Quantifying atherogenic lipoproteins for lipid-lowering strategies: consensus-based recommendations from EAS and EFLM.

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDLC), LDL cholesterol (LDLC), and calculated non-HDLC (=total - HDLC) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDLC is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDLC shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a) [Lp(a)]-cholesterol is part of measured or calculated LDLC and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDLC declines poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDLC or apolipoprotein B (apoB), especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDLC includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apoB measurement can detect elevated LDL particle (LDLP) numbers often unidentified on the basis of LDLC alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.

How Well Do Laboratories Adhere to Recommended Clinical Guidelines for the Management of Myocardial Infarction: The CARdiac MArker Guidelines Uptake in Europe Study (CARMAGUE).

BACKGROUND: We undertook an assessment of current use of evidence-based guidelines for the use of cardiac biomarkers in Europe (EU) and North America (NA). METHODS: In 2013-2014 a web-based questionnaire was distributed via NA and EU biochemical societies. Questions covered cardiac biomarkers measured, analytical methods used, decision thresholds, and use of decision-making protocols. Results were collated using a central database and analyzed using comparative and descriptive nonparametric statistics. RESULTS: In EU, returns were obtained from 442 hospitals, 50% central or university hospitals, and 39% from local hospitals from 35 countries with 395/442 (89%) provided an acute service. In NA there were 91 responses (63.7% central or university hospitals, 19.8% community hospitals) with 76/91 (83.5%) providing an acute service. Cardiac troponin was the preferred cardiac biomarker in 99.5% (EU) and 98.7% (NA), and the first line marker in 97.7% (EU) and 97.4% (NA). There were important differences in the choice of decision limits and their derivations. The origin of the information was also significantly different, with EU vs NA as follows: package insert, 61.9% vs 40%; publications, 17.1% vs 15.0%; local clinical or analytical validation choice, 21.0% vs 45.0%; P = 0.0003. CONCLUSIONS: There are significant differences between EU and NA use of cardiac biomarkers. This probably relates to different availability of assays between EU and NA (such as high-sensitivity troponin assays) and different laboratory practices on assay introduction (greater local evaluation of assay performance occurred in NA).

Do laboratories follow heart failure recommendations and guidelines and did we improve? The CARdiac MArker Guideline Uptake in Europe (CARMAGUE).

BACKGROUND: Natriuretic peptides (NP) are well-established markers of heart failure (HF). During the past 5 years, analytical and clinical recommendations for measurement of these biomarkers have been published in guidelines. The aim of this follow-up survey was to investigate how well these guidelines for measurement of NP have been implemented in laboratory practice in Europe. METHODS: Member societies of the European Federation of Clinical Chemistry and Laboratory Medicine were invited in 2009 to participate in a web-based audit questionnaire. The questionnaire requested information on type of tests performed, decision limits for HF, turn-around time and frequency of testing. RESULTS: There was a moderate increase (12%) of laboratories measuring NP compared to the initial survey in 2006. The most frequently used HF decision limits for B-type NP (BNP) and N-terminal BNP (NT-proBNP) were, respectively, 100 ng/L and 125 ng/L, derived from the package inserts in 55%. Fifty laboratories used a second decision limit. Age or gender dependent decision limits were applied in 10% (8.5% in 2006). The vast majority of laboratories (80%) did not have any criteria regarding frequency of testing, compared to 33% in 2006. CONCLUSIONS: The implementation of NP measurement for HF management was a slow process between 2006 and 2009 at a time when guidelines had just been established. The decision limits were derived from package insert information and literature. There was great uncertainty concerning frequency of testing which may reflect the debate about the biological variability which was not published for most of the assays in 2009.

Update on current practice in laboratory medicine in respect of natriuretic peptide testing for heart failure diagnosis and management in Europe. The CARdiac MArker guideline Uptake in Europe (CARMAGUE) study.

BACKGROUND: The European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) initiated the CArdiac MARker Guidelines Uptake in Europe (CAMARGUE) Study to survey if current biomarker testing for heart failure (HF) in Europe is in accordance with up-dated guidelines. METHODS: A web-based questionnaire was distributed to clinical laboratories via European biochemical societies in 2019. Questions covered the type of natriuretic peptide (NP) assays performed, decision limits for HF, and opinion concerning requirement of different thresholds in patients with renal failure or obesity. RESULTS: There were 347 participating laboratories mostly from European countries with 266 offering NP testing. NP testing was increased from 67% to 77% between 2013 and 2019. NT-proBNP remained the preferred biomarker. Recommended decision limits were implemented for BNP (85%) and better focused for NT-proBNP (40%) than in the previous survey. The survey revealed that laboratorians are willing to support the translation of adjusted cut-off values for age, gender and for patients with conditions like renal insufficiency. CONCLUSION: Guidelines stimulate clinical laboratories to offer NP testing with high value for the diagnosis and management of HF, and to present adjusted medical decision limits. Future guidelines should encourage the use of personalized cut-offs for some confounding factors.

How well do laboratories adhere to recommended guidelines for dyslipidaemia management in Europe? The CArdiac MARker Guideline Uptake in Europe (CAMARGUE) study.

BACKGROUND: The CArdiac MARker Guidelines Uptake in Europe Study (CAMARGUE) initiated by the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) aims to survey the current use of evidence-based guidelines for dyslipidemia testing in Europe. METHODS: In 2019 a web-based questionnaire was distributed via EFLM National Societies to clinical laboratories in Europe. Questions covered pre-analytics, analytical methods, measurement units, flagging of decision thresholds, and use of decision-enhancing comments. RESULTS: Returns were obtained from 452 laboratories from 28 countries. Most laboratories always use nonfasting blood samples for lipid assays (66%). Lipid profiles are reported in mmol/L by 59% of the laboratories, mainly from 14 countries promoting the use of SI units. Important differences in flagging of decision thresholds were observed, with less than half of the laboratories applying the guideline-recommended LDL cholesterol threshold. Only 17% of the laboratories add an alert comment when familial hypercholesterolemia is suspected and 23% when risk of pancreatitis from hypertriglyceridemia is high. CONCLUSIONS: There are marked differences among laboratories in Europe in terms of pre-analytical, analytical, and post-analytical lipid management that could have an important clinical impact. This relates to different availability of assays or different laboratory practices on reporting and flagging of lipid profiles.

Quantifying atherogenic lipoproteins for lipid-lowering strategies: Consensus-based recommendations from EAS and EFLM.

The joint consensus panel of the European Atherosclerosis Society (EAS) and the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) recently addressed present and future challenges in the laboratory diagnostics of atherogenic lipoproteins. Total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, and calculated non-HDL cholesterol (=total - HDL cholesterol) constitute the primary lipid panel for estimating risk of atherosclerotic cardiovascular disease (ASCVD) and can be measured in the nonfasting state. LDL cholesterol is the primary target of lipid-lowering therapies. For on-treatment follow-up, LDL cholesterol shall be measured or calculated by the same method to attenuate errors in treatment decisions due to marked between-method variations. Lipoprotein(a)-cholesterol is part of measured or calculated LDL cholesterol and should be estimated at least once in all patients at risk of ASCVD, especially in those whose LDL cholesterol decline poorly upon statin treatment. Residual risk of ASCVD even under optimal LDL-lowering treatment should be also assessed by non-HDL cholesterol or apolipoprotein B, especially in patients with mild-to-moderate hypertriglyceridemia (2-10 mmol/L). Non-HDL cholesterol includes the assessment of remnant lipoprotein cholesterol and shall be reported in all standard lipid panels. Additional apolipoprotein B measurement can detect elevated LDL particle numbers often unidentified on the basis of LDL cholesterol alone. Reference intervals of lipids, lipoproteins, and apolipoproteins are reported for European men and women aged 20-100 years. However, laboratories shall flag abnormal lipid values with reference to therapeutic decision thresholds.

Association of angiotensin-converting enzyme insertion-deletion polymorphism with preeclampsia.

The aim of this study was to determine if insertion-deletion polymorphism of angiotensin-converting enzyme is a risk factor for the development of preeclampsia. Sixty women with preeclampsia and 50 normotensive pregnant women were included in this study. Preeclampsia was defined as blood pressure >140/90 mmHg in a previously normotensive women with proteinuria >300 mg/L in a 24-hours. Twelve women also had preeclampsia in previous pregnancy. The genotyping of polymorphism in the intron 16 of the angiotensin-converting enzyme was performed by the polymerase chain reaction followed by the agarose electrophoresis. The patients were divided into three groups according to the presence (I) or absence (D) of insertional polymorphism (II, ID, and DD). Genotype distribution and allele frequencies were compared by Mantel-Haenszel chi2 testing. The frequency of DD genotype was not significantly higher in women with preeclampsia (26/60) than in the control group (14/50, p=0.096). The D allele frequency was significantly higher in 17 women with preeclampsias who required delivery before 34 weeks of pregnancy (0.735), than in 43 women in whom obstetric complications took place after 34 weeks of pregnancy (0.56, p=0.036). The D allele frequency was 0.83 in women having recurrent preeclampsia, i.e. significantly higher compared with women, who were for the first time, experienced preeclampsia (0.57, p=0.013). This study showed a significantly positive association between D allele frequency and risk of recurrent preeclampsia and preterm delivery before 34 weeks of pregnancy. The deletion genotype could be an important contributing factor for an early onset and recurrent preeclampsia.

[Influence of gene polymorphisms in adhesion molecules and inflammation mediators as risk factors for coronary heart disease and myocardial infarction--an overview]. / Utjecaj polimorfizama gena za adhezijske molekule i medijatore upale kao cimbenika rizika za koronarnu bolest srca i infarkt miokarda.

Cardiovascular diseases are influenced by inheritance and environmental factors. There is a growing number of genetic variants, which may be included in the genesis and development of coronary artery disease (CAD). CAD or ischemic heart disease is a set of clinical symptoms caused by inadequate transport of oxygen because of changes in coronary circulation leading to myocardial ischemia. The most common cause of CAD is atherosclerosis of coronary arteries, which primarily narrows or occludes the lumen of coronary arteries or stimulates thrombosis. In this review, the role of the most important polymorphisms in adhesion molecules, intracellular adhesion molecule-1, integrins alpha2beta1 and beta3, E-selectin as well as of inflammation mediators, tumor necrosis factors alpha and beta, in the development of CAD risk and myocardial infarction is discussed. A review of different genotyping results provides an insight into the mechanisms responsible for the disease risk and helps detect the key sets of predictive markers that are clinically informative.

[Quality in health care]. / Kvaliteta zdravstvene skrbi.

Quality in health care is the basic requirement in each medical intervention based on good medical praxis and principles of medicine based on scientific evidence. However, health systems and medical personnel in health insitutions in Europe as well as other parts of the world are nowadays confronted with public requirements for better care and more quality in health system, less risks and undesirable outcomes of medical interventions. Based on recent results of investigations on sources for mistakes it was persumed that it might be the consequence of more complex technologies used in diagnosis and treatment, as well as shortage of time between new development and application in medical practice, the lack of information technologies needed for follow up of interventions, ageing of population and more chronicaly ill patients etc. Therefore, systematic approach in implementation of quality improvement programs is first priority for any health system which is oriented to patients needs and satisfaction. In this rewiev article the basic terms and methods used for quality improvement in health care is presented, including quality assessment, quality control and management of quality.

[Lipoprotein lipase--physiological and pathophysiological roles of this gene variant in Croatian population]. / Lipoprotein lipaza--fizioloske i patofizioloske uloge te genske varijante u Hrvatskoj populaciji.

Lipoprotein lipase is a key enzyme in hydrolysis of triglyceride and exchange of lipids between lipoproteins in circulation. It has also been found for lipoprotein lipase to play key roles in number of pathophysiological conditions. Over hundred different lipoprotein lipase gene variants have been described in the literature. Lipoprotein lipase gene has been observed as a key factor involved in the pathogenesis of hypertriglyceridemia, coronary heart disease and pancreatitis. In Croatian population the following gene variants have been described: -93T/G, D9N, V108V, N291S, S447X, Pvu II i Hind III. The most important finding was the first mutation W86R which caused familial hypertriglyceridemia. The investigation of mutations and polymorphisms may open the new directions for molecular diagnostics of hypertriglyceridemia and help us recognize the new mutations. Differential diagnosis of hypertriglyceridemia and medical practice involved in their prevention and treatment may be improved by knowing the frequency of lipoprotein lipase gene variants as well as their influence on lipid profile.

Are Heart Failure Management Recommendations and Guidelines Followed in Laboratory Medicine in Europe and North America? The Cardiac Marker Guideline Uptake in Europe (CARMAGUE) Study.

BACKGROUND: The aim of this survey was to investigate how well heart failure (HF) guidelines for use of natriuretic peptides (NPs) have been implemented in laboratory practice in Europe and North America. METHODS: In 2013 and 2014, a web-based questionnaire was distributed via North American and European biochemical societies. Questions covered assay performed, reason for method choice, decision limits for HF, and laboratory accreditation status. RESULTS: There were 442 European Union and 91 North American participating laboratories with response rates of 50% and 64% from major or university hospitals, respectively. NP measurements were offered in 67% of European Union and 58% of North American respondents. N-terminal pro-B-type natriuretic peptide (NT-proBNP) was most widely used in Europe (68%) and B-type natriuretic peptide (BNP) was more commonly used (58%) in North America. The most frequent reason for use of a specific assay was the availability of instruments that measure either NT-proBNP (51%) or BNP (67%). For diagnosis of acute HF, NT-proBNP decision limits were diverse; age-dependent limits based on the 2012 European Society of Cardiology (ESC) recommendations were used in only 17% of European sites and 26% of North American sites. For BNP, the guideline-recommended acute HF decision limit of 100 ng/L was better adhered to in Europe (48%) and North America (57%). Surprisingly, similar decision limits were stated for acute and chronic HF by >50% of respondents. CONCLUSIONS: NP measurement for HF diagnosis was available in >50% of responding laboratories. However, guideline recommended cutoff values for both acute and chronic HF were still implemented in <30% of participating medical centers.

Association of two genetic variations of lipoprotein lipase, S447X and Hind III, with coronary artery disease and hypertriglyceridemia.

This study was performed to assess the effect of the S447X and Hind III lipoprotein lipase gene polymorphisms on development of coronary artery disease and hypertriglyceridemia. The study included 132 patients and 98 healthy control subjects of Croatian descent. The lipoprotein lipase S447X polymorphism was associated with coronary artery disease and hypertriglyceridemia, as indicated by the lower frequency of S447 allele in the patient group (p = 0.005) and odds ratio (O.R = 0.40, p = 0.006). The patient and control groups also showed a significant difference in the distribution of Hind III/S447X genotype combinations (p = 0.013). There were no significant associations with lipid parameters for any genotype or genotype combination in the patient group. Frequencies of the S447X polymorphism and S447X/Hind III combinations differed between the CAD/TG and control group, thus these polymorphisms may be associated with CAD and hypertriglyceridemia.

[The frequencies of apolipoprotein E genotypes in health and disease in the Croatian population--an overview of expectations and real results]. / Ucestalost genotipova apolipoproteina e u zdravlju i bolesti: ocekivanja i rezultati u hrvatskih ispitanika.

The aim of the overview is to show the distribution of common apolipoprotein E (APOE) genotypes in the Croatian population, and to test whether it could serve as a new molecular biomarker in some clinical entities. The study included the following groups: patients with angiographically confirmed coronary artery disease, myocardial infarction, Alzheimer's dementia, vascular dementia, hyperlipidemias, diabetes mellitus, pancreatitis, and healthy subjects. Group comparisons of different clinical entities and control group were performed using Pearson's Chi2-test. There was no difference in APOE genotype frequencies between coronary artery disease neither myocardial infarction and control group. The ApoE genotype frequencies in patients with Alzheimer's disease were significantly different from those in the control group. APOE-4 allele tends to be a risk factor for the development of Alzheimer's disease. The frequencies were only marginally different in vascular dementia. Patients with hypercholesterolemia, those with inherited familial hypercholesterolemia, children with diabetes mellitus, and patients with pancreatitis of different etiology showed distributions of APOE genotypes that differed from the control group. It is concluded that the frequencies of APOE genotypes yielded no statistically significant result to confirm the association between APOE genotypes and any specific disease with the exception of Alzheimer's disease; APO-epsilon4 allell has become one of the important biomarkers in diagnosis of Alzheimer's dementia.

Proinflammatory factors in saliva as possible markers for periodontal disease.

Studies have indicated that host inflammatory proteins, enzymes and indicators of bone metabolism present in saliva differ in different types of periodontal disease. However, the number of markers analyzed was limited and the effect of edentulousness was not examined. We measured the concentration of host inflammatory proteins: C-reactive protein (CRP), C3 and C4 complement components, alpha-2-macroglobulin (alpha-2M) and tumor-necrosis factor (TNF) in unstimulated saliva of 14 periodontally healthy (PH), 9 edentulous persons (EP), 10 patients with chronic periodontitis (CP) and 18 with aggressive periodontitis (AgP). TNF was below the level of detection in all samples except one. Edentulous persons and patients with CP had significantly reduced concentrations of CRP, C3 and alpha-2M. Edentulous persons and AgP patients had lower C4 concentrations. We can conclude that edentulous persons and CP patients have reduced salivary concentrations of host inflammatory proteins. These findings suggest that a reduction in host responsiveness might play a role in the pathogenesis of CP.

[Markers of periodontal destruction in saliva of periodontitis patients]. / Biljezi parodontne destrukcije u slini pri parodontitisu.

UNLABELLED: Periodontal diseases result from interactions between periodontal microflora and the multifaceted response of the host. Markers of this interrelationship can be found in gingival crevicular fluid and saliva samples indicating early periodontal disease activity. Studies of host defense mediators in saliva of patients with periodontal diseases are very scarce. AIM: The goal of this study was therefore to investigate interrelationships between mediators of local immunity in host saliva and clinical parameters of periodontal destruction in persons with chronic and aggressive periodontitis. METHODS AND SUBJECTS: Host defense indicators were measured using enzyme-immunochemistry tests in unstimulated saliva samples of persons with periodontitis. The degree of periodontal destruction was determined by measuring attachment loss. Subjects were divided into two groups: persons with mild signs of chronic periodontitis and persons with severe signs of aggressive periodontitis. Hypotheses about the structure of those samples and their interrelationship were tested using non-parametric methods. RESULTS: Results indicated that C-reactive protein, C3 component of the complement, alfa 2-macroglobulin and interleukin-6 levels differ significantly between patients with chronic and aggressive periodontitis. Interleukin-6, influencing cells with osteoblastic phenotype, is present at a high level in patients with aggressive periodontitis. Calcium was much lower than in healthy persons. Trypsin levels were lower in patients with periodontitis than in healthy persons. We found a significant interrelationship between host response mediators as measured in saliva and periodontal destruction measured by clinical attachment loss. CONCLUSION: The levels of host defense mediators in saliva are different for chronic and aggressive periodontitis. This findings might help in estimating the course and progression of periodontal destruction, thus providing clinical benefits in treatment planning.

[Development of laboratory information system--quality standards]. / Razvoj laboratorijskog informacijskog sustava--norme kvalitete.

The aim of the study was to determine structural modules of laboratory information system (LIS) for the application of new biomedical and information technologies by utilizing current organizational trends. The method used included definition of structural modules according to significant LIS properties, e.g., a large number of data, automation of analyses and rapid exchange of information, and according to the process of information establishment the collection, organization, selection, synthesis and distribution. Thus, outdated distributed software at the Clinical Institute of Laboratory Diagnosis has now been replaced by modular organization. Modules have been developed for the following: data input, online operation of laboratory instruments, preparation of results, compilation of medical documentation on quality assurance based on the application of quality standards, management of finances, and for point of care testing. The method of re-engineering as well as adherence to EN and ISO quality standards were utilized in planning the development of LIS based on the application of new information technologies and in shaping business processes. The application of re-engineering in LIS development results in quality improvement, reduces the cost and time necessary for performance of procedures, and improves relations in organizational structure.

Missense mutation W86R in exon 3 of the lipoprotein lipase gene in a boy with chylomicronemia.

BACKGROUND: Familial LPL deficiency is a rare inborn error of metabolism caused by mutational change within the LPL gene, which leads to massive hypertriglyceridemia. METHODS: The underlying molecular defect in a boy of Croatian descent was studied by SSCP analysis, DNA sequencing and finally confirmed by RFLP. RESULTS: DNA analysis showed the child to be a homozygote and his parents heterozygotes for TGG-->CGG change in codon 86 of the LPL gene, which leads to W86R amino acid substitution. DNA sequence analysis also showed a silent mutation in the third exon of father's DNA, V108V. Determination of some LPL gene polymorphisms showed the child and his parents to have HindIII/H+H+ and both S447 wild-type alleles, whereas for PvuII the parents had P(+)P- and the child P(+)P+ genotype. CONCLUSIONS: In this case, W86R mutation was the reason for the production of nonfunctional enzyme and consequently triacylglycerol (TG) exceeding 15 mmol/l. This implies the risk of frequent episodes of acute pancreatitis. Decreased LPL activity leads to elevated triacylglycerol levels and reduced HDL-cholesterol, both risk factors for the development of coronary artery disease. LPL genotyping especially of young patients with hypertriglyceridemia is therefore necessary and justifiable.

ApoE genotyping and response to galanthamine in Alzheimer's disease--a real life retrospective study.

This study was undertaken to evaluate the effect of galanthamine, a new cholinesterase inhibitor on cognitive performances in 84 patients with various apoE genotype and Alzheimer's disease (AD) during the six-month treatment. The diagnosis of AD was made on the basis of NINCDS/ADRDN criteria. ApoE4 genotype was determined by PCR procedure. The cognitive performance was assessed MMSE at baseline and six months later. The difference among the groups was statistically analyzed by ANOVA model and Pearson's chi2-test. The MMSE at baseline in all completes was 18.0 +/- 3.73, whereas the mean value of MMSE after 6 months was 16.4 +/- 5.61 indicating significant deterioration (p < 0.01). Of the 84 patients, 14 (169%) were apoE4 homozygous, 41 (49%) were heterozygous, whereas 29 (35%) were apoE4 negative. The significant number of responders was observed among apoE4 homozygous patients (71%; chi2 = 6.89; p = 0.032). The subgroup of apoE4 homozygous patients with AD in its mild to moderate stage may be considered as responders to galanthamine.

[Gaucher disease: diagnosis and treatment]. / Gaucherova bolest: dijagnostika i mogucnosti lijecenja.

Gaucher's disease is the most common lysosomal storage disorder. It was identified in 1882 by Phillipe Gaucher, a French dermatologist. However, it was not until 1965 that Gaucher disease was found to be due to a deficiency in the enzyme glucocerebrosidase (EC 3.2.1.45) which breaks down glucocerebroside, a cell membrane component. The deficiency in this enzyme leads to an accumulation of glucocerebroside within the lysosomes of macrophages throughout the body. Gaucher's disease is classified into three types: type 1 (non-neuronopathic), type 2 (acute neuronopathic), and type 3 (subacute neuronopathic). Of the three, type 1 is the most common, affecting one in 40,000-200,000 people and having a high prevalence among Ashkenazi Jews, affecting one in 450-1500. The signs and symptoms of type 1 disease demonstrate marked heterogeneity, from asymptomatic or mildly symptomatic, to severe disability with disfigurement and even death. Hepatosplenomegaly and thrombocytopenia are well documented. Less well-recognized are often insidious skeletal complications which affect the majority of type 1 patients and which are its most debilitating feature. In addition to clinical suspicion, some morphologic, hematologic and biochemical indicators can help establish the diagnosis. However, definitive diagnosis is only made by determining the catalytic activity of the lysosomal enzyme glucocerebrosidase. Confirmation of heterozygosity requires the use of molecular biotechnology methods. About 150 mutations of the glucocerebrosidase gene have been identified in patients with Gaucher's disease, some of which are predictive of phenotype. The history of treatment of Gaucher disease started with splenectomy and continued with bone marrow transplantation, before the recent introduction of safe and effective enzyme replacement therapy. In Croatia, nine patients with type 1 Gaucher's disease have been identified so far. Seven patients are on enzyme replacement therapy, and past results demonstrated significant improvement in all clinical symptoms, without development of any side effects. However, new treatments, such as substrate balance therapy and gene therapy, may become available within the next few years. The place, if any, that such therapies will have in the treatment of patients with Gaucher's disease will be dependent on the results of clinical studies currently in progress.