Preporuke za primenu i odredivanje tumorskih markera kod neoplazmi neuroendokrinog sistema

Neuroendocrine tumors derive from neuroendocrine cells, which upon specific stimulation secrete stimulation secrete hormones regulating various bodily functions. We will discuss the group of neuroendocrine tumors which is consisted of: carcinoids, endocrine pancreatic tumors, neuroblastomas medullary thyroid carcinomas and pheochromocytomas. The tumors which derived from endocrine glads will be discused, as well as, we will pay attention on tumors which derived from so called "diffuse" neuroendocrine cell system of the gastrointestinal tract. In fact, this is the largest endocrine organ of the body. About 50 different neuroendocrine cell types of the gastrointestinal tract have been indentified. One of the currently recomended diagnostic approach to these lesions is the determination of characteristic bioactive amines and peptides of neuroendocrine activity, which is changed in neoplasms. The wide spectrum of clinical symptoms are associated with lesions of endocrine glands, and dispersed neuroendocrine system, results from their collective ability to secrete an extensive array of peptide hormones and bioactive amines, that differe according to the tumor type. The main aim of this disscusion is evaluation of these potential tumor markers, and proposing using some of those markers in our conditions.Neuroendokrini tumori vode poreklo iz neuroendokrinih ćelija, koji pod uslovima specifične stimulacije sekretuju hormone, regulišući niz različitih funkcija u organizmu. U radu je opisana grupa neuroendokrinih tumora koja se sastoji od: karcinoida endokrinih tumora pankreasa, neuroblastoma, medularnog karcinoma tiroidee i feohromocitoma. Biće diskutovani tumori koji potiču iz endokrinih žlezda, kao i oni koji vode poreklo iz takozvanog "difuznog" neuroendokrinog ćelijskog sistema gastrointestinalnog trakta. Radi se o najvećem endokrinom organu u organizmu. Oko 50 različitih neuroendokrinih ćelijskih tipova gastrointestinalnog trakta je indentifikovano. Važan dijagnostički segment u tretmanu ovih tumora, je određivanje biogenih amina i peptida, čija je aktivnost izmenjena kod pojave neoplazmi. Širok je spektar kliničkih simptoma kod pojave ove vrste tumora, a svi su posledica sposobnosti tumora da sekretuju povećane količine peptinih hormona i biogenih amina. Glavni ciljevi ovog teksta su procena važnosti ove grupe tumorskih markera, kao i predlozi za njihovo korišćenje u našim uslovima

Antifosfolipidna antitela u zdravih srpskih osoba srednjih godina - preliminarni podaci

Background: The investigation of the prevalence of the IgG and the IgM isotypes of anticardiolipin (aCL) and antib2glycoprotein I (ab2gpI) Abs in healthy Serbian middle-aged subjects was the main goal of our study. In addition, we analyzed the potential associations of above-mentioned Abs with serum proteins and lipids/lipoproteins. Methods: Forty healthy subjects were included in our study. Obesity (BMI 30 kg/m2) was present in 8/40 (20%) subjects. Titers of analyzed Abs were measured by ELISA. Results: The prevalence of IgG and IgM ab2gpI Abs was 5% and 12.5%, respectively, while the prevalence of IgM aCL was 10%. The IgG ab2gpI Abs were significantly different between subjects with normal triglycerides levels and those with hypertriglyceridemia (Mann-Whitney, P = 0.014). The significant difference in hsCRP concentrations was observed between subjects with the increased levels of the IgM isotype of aCL Abs and those with normal IgM aCL values (Mann-Whitney, P = 0.028). Conclusions: Dyslipidemia and BMI ≥30 were associated with aPL Abs and therefore, the correction of BMI and lipid status might be beneficial in reduction or elimination of predisposing factors that might trigger thrombotic events in otherwise healthy middle-aged subjects. Larger national study is necessary to confirm our findings.Uvod: Analiza prevalentnosti IgG i IgM izotipa antikardiolip- inskih (aCL) i anti- b2glikoprotein I (ab2gpI) At kod zdravih sredove~nih stanovnika Srbije je bila glavni cilj na{e studije. Dodatno, analizirali smo potencijalnu povezanost gore- navedenih At sa serumskim proteinima i lipidima/lipopro- teinima. Metode: 40 zdravih ispitanika je bilo uklju~eno u na{u studiju. Gojaznost (BMI ≥ 30 kg/m2) je uo~ena kod 8/40 (20%) osoba. Titri analiziranih antitela su utvr|ivani ELISA testom. Rezultati: Prevalentnost IgG i IgM ab2gpIAt je bila 5% i 12.5%, redom, dok je prevalentnost IgM aCL bila 10%. Nivoi IgG ab2gpI At su se zna~ajno razlikovali izme|u ispi- tanika sa i bez hipertrigliceridemije (Mann-Whitney, P = 0.014). Zna~ajne razlike u hsCRP koncentracijama uo~ene su izme|u osoba sa povi{enim nivoima IgM aCL At i onih sa referentim vrednostima (Mann-Whitney, P = 0,028). Zaklju~ak: Dislipidemija i BMI ≥30 su bili povezani sa aPL At uprkos njihovoj niskoj prevalentnosti, i zato korekcija BMI i lipidnog statusa bi bila korisna u redukciji ili elimi- naciji predispoziraju}ih faktora koji mogu da izazovu trom- boti~ki doga|aj kod ina~e zdravih sredove~nih ispitanika. Obimnije nacionalne studije su neophodne da bi potvrdile na{e nalaze

Hyperhomocysteinemia and smoking in primary antiphospholipid syndrome

The thrombotic tendency in anti phospholipid syndrome (APS) shares several pathways with atherosclerosis. Atherothrombosis (atherosclerosis superimposed with thromboses) is influenced by nonmodifiable and some modifiable risk factors (smoking, obesity, physical inactivity, alcohol abuse, hyperhomocysteinemia). Therefore, we investigated the association among clinical and serological features of patients with primary APS and potentially modifiable risk factors for the development of atherothrombosis. Also, we compared the analyzed parameters with those in control subjects. Homo cysteine concentrations were detected by HPLC (high performance liquid chromatography), while antiphospholipid antibodies were detected by ELISA. Smokers had elevated levels of homocysteine (chi(2) = 6.22, p lt 0.05). Independently of patients' age, the association between increased levels of homocysteine and history of myocardial infarctions was found (chi(2) = 4.61, p lt 0.05). Hyperhomocysteinemia and smoking are the most important modifiable risk factors for atherothrombosis in primary APS

Uticaj ACTH, izoproterenola i deksametazona na odgovor nadbubrežne žlezde pacova na etandimetansulfonat (EDS): stereološko ispitivanje

Ethane dimethanesulphonate (EDS), an alkylating agent, caused marked atrophy of the adrenal cortex of adult male rats, in addition to its toxic effect on testicular Leydig cells. The aim of this work was to examine whether a 9-day treatment with ACTH (40 IU/kg/d), isoproterenol (120 mg/kg/d) or dexamethasone (0.25 mg/kg/d), which started 4 days prior to intraperitoneal administration of a single dose of EDS (75 mg/kg), affected the morphological changes in the adrenal cortex evoked by EDS alone. The animals were killed 15 days after EDS injection. Stereological analysis revealed that both ACTH and isoproterenol almost completely prevented cortical atrophy induced by EDS. They also considerably stimulated corticosterone secretion in EDS-injected animals. By contrast, in dexamethasone-suppressed rats, the deleterious effect of EDS on adrenocortical cells was augmented. The volume and cellularity of all cortical zones were reduced, but the remaining cells of the zona reticularis displayed considerable hypertrophy which was probably responsible for the maintenance of corticosterone secretion. These results clearly demonstrate that both ACTH and b adrenoceptor stimulation have protective action against the toxic effects of EDS on rat adrenal cortex, whereas dexamethasone exerts an opposite influence.Alkilirajući agens etandimetansulfonat (EDS), pored toksičnog delovanja na Lajdigove ćelije semenika, izaziva izraženu atrofiju kore nadbubrežne žlezde odraslih pacova. U ovom radu je ispitivan uticaj devetodnevnog tretmana sa ACTH (40 IU/kg/d), izoproterenolom (120 mg/kg/d) ili deksametazonom (0.25 mg/kg/d) na morfološke promene kore nadbubrega koje izaziva jedna intraperitonealna injekcija EDS (75 mg/kg). Tretmani su započeli 4 dana pre davanja EDS i nastavljeni su još 5 dana, a životinje su žrtvovane 15 dana posle aplikacije EDS. U prisustvu ACTH ili izoproterenola ne ispoljavaju se promene u stereološkim parametrima kore nadbubrega koje izaziva EDS. Oba tretmana značajno povećavaju i koncentraciju kortikosterona u serumu. Deksametazon, međutim, pojačava toksične efekte EDS; zapremina svih zona kore i broj parenhimskih ćelija u zonama su smanjeni, ali preostale ćelije retikularne zone pokazuju značajnu hipertrofiju, koja je verovatno odgovorna za održavanje sekrecije kortikosterona kod ovih životinja. Rezultati rada pokazuju da se toksični efekti EDS na koru nadbubrega mogu sprečiti visokim nivoom ACTH ili stimulacijom b adrenalinskih receptora, a potencirati egzogenim glukokortikoidom

Increased Glomerular Filtration Rate in Early Stage of Balkan Endemic Nephropathy

Background: A previous study indicated that Balkan endemic nephropathy (BEN) patients in the early stage of the disease had significantly higher creatinine clearance (Ccr) than healthy persons. The aim of the study was to assess whether tubular creatinine secretion affects Ccr in early stages of BEN and to check the applicability of serum creatinine-based glomerular filtration rate (GFR) equations in these patients. Methods: The study involved 21 BEN patients with estimated GFR (eGFR) above 60 mL/min/1.73 m(2), excluding any conditions that could affect GFR or tubular creatinine secretion, and 15 healthy controls. In all participants Ccr with and without cimetidine and iohexol clearance (mGFR) were measured and eGFR calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease Study (MDRD) equations. Glomerular hyperfiltration cutoff (GFR-HF) was calculated. Results: There was no significant difference between the groups in Ccr before and after cimetidine or for eGFR, but mGFR was significantly higher in BEN patients than in controls (122.02 +/- 28.03 mL/min/1.73 m(2) vs. 101.15 +/- 27.32 mL/min/1.73 m(2); p = 0.032). Cimetidine administration reduced Ccr by 10% in both groups. The ratio of Ccr to mGFR was significantly above one in seven BEN patients and five controls and their mGFR values were similar. Seven other patients and eight controls had this ratio equal to one, while values below one were recorded for seven more patients and two controls. mGFR of all these 14 patients was significantly higher than that of healthy controls (129.88 +/- 27.52 mL/min/1.73 m(2) vs. 107.43 +/- 19.51 mL/min/1.73 m(2); p = 0.009). Mean GFR-HF was significantly higher than mGFR in controls, but these two values were similar in BEN patients. eGFR underestimated mGFR in both BEN patients and controls. Conclusion: The ratio of Ccr to mGFR and mGFR to GFR-HF indicated that elevated mGFR in early stages of BEN could be explained by increased glomerular filtration, but tubular creatinine secretion augmented Ccr in a smaller proportion of patients, who did not differ from healthy subjects

Povezanost lipidnog statusa sa 25-hidroksi vitaminom D: studija preseka kod bolesnika sa krajnjim stadijumom bolesti bubrega

Background:Some observational studies indicate an association of 25-hydroxy vitamin D (25(OH)D) insufficiency and atherogenic cholesterol concentrations. The aim of this study was to investigate relationship between 25(OH)D concentrations and lipid parameters in end stage renal disease (ESRD) patients, separately for predialysis, hemodialysis and peritoneal dialysis patients.Methods:We have adjusted 25(OH)D concentrations for seasonal variability with cosinor analysis, and performed all further analysis using these corrected 25(OH)D concentrations. Concentrations of 25(OH)D and the lipid parameters were determined in 214 ESRD patients and 50 control group participants. The analysis included the measurement of 25(OH)D by HPLC, apolipoprotein (Apo) AI, ApoB andLp(a) by nephelometry, total cholesterol (TC), high-densitylipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) by spectrophotometry and manually calculated ApoB/ApoAI and LDL-C/HDL-C ratio.Results:ESRD patients with adjusted 25(OH)D concentrations of ≤ 50 nmol/L had significantly higher TC (P =0.005) and ApoAI (P = 0.049). Significantly higher HDL-C (P = 0.011) and ApoAI (P = 0.020) were found in hemodialysis patients with the 25(OH)D concentrations of ≤ 50 nmol/L. The other analyzed lipid parameters differed significantly between predialysis, hemodialysis and peritoneal dialysis patients with 25(OH)D concentrations of <50 nmol/L. Conclusions:Our study indicate the significant relationship between 25(OH)D repletion and optimal concentrations of lipid parameters in ESRD patients. Further research is necessary to explain whether joint evaluation of vitamin D status and lipid abnormalities could improve cardiovascular outcome in ESRD patients.Uvod: Opservacione studije ukazuju na povezanost nedostatka 25-hidroksi vitamin D (25(OH)D) i koncentracija aterogenog holesterola. Cilj ove studije bio je da se ispita međusobna povezanost 25(OH)D i lipidnih parametara kod bolesnika sa krajnjim stadijumom bolesti bubrega (ESRD) posebno kod predijaliznih, bolesnika na hemodijalizi i peritonalnoj dijalizi. Metode: Podesili smo koncentracije 25(OH)D za sezonsku varijaciju koristeći kosinor analizu, i u daljem ispitivanju smo koristili korigovane koncentracije 25(OH)D. Koncentracije 25(OH)D i lipidnih parametara su određene za 214 ESRD bolesnika i 50 učesnika kontrolne grupe. Analizirali smo koncentracije 25(OH)D metodom HPLC, apolipoproteina (Apo) AI, ApoB i Lp(a) nefelometrijski, ukupnog holesterola (TC), lipoproteina velike gustine (HDL-C), lipoproteina male gustine (LDL-C) i triglicerida (TG) spektro fotometrijski i ručno preračunavali indekse ApoB/ApoAI i LDL-C/HDLC. Rezultati: ESRD bolesnici sa korigovanim 25(OH)D 50 nmol/L su imali značajno viši TC (P = 0,005) i ApoAI (P = 0,049). Značajno više koncentracije HDL-C (P = 0,011) i ApoAI (P = 0,020) smo dobili kod hemodijaliznih bolesnika sa 25(OH)D koncentracijama 50 nmol/L. Ostali analizirani lipidni parametri su bili značajno različiti između analiziranih grupa bolesnika sa 25(OH)D koncentracijama < 50 nmol/L. Zaključak: Naša studija ukazuje na značajnu povezanost dovoljnih nivoa 25(OH)D i optimalnih koncentracija lipidnih parametara kod ESRD bolesnika. Potrebna su dalja istraživanja da bi se objasnilo da li zajednička procena statusa vitamina D i lipidnih abnormalnosti mogu da poboljšaju kardiovaskularni ishod kod ESRD bolesnika

Questionable reliability of homocysteine as the metabolic marker for folate and vitamin B12 deficiency in patients with chronic obstructive pulmonary disease

Uvod: Povišena koncentracija homocisteina (Hey) može predstavljati metabolički marker nedostatka folata i vitamina B12, značajnih problema javnog zdravlja. Bolesnici sa hroničnom opstruktivnom bolešću pluća (HOBP) skloni su nedostatku ovih vitamina usled različitih razloga. Prikazana studija procenjuje pouzdanost koncentracije Hcy kao prediktora nedostatka folata i vitamina B12 kod ovih bolesnika. Metode: Studija je sprovedena u grupi od 50 osoba obolelih od HOBP (28 muškaraca/22 žene, starosti (x±SD = 49,0±14,5) godina. Koncentracije Hcy, folata i vitamina B12 su određivane hemiluminiscentnim imunoodređivanjem na mikročesticama. Statistička analiza je uključila testove Kolmogorov-Smirnov, Mann-Whitney U and x2, Spearman-ovu korelaciju i ROC analizu, uz nivo značajnosti od 0,05. Rezultati: Prosečne (SD) koncentracije folata i vitamina B-12 su iznosile 4,15 (2,16) pg/L i 465,6 (271,0) ng/L, pri čemu je samo kod vitamina B12 uočena korelacija sa nivoom Hcy (R =-0,510 (P=0,029)). Koncentracije vitamina se nisu razlikovale između polova, a starost je bila u korelaciji samo sa nivoom folata (R= 0,279 (P=0,047)). Incidenca nedostatka vitamina značajno se razlikovala (P=0,000 i P lt 0,000 za folat odn. vitamin B12) u zavisnosti od cut-off vrednosti u odnosu na koju je definisana (4,4; 6,6 i 8,0 pg/L - folat; 203 i 473 ng/L - vitamin B-12)-ROC analizom nije bilo moguće dokazati značaj hiperhomocisteinemije kao prediktora deficijencije. Zaključak: Pouzdanost koncentracije Hey kao markera nedostatka folata ili vitamina B12 kod bolesnika sa HOBP nije zadovoljavajuća, pa se deficijencija ovih vitamina ne može predvideti na osnovu pojave hiperhomocisteinemije.Background: An increased homocysteine (Hey) concentration may represent a metabolic marker of folate and vitamin Bi2 deficiency, both significant public health problems. For different reasons, patients with chronic obstructive pulmonary disease (COPD) are prone to these deficiencies. The study evaluates the reliability of Hey concentration in predicting folate or vitamin B12 deficiency in these patients. Methods: A group of 50 COPD patients (28 males/22 females, age (x±S D = 49.0±14.5) years was enrolled. A chemiluminescent microparticle immunoassay was applied for homocysteine, folate and vitamin B12 concentration. Kolmogorov-Smirnov, Mann-Whitney U and x2 tests, Spearman's correlation and ROC analysis were included in the statistical analysis, with the level of significance set at 0.05. Results: Average (SD) concentrations of folate and vitamin B12 were 4.15 (2.16) pg/L and 465.6 (271.0) ng/L, whereas only vitamin B12 correlated with the Hey level (P =-0.510 (R=0.029)). Gender related differences were not significant and only a borderline significant correlation between age and folate was confirmed (R = 0.279 (P=0.047)). The incidence of folate and vitamin B12 deficiency differed significantly (P=0.000 and PcO.OOO for folate and vitamin B12 respectively), depending on the cutoff used for classification (4.4, 6.6 and 8.0 pg/L - folate; 203 and 473 ng/L - vitamin B12)-ROC analyses failed to show any significance of hyperhomocysteinemia as a predictor of folate or vitamin B12 deficiency. Conclusion: Reliability of the Hey concentration as a biomarker of folate or vitamin B12 depletion in COPD patients is not satisfactory, so their deficiency cannot be predicted by the occurrence of HHcy

Role of serotonin in development of esophageal and gastric fundal varices

AIM: To determine the effect of free serotonin concentrations in plasma on development of esophageal and gastric fundal varices. METHODS: This prospective study included 33 patients with liver cirrhosis and 24 healthy controls. Ultrasonography and measurement of serotonin concentration in plasma were carried out in both groups of subjects. The upper fiber panendoscopy was performed only in patients with liver cirrhosis. RESULTS: The mean plasma free serotonin levels were much higher in liver cirrhosis patients than in healthy controls (219.0 +/- 24.2 nmol/L vs 65.4 +/- 18.7 nmol/L, P lt 0.0001). There was no significant correlation be-tween serotonin concentration in plasma and the size of the esophageal varices according to Spearman coefficient of correlation (r(s) = -0.217, P > 0.05). However, the correlation of plasma serotonin concentration and gastric fundal varices was highly significant (r(s) = -0.601, P lt 0.01). CONCLUSION: Free serotonin is significant in pathogenesis of portal hypertension especially in development of fundal varices, indicating the clinical value of serotonergic receptor blockers in these patients

Poređenje tri različite metode za određivanje 25(OH)-vitamina D i statusa vitamina D u opštoj populaciji - srpsko iskustvo

Determination of 25-hydroxyvitamin D [25(OH)D] represents a unique challenge, considering its lipophilic nature. Considering the widespread prevalence of vitamin D deficiency, which leads to increasing number of requests for 25(OH)D determination, immunoassay measurements adjusted to automated analyzers are being developed. Because of the variability among assays, it is often difficult to monitor vitamin D status and supplementation. The aim of this study was to compare the results of two immunoassays with high performance liquid chromatography with ultraviolet detection (HPLC-UV). Also, the aim was to estimate vitamin D status, since up to date the prevalence of vitamin D deficiency in Serbia was not examined. We have evaluated analytical characteristics of two automated immunoassays for 25(OH)D determination, from Roche (Cobas® e601) and Abbott (Architect). For comparison studies we used HPLC analysis of 25-(OH)-Vitamin D3/D2 from Chromsystems (Waters isocratic system). In order to estimate vitamin D status in general population, we have searched the database of the laboratory information system and analyzed the data from 533 patients whose 25(OH)D was determined together with intact parathyroid hormone (iPTH). For imprecision assessment, four serum pools were prepared with following 25(OH)D concentrations: 35 nmol/L, ?50 nmol/L, ?75 nmol/L and ?125 nmol/L. Obtai ned CVs for Roche method were 1.5-2.8% for within-run and 4.0-6.7% for between-run imprecision. For Abbott method, CVs were 0.7-4.4% for withinrun and 3.8-7.2% for between-run imprecision. Inaccuracy was analyzed with commercial control sera. Obtained deviations from target value were 2.1% for Roche assay and 1.3-1.5% for Abbott method, and were not statistically significant (P>0.05). Comparison of Roche and HPLC-UV methods using Passing-Bablok regression analysis gave the following equation for the regression line y=0.937x+9.518 (r=0.739; n=97) and the regression line equation from the comparison of Abbott and HPLC-UV methods was y=0.745x+10.343 (r=0.793; n=97). Mean difference and SD for Bland-Altman plot were -4.5 nmol/L and 21.75 nmo/L, respectively for Roche method and 6.4 nmol/L and 18.8 nmol/L, respectively for Abbott. Statistical analysis (Chi-square test) of frequency distribution among different vitamin D status categories ( lt 25 nmol/L severe deficiency, 25-50 nmol/L deficiency, 50-75 nmol/L insufficiency and >75 nmol/L sufficiency) showed that the frequency distribution obtained with Abbott method was significantly different from the distribution of the HPLC results, in contrast to Roche results frequency distribution which did not differ significantly. Also, statistical analysis of the agreement between the three methods for each vitamin D status category showed that results of both Roche and Abbott methods were significantly higher than HPLC in the two deficiency categories (P=0.005 for Roche, P=0.0407 for Abbott), and in the sufficiency category Abbott method significantly underestimated concentration of 25(OH)D compared to HPLC results (P lt 0.0001). Median population values of 25(OH)D and iPTH were 41.8 nmol/L and 76.6 ng/L, respectively. ANOVA analyses showed significant (P lt 0.05) decrease in iPTH and Ca2+ concentrations across the 25(OH)D concentration categories. Stepwise multiple linear regression analysis indicated independent correlation of iPTH with 25(OH)D concentration (b=-0.290, P=0.0008). Also, one-way ANOVA with Student-Newman-Keuls test demonstrated that 25(OH)D concentrations measured in summer and autumn were significantly (P lt 0.001) higher compared to those determined in winter and spring. Despite acceptable imprecision and inaccuracy of both examined methods, results obtained with them did not correlate well with HPLC-UV (r lt 0.9), which was used as a reference. However, methods showed satisfactory ability to classify patients into vitamin D status categories, which is important for diagnosis of vitamin D deficiency and therapy follow-up. About two thirds (68.5%) of the examined population had vitamin D deficiency (25(OH)D lt 50 nmol/L) and only 8% had sufficient 25(OH)D concentration (>75 nmol/L).Određivanje 25-hidroksivitamina D [25(OH)D] predstavlja jedinstven izazov, s obzirom da je visoko lipofilno jedinjenje. Visoka prevalencija deficijencije vitamina D uzrok je povećanja broja zahteva za određivanjem 25(OH)D, zbog čega se razvijaju imunohemijske metode prilagođene automatizovanim sistemima. Često je teško pratiti status vitamina D i suplementaciju zbog varijabilnosti između testova. Cilj ove studije bio je da se uporede rezultati dve imunohemijske metode sa tečnom hromatografijom visoke efikasnosti sa detekcijom u ultraljubičastom delu spektra (HPLC-UV). Takođe, cilj je bio i procena statusa vitamina D, pošto do sada nije ispitivana prevalencija deficijencije vitamina D u Srbiji. Ispitivane su karakteristike dve imunohemijske metode za određivanje 25(OH)D, proizvođača Roche (analizator Cobas® e601) i Abbott (na analizatoru Architect). Metode su poređene sa rezultatima HPLC analize korišćenjem 25-(OH)-Vitamin D3/D2 reagenasa firme Chromsystems (Waters izokratski sistem). Da bi se procenio status vitamina D u opštoj populaciji, pretražena je baza podataka laboratorijskog informacionog sistema i analizirani su rezultati 533 pacijenata kojima je određen 25(OH)D zajedno sa intaktnim paratiroidnim hormonom (iPTH). Pripremljena su četiri serumska pool-a sa koncentracijama 25(OH)D ? 35 nmol/L, ?50 nmol/L, ?75 nmol/L i ?125 nmol/L za procenu nepreciznosti imunohemijskih određivanja. Dobijeni koeficijenti varijacije za Roche metodu su se kretali u opsegu 1,5-2,8% u seriji i 4,0-6,7% između serija. Za Abbott metodu su koficijenti varijacije iznosili 0,7-4,4% u seriji i 3,8-7,2% između serija. Netačnost je ispitivana pomoću komercijalnih kontrolnih uzoraka. Dobijena odstupanja od deklarisane vrednosti su iznosila 2,1% za Roche i 1,3-1,5% za Abbott, i nisu bila statistički značajna (P>0,05). Poređenjem Roche i HPLC-UV metoda pomoću Passing-Bablok regresione analize dobijena je sledeća regresiona jednačina y=0,937x+9,518 (r=0,739; n=97), dok regresiona jednačina dobijena poređenjem Abbott i HPLC-UV metoda glasi y=0,745x+10,343 (r=0,793; n=97). Srednja vrednost razlika na Bland-Altman dijagramu razlika i standardna devijacija su iznosile -4,5 nmol/L i 21,75 nmo/L, redom, za Roche metodu i 6,4 nmol/L i 18,8 nmol/L, re dom, za Abbott metodu. Statistička analiza (Chi-kvadrat test) distribucije frekvencija među različitim kategorijama statusa vitamina D ( lt 25 nmol/L teška deficijencija, 25-50 nmol/L deficijencija, 50-75 nmol/L insuficijencija i >75 nmol/L preporučena koncentracija) je pokazala da je distribucija frekvencija dobijena Abbott metodom značajno različita od distribucije HPLC rezultata, za razliku od ras po dele frekvencija dobijene Roche metodom koja se nije značajno razlikovala. Takođe, statistička analiza slaganja između ispitivane tri metode u svakoj od kategorija statusa vitamina D je pokazala da su rezultati i Roche i Abbott metoda značajno veći od HPLC-UV u kategorijama deficijencije vitamina D (P=0,005 za Roche; P=0,0407 za Abbott), i u kategoriji sa preporučenom koncentracijom vitamina D Abbott metoda je značajno potcenjivala koncentraciju 25(OH)D u poređenju sa HPLC rezultatima (P lt 0,0001). Medijana za 25(OH)D u ispitivanoj populaciji bila je 41,8 nmol/L, i 76,6 za iPTH. ANOVA analiza je pokazala značajan pad (P lt 0,05) koncentracija iPTH i jonizovanog kalcijuma između kategorija koncentracija 25(OH)D. Multiplomlinearnom regresionom analizom utvrđena je ne zavisna korelacija između koncentracija iPTH i 25(OH)D (b =-0,290; P=0,0008). Takođe, ANOVA za jedan kriterijum klasifikacije sa Student-Newman-Keuls testom je pokazala da su koncentracije 25(OH)D određene u leto i jesen značajno više (P lt 0,001) u poređenju sa onima određenim u zimu ili proleće. Uprkos prihvatljivoj nepreciznosti i netačnosti obe ispitivane imunohemijske metode, dobijeni rezultati nisu u zadovoljavajućoj korelaciji sa HPLC-UV metodom (r lt 0,9), koja je korišćena kao referentna u ovom slučaju. Uprkos ovoj činjenici, metode su pokazale zadovoljavajuću sposobnost klasifikacije pacijenata u kategorije statusa vitamina D, što je važno za dijagnozu deficijencije vitamina D i praćenje terapije. Oko dve trećine (68,5%) ispitivane populacije je imalo deficijenciju vitamina D (25(OH)D lt 50 nmol/L) i samo 8% je imalo preporučenu koncentraciju 25(OH)D (>75 nmol/L)

Introduction to Molecular genetic diagnostics

Molecular genetic testing is part of modern medical practice. DNA tests are an essential part of diagnostics and genetic counseling in single gene diseases, while their application in polygenic disorders is still limited. Pharmacogenetics studies DNA variants associated with variations in drug efficacy and toxicity, and tests in this field are being developed rapidly. The main method for molecular genetic testing is the polymerase chain reaction, with a number of modifications. New methods, such as next generation sequencing and DNA microarray, should allow simultaneous analysis of a number of genes, even whole genome sequencing. Ethical concerns in molecular genetic testing are very important, along with legislation. After molecular genetic testing, interpretation of results and genetic counseling should be done by professionals. With the example of thrombophilia, we discuss questions about genetic testing, its possibilities and promises