BACKGROUND: The aim of our study was to investigate serum chitotriosidase level in tuberculosis patients, its relationship with microbiological and clinical parameters, and response to treatment.
METHODS: This longitudinal panel study included 149 patients with confirmed TB disease. Serum chitotriosidase activity was measured at the beginning and the end of treatment. Factors associated with chitotriosidase activity were explored using univariate and multivariable logistic regression analysis.
RESULTS: Out of 149 study participants, 71(47.7%) were female. The mean age was 53.0 (SD = 18.2). Majority of cases were new 118(79.2), predominantly 145 (97.3%) having pulmonary tuberculosis. More than half of the patients were sputum smear positive 91 (61.1%) while culture positive in 146 (98%) of them. According to radiological findings, cavitary lesions were found in 92 (63.4%) patients. Anti TB treatment was associated with significant decrease in serum chitotriosidase level (< 0.001). New TB treatment (OR = 4.41%;95% CI = 1.20-9.89), and cavitary lesions (OR = 3.86;95%CI = 0,59-26.57) were found to be significantly associated with decrease of chitotriosidase activity.
CONCLUSIONS: The results of our study showed that serum chitotriosidase values are strong biomarkers for starting anti TB treatment and for treatment monitoring, since decrease in serum chitotriosidase level can predict favorable treatment response in patients with tuberculosis. Further studies are needed to explore these, and other factors associated with chitotriosidase activity among tuberculosis patients.

Sarcoidosis is a granulomatous disease of unknown etiology that can affect almost any organ. Although the acute form can have spontaneous regression, a certain number of patients can have a chronic form, which leads to an increase in mortality and a decrease in the quality of life. Considering that the risk factors are still unknown, we wanted to compare the characteristics of patients with acute and chronic forms of sarcoidosis in Serbia in order to determine significant differences between them with hopes of contributing to everyday clinical practice. A total of 2380 patients treated in our clinic were enrolled in this study. They were separated into the following two groups: 1126 patients with acute form and 1254 patients with chronic form. They were further compared by gender, smoking status, radiological status, exposition, biomarkers for sarcoidosis, organ involvement, and other comorbidities; the distribution of patients according to regions of Serbia was also noted. Statistical significance was found in radiological findings (p < 0.001), biomarkers (calcium in 24 h urine p < 0.001; chitotriosidase p = 0.001), and the affliction of organs (p < 0.001). The differences noted in this paper could help improve our understanding of this disease.

Gaucher disease (GD) is a lysosomal storage disorder with glucocerebroside accumulation in the macrophages. The disease is divided into three types based on neurocognitive involvement with GD1 having no involvement while the acute (GD2) and chronic (GD3) are neuronopathic. The non-neurological symptoms of GD3 are well treated with enzyme replacement therapy (ERT) which has replaced hematopoietic stem cell transplantation (HSCT). ERT is unable to prevent neurological progression as the enzyme cannot cross the blood-brain barrier. In this retrospective study, we report the general, neurocognitive, and biochemical outcomes of three siblings with GD3 after treatment with ERT or HSCT. Two were treated with HSCT (named HSCT1 and HSCT2) and one with ERT (ERT1). All patients were homozygous for the c.1448 T > C, (p.Leu483Pro) variant in the GBA1 gene associated with GD3. ERT1 experienced neurocognitive progression with development of seizures, oculomotor apraxia, perceptive hearing loss and mental retardation. HSCT1 had no neurological manifestations, while HSCT2 developed perceptive hearing loss and low IQ. Chitotriosidase concentrations were normal in plasma and cerebrospinal fluid (CSF) for HSCT1 and HSCT2, but both were markedly elevated in ERT1. We report a better neurological outcome and a normalization of chitotriosidase in the two siblings treated with HSCT compared to the ERT-treated sibling. With the advancements in HSCT over the past 25 years, we may reconsider using HSCT in GD3 to achieve a better neurological outcome and limit disease progression.

Leukodystrophies represent a large and complex group of inherited disorders affecting the white matter of the central nervous system. Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a rare leukodystrophy which still needs the proper identification of diagnostic, prognostic, and monitoring biomarkers. The aim of this study was to determine the diagnostic and prognostic value of chitinases and neurofilament light chain as biomarkers for ALSP. A cross-sectional study was performed to analyze cerebrospinal fluid levels of chitinases (chitotriosidase and chitinase 3-like 2) and neurofilament light chain in five different groups: (i) normal health individuals; (ii) patients with definitive diagnosis of ALSP and genetic confirmation; (iii) asymptomatic patients with CSF1R variants; (iv) patients with other adult-onset leukodystrophies; and (v) patients with amyotrophic lateral sclerosis (external control group). Chitinase levels showed a statistical correlation with clinical assessment parameters in ALSP patients. Chitinase levels were also distinct between ALSP and the other leukodystrophies. Significant differences were noted in the levels of chitinases and neurofilament light chain comparing symptomatic (ALSP) and asymptomatic individuals with CSF1R variants. This study is the first to establish chitinases as a potential biomarker for ALSP and confirms neurofilament light chain as a good biomarker for primary microgliopathies.

BACKGROUND: Cystine-depleting therapy in nephropathic cystinosis is currently monitored via the white blood cell cystine assay, although its application and usefulness are limited by practical and technical issues. Therefore, alternative biomarkers that are widely available, more economical and less technically demanding, while reliably reflecting long-term adherence to cysteamine treatment, are desirable. Recently, we proposed chitotriosidase enzyme activity as a potential novel biomarker for the therapeutic monitoring of cysteamine treatment in cystinosis. In this study, we aimed to validate our previous findings and to confirm the value of chitotriosidase in the management of cystinosis therapy.
METHODS: A retrospective study was conducted on 12 patients treated at the National Institutes of Health Clinical Center and followed up for at least 2 years. Plasma chitotriosidase enzyme activity was correlated with corresponding clinical and biochemical data.
RESULTS: Plasma chitotriosidase enzyme activity significantly correlated with WBC cystine levels, cysteamine total daily dosage and a Composite compliance score. Moreover, plasma chitotriosidase was a significant independent predictor for WBC cystine levels, and cut-off values were established in both non-kidney transplanted and kidney transplanted cystinosis patients to distinguish patients with a good versus poor compliance with cysteamine treatment. Our observations are consistent with those of our previous study and validate our findings.
CONCLUSIONS: Chitotriosidase enzyme activity is a valid potential alternative biomarker for monitoring cysteamine treatment in nephropathic cystinosis patients.
CONCLUSIONS: Chitotriosidase enzyme activity is a valid potential alternative biomarker for monitoring cysteamine treatment in nephropathic cystinosis patients.

OBJECTIVE: To assess the relationship between plasma chitotiosidase (CHIT) level and mortality in hospitalized patients with COVID-19.
METHODS: 347 hospitalized patients with COVID-19 were enrolled in our single-center cohort prospective observational study. On the first day of hospitalization the patients were assessed by the level of CHIT in the venosus blood to addition to default laboratory examinations. The primary endpoint was all-cause death. The survival after hospital discharge were assessed via phone calls on 90 and 180 days since inclusion to the study (NCT04752085).
RESULTS: Our study included 347 patients. The first symptoms appeared in 7 days [5; 7] before hospitalization; 283 (84.3%) patients had less than 50% of the involvement of the lung tissue to the inflammation process (CT 0-2); 36 (10.4%) patients had died since the start of our investigation; 30 (83.3%) of them died during hospitalization, others -no later than 60 days; 68 (19%) people didn\'t answer during phone call. The survivor\'s activity of the enzyme in the deceased was significantly lower in compare to deceased patients (90.5 [40.2; 178.0] nmol/h/mL vs 180.0 [77.2; 393.2] nmol/h/mL; p=0.001). Survivor of the patients with a higher level of the activity of the CHIT (more than 171 nmol/h/mL) was statically significantly lower.
CONCLUSIONS: Rising of the CHIT\'s activity more than 171 nmol/h/mL might be an early independent predictor of the bad prognosis of the patients, who were hospitalized with COVID-19 infection.
Цель. Оценить связь между активностью хитотриозидазы (ХТЗ) плазмы крови и летальностью от новой коронавирусной инфекции. Материалы и методы. В проспективном когортном наблюдательном одноцентровом исследовании приняли участие 347 человек, госпитализированных с диагнозом новой коронавирусной инфекции, вызванной SARS-CoV-2. В дополнение к стандартному обследованию в день госпитализации этим пациентам определялась активность ХТЗ в периферической крови. Первичной конечной точкой являлась смерть от любых причин. Выживаемость после выписки из стационара оценивалась с помощью телефонного интервью на 90 и 180-й день от момента включения в исследование (NCT04752085). Результаты. В исследование включены 347 пациентов. Срок от появления первых симптомов до госпитализации составил 7 [5; 7] дней. На момент включения в исследование у 283 (84,3%) пациентов объем поражения легочной ткани составлял менее 50% (0–2 степень по компьютерной томографии). За период наблюдения умерли 36 (10,4%) пациентов, 30 (83,3%) из них скончались в первые 30 дней наблюдения, остальные – не позже 60-го дня; 68 (19%) человек не ответили на телефонные звонки. Активность ХТЗ на момент госпитализации у выживших больных оказалась достоверно ниже по сравнению с умершими (90,5 [40,2; 178,0] нмоль/ч/мл vs 180,0 [77,2; 393,2] нмоль/ч/мл; p=0,001). Выживаемость пациентов с изначально повышенной (более 171 нмоль/ч/мл) активностью ХТЗ оказалась достоверно хуже. Заключение. Повышение активности ХТЗ более 171 нмоль/ч/мл может служить ранним предиктором неблагоприятного исхода у пациентов, госпитализированных по поводу новой коронавирусной инфекции.

Chitotriosidase (CHIT), a mammalian chitinase secreted by neutrophils and activated macrophages, is increased in both cardiovascular disease (CVD) and type 2 diabetes (T2D). Arterial stiffness rises early in T2D and increases the risk of CVD. The aim of this study is to evaluate CHIT activity as an early biomarker of arterial stiffness in people with T2D free from overt vascular complications. In this cross-sectional study, arterial stiffness as measured using standard pulse wave velocity (PWV) was evaluated in 174 people with T2D without overt vascular disease. Then, we measured CHIT serum activity with an electrochemiluminescence assay in two subgroups of participants: 35 with the highest (high-PWV) and 40 with the lowest (low-PWV) PWV values. CHIT activity was no different between the low-PVW and high-PWV groups (12.7 [9.6-17.9] vs. 11.4 [8.8-15.0] nmol/mL/h, respectively). Compared with the low-PWV group, the high-PWV participants were older (p < 0.001); had a longer duration of diabetes (p = 0.03); higher ankle-brachial index ABI (p = 0.04), systolic blood pressure (p = 0.002), diastolic blood pressure (p = 0.005), fasting blood glucose (p = 0.008), and HbA1c (p = 0.005); and lower eGFR (p = 0.03) and body mass index (BMI) (p = 0.01). No association was present with sex, duration of diabetes, age, BMI, peripheral blood pressure, laboratory parameters, and glucose-lowering medications or ongoing antihypertensive therapy. Although no association was found, this study provides novel data about the association of CHIT activity with CVD, focusing on a specific outcome (arterial stiffness) in a well-defined population of subjects with T2D without established CVD.

A personalized treatment decision for Gaucher disease (GD) patients should be based on relevant markers that are specific to GD, play a direct role in GD pathophysiology, exhibit low genetic variation, reflect the therapy, and can be used for all patients. Thirty-four GD patients treated with enzyme replacement therapy (ERT) or substrate reduction therapy (SRT) were analyzed for platelet count, chitotriosidase, and tartrate-resistant acid phosphatase activity in plasma samples, and quantitative measurement of Lyso-Gb1 was performed in dried blood spots. In our ERT and SRT study cohorts, plasma lyso-GL1 correlated significantly with chito-triosidase (ERT: r = 0.55, p < 0.001; SRT: r = 0.83, p < 0.001) and TRAP (ERT: r = 0.34, p < 0.001; SRT: r = 0.88, p < 0.001), irrespective of treatment method. A platelet count increase was associated with a Lyso-Gb1 decrease in both treatment groups (ERT: p = 0.021; SRT: p = 0.028). The association of Lyso-Gb1 with evaluated markers was stronger in the SRT cohort. Our results indicate that ERT and SRT in combination or in a switch manner could offer the potential of individual drug effectiveness for particular GD symptoms. Combination of the key biomarker of GD, Lyso-Gb1, with other biomarkers can offer improved response assessment to long-term therapy.

The therapy and management of Gaucher disease (GD) have radically changed with the use of substrate reduction therapy, of which eliglustat is the most widely known drug, allowing it to overcome the limits of enzyme replacement therapy (ERT). The rarity of GD and the limited use of eliglustat outside clinical trials require further study of its strengths and weaknesses.
In this study, we evaluated the effectiveness and safety of eliglustat in a cohort of 12 patients with GD followed up in our center, reporting a reduction in both chitotriosidase (394.3 vs 181.1 nmol/h/mL, P = 0.027) and glucosylsphingosine values (45.1 vs 18.9 ng/mL, P <0.001) after at least 12 months of therapy compared with baseline, regardless of patient demographic characteristics and GD characteristics.
There were no drug-related serious adverse effects and no drug-related cardiac events. Most adverse events were mild and transient, mainly dyspepsia and abdominal pain. Of interest, we reported an absence of statistical difference in terms of response regarding glucosylsphingosine reduction in relation to naive or prior exposure to ERT (P = 0.296), which was confirmed also when patients were placed in naive and treated groups for <5 vs >5 years (P = 0.667).
The use of eliglustat immediately after diagnosis may guarantee the best treatment for patients with milder phenotypes or with aggressive disease after an initial stabilization with ERT compared with ERT, which cannot adequately remove the disease burden despite the apparent response, thus potentially reducing future complications caused by substrate deposits.

Several reports have pointed out that Chitinases are expressed and secreted by various cell types of central nervous system (CNS), including activated microglia and astrocytes. These cells play a key role in neuroinflammation and in the pathogenesis of many neurodegenerative disorders. Increased levels of Chitinases, in particular Chitotriosidase (CHIT-1) and chitinase-3-like protein 1 (CHI3L1), have been found increased in several neurodegenerative disorders. Although having important biological roles in inflammation, to date, the molecular mechanisms of Chitinase involvement in the pathogenesis of neurodegenerative disorders is not well-elucidated. Several studies showed that some Chitinases could be assumed as markers for diagnosis, prognosis, activity, and severity of a disease and therefore can be helpful in the choice of treatment. However, some studies showed controversial results. This review will discuss the potential of Chitinases in the pathogenesis of some neurodegenerative disorders, such as Alzheimer\'s disease, Parkinson\'s disease, amyotrophic lateral sclerosis, and multiple sclerosis, to understand their role as distinctive biomarkers of neuronal cell activity during neuroinflammatory processes. Knowledge of the role of Chitinases in neuronal cell activation could allow for the development of new methodologies for downregulating neuroinflammation and consequently for diminishing negative neurological disease outcomes.