of childhood LCH in our study is higher than previously reported. In our patient cohort, LCH was more commonly diagnosed during the fall and winter season as compared to the spring and summer season. Whether this seasonal variation can be confirmed in larger studies and whether it has relevance for LCH pathophysiology remains to be elucidated.

Classification of metabolic and respiratory demands in fire fighting activity with extreme workloads.

Fire fighting work comprises work tasks requiring an energy yield at maximal or close to maximal levels of the individual. Due to the very nature of fire fighting more complex physiological variables are difficult to measure. We measured metabolic and respiratory responses in 15 male, professional fire fighters during simulated work tasks on a test ground. Work time was on the average 22 min with individual components of work tasks lasting 2-4 min. The mean oxygen consumption for the whole exercise (22 min) was 2.75+/-0.29 l/min. The most demanding work task demanded an oxygen uptake of 3.55+/-0.27 l/min. Corresponding values for respiratory minute volumes were 82+/-14 and 102+/-14l/min, respectively. Heart rates averaged 168+/-12 for the whole test and 179+/-13 beats/min for the heaviest work task. Two new classes for classification of intensive and exhausting, short term physical work are proposed for inclusion in ISO8996 and values for relevant parameters are proposed.

Effectiveness of a light-weight ice-vest for body cooling while wearing fire fighter's protective clothing in the heat.

The aim of the study was to examine the effects of wearing an ice-vest (ca 1 kg) on physiological and subjective responses in fire fighters. The experiments were carried out on a treadmill in a hot-dry environment. The physical cooling effect of the ice-vest was measured with a thermal manikin. The ice-vest effectively reduced skin temperatures under the vest. On average, heart rate was 10 beats/min lower, the amount of sweating was reduced by 13%, and subjective sensations of effort and warmth were lower during work with the ice-vest compared to work without it. Thermal manikin tests indicated that the useful energy available from the vest for body cooling was rather high (58%). In conclusion, the ice-vest reduces physiological and subjective strain responses during heavy work in the heat, and may promote efficient work time by 10%.