Enhanced International Prognostic Index (NCCN-IPI), Charlson Comorbidity Index and absolute lymphocyte count as predictors for survival of elderly patients with diffuse large B cell lymphoma treated by immunochemotherapy.

Diffuse large B cell lymphoma (DLBCL) affects more commonly patients over 60 years. These patients have vast number of comorbidities which can modify survival as well as other clinical parameters. The aim of this study was to evaluate prognostic significance of the National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI), absolute lymphocyte count (ALC), absolute monocyte count (AMC), lymphocyte-to-monocyte ratio (LMR) and comorbidities expressed with Charlson Comorbidity Index (CCI). A total of 182 DLBCL patients 60 years old and older were included, focusing on whole group and patients older than 70. All patients were treated with immunochemotherapy.Overall treatment response was achieved in 84.6% of patients. The NCCN-IPI was of highly prognostic value in the analyzed group (p<0.0001). Survival analysis showed that ALC>1.1x109/L, AMC≤0.59x109/L, and LMR>2.8 were associated with more favorable outcome (p=0.029, p=0.019, p=0.028, respectively). The patients with CCI≥2 had poorer outcome (p=0.008) compared to the patients with CCI 0-1. Multivariate analysis showed that among ALC, AMC, LMR, NCCN-IPI and CCI, the NCCN-IPI was the critical parameter that significantly affected survival (p<0.0001). Furthermore, comorbidities were also valuable independent factors which influenced survival (p=0.031) as well as the ALC (p=0.024). In elderly DLBCL patients, NCCN-IPI and ALC proved their prognostic validity, while poorer outcome could be expected in older patients with high CCI (≥2). Furthermore, mentioned prognostic parameters retained their prognostic value in the group of patients older than 70.

C-reactive protein as an early predictor for anastomotic leakage in elective abdominal surgery.

BACKGROUND: Anastomotic leakage (AL) represents a serious complication after abdominal surgery. Therefore, it is important to detect it early before it becomes clinically apparent. The predictive value of C-reactive protein (CRP) as a marker of infective postoperative complications, particularly in the form of anastomotic leakage, has been investigated by several authors with promising results. The aim of this study was to evaluate the diagnostic accuracy of C-reactive protein in predicting anastomotic leakage. METHODS: The serum CRP level, white blood cell (WBC) count, and body temperature (BT) of 156 patients who underwent elective abdominal surgery with primary anastomosis were monitored daily until postoperative day (POD) 7. We recorded all postoperative complications and analyzed the data. Diagnostic accuracy of CRP with regard to development of AL was assessed by receiver operating characteristic curve analysis. RESULTS: Fifteen patients (9.6 %) developed anastomotic leakage. CRP was significantly higher every day during the first 7 postoperative days in patients who developed AL compared with those patients who did not develop complications, whereas the WBC count and BT were not. A CRP cutoff value of 135 mg/l on POD 3 yielded a sensitivity of 73 %, a specificity of 73 %, and a negative predictive value of 95.4 % for the detection of AL. CONCLUSIONS: According to our results, values of CRP less than 135 mg/l on POD 3 may contribute to a safe discharge from hospital. Patients with CRP values higher than 135 mg/l on POD 3 require prolonged hospitalization and an intensive search for infective complications, particularly AL.

The clinical value of scintigraphy of neuroendocrine tumors using (99m)Tc-HYNIC-TOC.

PURPOSE: To assess the value of whole body scintigraphy using (99m)Tc-HYNIC-TOC (Tektrotyd) and with single photon emission computerized tomography (SPECT) in the detection of primary and metastatic neuroendocrine tumors (NETs). METHODS: Thirty patients with different neuroendocrine tumors, mainly gastroenteropancreatic (GEP), were investigated. Whole body scintigraphy was performed 2 h (if necessary 10 min and 24h) after i.v. administration of 740 Mbq (99m)Tc-Tektrotyd, Polatom. In cases of unclear findings obtained by whole body scintigraphy, investigation was followed by SPECT. RESULTS: From 12 patients with NETs of unknown origin, there were 10 true positive (TP), and 2 false negative (FN) findings. Diagnosis was made with SPECT in 6 patients. From 8 patients with gut carcinoids, there were 4 TP, 2 true negative (TN), one FN, and one false positive (FP) finding. Diagnosis was made with SPECT in 2 patients. From 7 patients with neuroendocrine pancreatic carcinomas there were 4 TP and 3 TN findings. Diagnosis was made with SPECT in 2 patients. From 3 patients with gastrinomas there were 2 TP findings and one TN findings. Diagnosis was made with SPECT findings in 2 patients. Sensitivity of (99m)Tc-HYNIC-TOC was 87%, specificity 86%, positive predictive value 95%, negative predictive value 67% and accuracy 87%. CONCLUSION: We concluded that scintigraphy with (99m)Tc-Tektrotyd is an useful method for diagnosis, staging and follow up of the patients with NETs.

Evaluation of the Alvarado score in the diagnosis of acute appendicitis.

This study has been performed in the Emergency center, Clinical centre of Serbia, during the period 01.03.2007-01.09.2007. We performed this study on 57 patients with diagnosis suspected for acute appendicitis (ages 16-70). Parameters that make the Alvarado score are the following: migration of pain, anorexia, nausea or vomiting, right lower abdominal quadrant tenderness, rebound tenderness in right iliac fossa, elevated temperature, leukocytosis, shift to the left of neutrophils. The aim of the work is to evaluate the Alvarado scoring system in diagnosis of the acute appendicitis. With all the patients Alvarado score has been determinate preoperatively, and diagnosis was confirmed by intraoperative finding and histopatological examination of the removed appendix. All the patients with score 7 or more were surgically managed. Specificity (positive predictive value) was 92.59 % in males and 76.67 % in females. The negative appendectomy rate was 7.41 % with the males and 23.33 % with the females. The values of the Alvarado score are significantly higher in the patients with acute appendicitis, compared with the patients of the other diseases. With the application of the Alvarado scoring system we can decrease postoperative morbidity and mortality.

[Influence of tumor size and intestinal wall invasion on development of colorectal liver metastases].

While the general prognostic factors for colorectal carcinoma have been widely researched, the compound relationships between tumor characteristics and development of colorectal liver metastases have not been clearly understood. The aim of this study was to determine which histopathological characteristics of colorectal cancer may be associated with subsequent development of colorectal liver metastases. We performed retrospective and prospective study which included 80 patients operated for colorectal carcinoma on the First Surgical Clinic of Clinical Center of Serbia in Belgrade. Retrospective group consisted of 40 patients operated between 1992. and 1996. while prospective group included 40 patients treated between 1997. and 2001. We analyzed the size of the tumor, depth of invasion through the intestinal wall, extramural spread of the tumor, infiltration of blood vessels and lymphatics, lymph node involvement, tumor maturation and growth, as well circumferential intestinal involvement. Statistical analysis performed showed highly significant (p<0,01) correlation between the tumor size, degree of maturation of the tumor, extramural spread and involvement of the venules with later development of colorectal liver metastases in both groups.

[Surgical treatment of hematologic disorders of the spleen]. / Hirursko lecenje hematoloskih oboljenja slezine.

Splenectomy--the surgical removal of spleen is being performed in cases of: traumatic spleen rupture, as part of other surgical procedures, number of hematological, infectious and metabolic disorders. During the years 1988.-2001., there were 396 splenectomies performed at the First surgical clinic, for the cause of: autoimmune disorders 187 (47.34%), lymphoproliferative diseases 89 (22.59%). Hodgkin disease 35(8.94%), myeloproliferative disease 39 (9.95%), as part a of "staging" laparotomy 37(9.34%), other hematological disorders 7(2.20%). The spleen of [table: see text] 244 patients weighted 500-1500 g(61.62%), in 56 patients (14.14%) weighted less than 500 g, and in 96 patients (24.24%) spleen weighted more than 1500 g. Patients with thrombocytes less than 40,000/l 16 (4.04%) were perioperativly treated with fresh thrombocytes. Postoperative morbidity and mortality were registered in 54 (13.64%), i.e. 8 (2.02%) patients. Delayed results depended on primary disorder, comorbidities and supportive therapy. In this article, the particularities of the operative procedure were discussed, as well as importance of cooperation of surgeon and hematologist in perioperative treatment.

Effect of dialysis dose on nutritional status of children on chronic hemodialysis.

It had been suggested that larger hemodialysis (HD) doses in children could result in better appetite, higher protein intake, better nutritional status and better growth. We investigated how different HD doses affect protein intake and nutritional status of children on chronic HD. Indices of nutritional status used were normalized protein catabolic rate (nPCR) calculated by formal 3-sample urea kinetic modeling and serum albumin level. Data of 38 HD sessions in 15 stable patients (6 males, 9 females) aged 14.5 +/- 3.28 years (mean +/- SD) were analyzed. HD sessions were divided into three groups based on delivered Kt/V: group 1 (n = 5), inadequate (Kt/V < 1.3, mean 1.05 +/- 0.14); group 2 (n = 12), adequate (Kt/V = 1.3-1.6, mean 1.50 +/- 0.07) and group 3 (n = 21), high (Kt/V >1.6, mean 1.94 +/- 0.22). Mean nPCR and Kt/V per patient during the studied week were estimated for 11 patients in whom 3 HD sessions were available within the 38 sessions analyzed. Serum albumin level was adequate in all patients (43.77 +/- 2.28 g/l). Mean overall Kt/V and nPCR were 1.68 +/- 0.36 and 1.26 +/- 0.23, respectively, r = 0.430. Average nPCR differed between groups depending on Kt/V. It was lowest in group 1 (1.01 +/- 0.12 g/kg/day) where the highest correlation between nPCR and Kt/V was found (r = 0.648). nPCR was higher and similar in groups 2 (1.27 +/- 0.23 g/kg/day) and 3 (1.31 +/- 0.22 g/kg/day), with low correlation coefficients between nPCR and Kt/V in both groups (r = 0.275 and r = 0.197, respectively). A weak positive correlation (r = 0.249) between nPCR and Kt/V was found when average weekly values per patient (n = 11) were analyzed. Results of groups 1 and 2 confirm, what is already well established in adults, that adequate dialysis needs to be achieved in order to insure good protein intake. However, our data clearly show that nPCR did not increase with a further increase in delivered HD dose, i.e. Kt/V >1.6. Our results show that the nutritional status of children on chronic HD does not seem to benefit from very high HD doses (Kt/V >1.6).

[The Lesch-Nyhan syndrome]. / Les-Nijanov (Lesch-Nyhan) sindrom.

Deficiency of hypoxanthine phosphoribosyltransferase (HPRT) has a broad spectrum of clinical manifestations, from the complete enzyme defect, the Lesch-Nyhan syndrome with severe neurological deficiency to the partial defect associated only with uric acid overproduction and its consequences. We present a 5-year old boy with Lesch-Nyhan syndrome. He came to our hospital because of abdominal pain, vomiting and gross haematuria. At the age of 8 months he was categorized as a "cerebral palsy" patient due to involuntary movements and high degree of spastically and tonic spasms. He remained incapable of sitting or standing alone. The patient's brother and two uncles were also categorized as "cerebral palsy" cases and died at the age of 8-14 years. Clinical examination revealed hyperuricaemia and hyperuricosuria, radiolucent renal and urinary bladder stones. HPRT enzyme activity was totally absent, while adenine phosphoribosyl transferase activity was increased compared to control. The patient was treated with allopurinol, urinary alkalization, low-purine diet and adequate hydration while he was in hospital. However, his parents refused further treatment and follow-up. The most important issue is whether the healthy sisters of the patients are heterozygotes for HPRT deficiency. This DNA analysis is now in progress.

[Bartter's syndrome: new classification, old therapy]. / Barterov sindrom: nova podela, stara terapija.

We report on two cases of Bartter's syndrome, together with the review of current literature on the aetiology, development and treatment of Bartter's syndrome. Bartter's syndrome belongs to a group of hypokalaemic renal channelopathies, which are caused by a molecular hereditary disorder of ion channels in renal tubules. These channels are located in the lipid layer of cell membranes where they exist as water channels through which ion transport is performed. Based on the type of genetic disorder and clinical presentation, Bartter's syndrome is classified as neonatal, classical and Gitelman's syndrome. Neonatal form is found in newborns and is characterized by foetal polyuria, premature birth, postnatal episodes of severe dehydration, growth retardation, hypercalciuria and early nephrocalcinosis. It is the result of mutation of a gene responsible for renal tubular Na-K-2Cl cotransport or another gene which controls the ATP-dependant potassium channel (ROMK). Classic form is found in young children with polyuria, hypokalaemia and growth retardation. This type is caused by a defect of a gene for chloride channel (CIC-Kb) in the distal tubule. Gitelman's syndrome is found in late childhood or adolescence. It is caused by mutation in the gene for Na-Cl co-transport in the distal tubule. Children with Gitelman's syndrome occasionally have muscle weakness or tetany, hypokalaemia and hypomagnesaemia. Even though there have been advances in understanding the aetiology and pathogenesis of Bartter's syndrome in the recent years, the possibilities and strategies for its management remained almost the same. Treatment is based on prostaglandin inhibitors, potassium sparing diuretics and substitution therapy.

Prediction of equilibrated urea in children on chronic hemodialysis.

Urea rebound (UR) after hemodialysis (HD) requires the use of equilibrated urea (Ceq) instead of immediate end-dialysis urea (Ct) for correct quantification of HD, which is impractical. A new formula for predicting Ceq in children is suggested in our study. Thirty eight standard pediatric HD sessions (single pool Kt/V = 1.70 +/- 0.35, K = 4.65 +/- 1.14 ml/min/kg, UF coeff. = 3.2-6.2 ml/h/mm Hg, t = 3.80 +/- 0.46 h) in 15 children (M: 6, F: 9), ages 14.5 +/- 3.28 years were analyzed. Blood samples were taken: before, 70 min from the start, at the end, and 60 min after the end of HD sessions. After correlating UR (20.32 +/- 7.74%) to various HD parameters, we found that it was mainly determined by HD efficiency parameters. Therefore we correlated Ceq to HD efficiency parameters (Ct, urea reduction ratio, Kt/V, and K/V) and found a very high correlation between Ct and Ceq (r = 0.973). Linear regression analysis was used to further investigate this relationship, and a new formula to predict Ceq from Ct was obtained (Ceq = 1.085 Ct + 0.729, R2 = 0.946, SE = 0.49, absolute residuals = 0.38 +/- 0.29 mmol/L). In a validation study (10 HD sessions with new set of urea blood samples) the results obtained by the new formula were compared with measured values of Ceq and those obtained by the Smye formulae. Values predicted by the new formula (9.91 +/- 2.92 mmol/L) were not significantly different from the measured values (10.33 +/- 3.44 mmol/L). Absolute error of the new formula was 0.78 +/- 0.73 mmol/L, median 0.65; ie., 6.93 +/- 5.3%, median 7.7%. Ceq predicted by the Smye formulae (10.95 +/- 4.18 mmol/L) also did not significantly differ from the measured values, but absolute error of predicted values was markedly higher (1.21 +/- 0.90 mmol/L, median 0.89; 11.73 +/- 7.72%, median 10.11%; p < 0.05). When predicted Ceq was used for calculating equilibrated Kt/V (eKt/V), the new formula resulted in lower absolute error (0.09 +/- 0.07, median 0.08) than the Smye method (0.14 +/- 0.08, median 0.12). We conclude that our simple formula is sufficiently accurate in predicting Ceq in standard pediatric HD and that it is more accurate than the existing Smye formulae, while requiring only pre- and post-HD urea samples. We suggest the use of the new formula for predicting Ceq, which can then be used instead of Ct for a more accurate estimation of double pool Kt/V, URR, V, and PCR.

Engagement of the scavenger receptor is not responsible for beta-amyloid stimulation of monocytes to a neurocytopathic state.

Experiments were performed to determine if scavenger receptors (SRs) play a role in amyloid beta (Abeta) stimulation of peripheral blood monocyte (PBM) neurotoxicity. Results indicate that Abeta does not block binding of the SR ligand DiI-acetylated low density lipoprotein to PBM, nor does another SR ligand, fucoidin, inhibit Abeta-PBM binding. Moreover, neither of three SR ligands alone stimulates neurotoxicity in PBM, nor antagonizes the ability of Abeta to activate PBM to a neurocytopathic state. Such findings suggest that Abeta's action is not dependent upon engagement of the SR ligand binding domain and raise doubts about the role of SR in Abeta neurotoxicity.

Effects of postdialysis urea rebound on the quantification of pediatric hemodialysis.

Urea rebound (UR) causes single pool urea kinetic modeling (UKM), which is based on end-dialysis urea instead of its equilibrated value (Ceq), to erroneously quantify hemodialysis (HD) treatment. We estimated the impact of postdialysis UR on the results of formal variable volume single pool (VVSP) UKM [Kt/V, urea distribution volume (V), urea generation rate (G), normalized protein catabolic rate (nPCR), and urea reduction ratio (URR)] in children on chronic HD. Thirty-eight standard pediatric HD sessions in 15 stable patients (9 female, 6 male) aged 14.5 +/- (SD) 3.28 years were investigated. The HD sessions lasted 3.75 +/- 0.43 h. The single pool urea clearance was 4.84 +/- 1.25 ml/min/kg. All HD sessions were evaluated by VVSP and URR (%) with postdialysis urea taken at the end of HD and with Ceq taken 60 min after the end of HD, incorporating double pool effects and representing true double pool values. The anthropometric V was calculated by Cheek and Mellits formulae for children. VVSP significantly overestimated Kt/V by 0.26 +/- 0.18 U (1.68 +/- 0.36 vs. 1.42 +/- 0.30, p < 0.0001), i.e., 19. 05 +/- 13.07%, G/V (0.20 +/- 0.04 vs. 0.18 +/- 0.04, p < 0.0001), nPCR (1.26 +/- 0.23 vs. 1.18 +/- 0.22 g/kg/day, p < 0.0001), and URR (73.92 +/- 6.49 vs. 69.22 +/- 7.06, p < 0.0001). VVSP significantly underestimated kinetic V in comparison to anthropometric V (18.74 +/- 4.04 vs. 20.76 +/- 4.43 liters or expressed as V/body weight: 58 +/- 8 vs. 65 +/- 9%, p < 0.05), while double pool kinetic V was more accurate (21.45 +/- 4.34 liters, V/body weight: 64 +/- 6%, p > 0.05). We conclude that UR has a significant effect on all results of UKM even after standard pediatric HD, and the degree of this efffect is documented. We suggest an increase of the minimum required prescribed single pool Kt/V in children and reduction of any delivered single pool Kt/V by approxiamtely 0.26 Kt/V U. Overestimation of nPCR by approximately 0.08 g/kg/day and underestimation of V by 8.5% should be kept in mind.

Hyponatremic hypertensive syndrome.

We report on a 4-year-old girl with hyponatremic-hypertensive syndrome (HHS), a rare entity in childhood. The girl was referred to us from a local hospital with a history of recurrent fever, vomiting, and seizures. On admission she was markedly dehydrated. Initial investigations revealed severe hyponatremia (serum Na 120 mmol/l), hypochloremia (serum Cl 68 mmol/l), and mild hypokalemia (serum K 3.3 mmol/l), while serum calcium and magnesium were normal. Serum urea was 5 mmol/l and serum creatinine was 62 mumol/l. Despite hyponatremic dehydration, her urine output was high (2050 ml/24 h), as was her urinary sodium (168 mmol/24 h). She had massive transient proteinuria (maximal 1642 mg/24 h) while being severely hypertensive (blood pressure 210/160 mmHg). Further investigations revealed right kidney scarring, hyper-reflexive bladder dysfunction, massive brain infarcts, and myocardial left ventricular hypertrophy. Renal arteries were normal on arteriography. Blood pressure control resulted in normalization of serum and urinary electrolytes and decrease of proteinuria. Hyponatremia and transient massive proteinuria in this patient seem to be caused by high-pressure-forced diuresis due to malignant renoparenchymal hypertension.

[20 years' experience in the treatment of children with terminal renal insufficiency in Yugoslavia]. / Dvadesetogodisnje iskustvo u lecenju dece s terminalnom insuficijencijom bubrega u Jugoslaviji.

The first specialized haemodialysis (HD) paediatric centre in former Yugoslavia was established at the University Children's Hospital in Belgrade in January 1980. A total of 194 children (F: 98, M: 96), aged less than 19 years (10.12 +/- 4.23), were treated for renal replacement therapy (RRT) over 20 years. Average annual incidence rate was 1.59 per million of child population (pmcp) aged less than 19 years for the period 1980-1990 (former Yugoslavia) and 2.85 pmcp aged less than 19 years for the period 1990-2000 (present Yugoslavia). Reflux nephropathy was the most frequent underlying disease and accounted for 37.06% of total cases, while other primary renal diseases were: glomerulonephritis (GN) 17.26%, cystic/hereditary familial nephropathy 12.69%, congenital disease 11.68%, interstitial nephritis 5.58%, non-recovered tubular necrosis 3.55%, secondary GN 1.52% and 10.66% remained with doubtful diagnosis. HD was the first RRT in 84.02%, peritoneal dialysis (PD) in 14.43% and pre-emptive transplantation in 1.55% of all patients. A total of 53 patients (27.3% of total terminal renal failure (TRF) patients) received 56 kidney transplants (58.93% live related, 37.50% cadaveric, 3.57% live-non related). Actual survival in RRT was 64.53% 5 in years; 51.68% in 10 and 48.23% in 15 years. Patient survival in HD was significantly better over the last ten-year period than in the first ten-year period (35.88% vs. 75.75%; p < 0.005) as well as the survival of transplanted patients in the same two periods (67.62% vs. 95.45%). Graft survival was 79.85% in 5 and 70.50% in 10 years. Cardiovascular complications were the most common cause of death of patients on RRT (56.10 posto) followed by infection (24.39). On December 31, 1999, 54 patients on RRT were alive less than 19 years: 75.92% in HD; 22.22% with functioning graft and 1.85% on automatic PD. This is the first national-wide long-term study of incidence and aetiology of paediatric TRF and outcome of paediatric RRT in Yugoslavia.

Comparison of two methods for predicting equilibrated Kt/V (eKt/V) using true eKt/V value.

Two methods have been suggested by Daugirdas and Schneditz (the rate equation), and Smye for predicting true equilibrated Kt/V (eKt/V) without the need for obtaining a blood sample 60 min after hemodialysis (HD). We compared the accuracy of these two methods when applied to pediatric HD. Thirty-eight standard pediatric HD sessions in 15 patients, (6 male, 9 female), aged 14.5+/-3.3 years, were analyzed. Kt/V was calculated by formal variable-volume single-pool urea kinetic model with post-HD urea taken at the end of HD (single-pool Kt/V), and with equilibrated urea (Ceq) taken 60 min after the end of HD (eKt/V). eKt/V was predicted by the rate equation from single-pool Kt/V and by the Smye method from predicted Ceq. Mean values obtained by both the rate equation (1.44+/-0.32, P>0.05) and by the Smye method (1.47+/-0.36, P>0.05) were similar to eKt/V (1.42+/-0.30), but correlation between results from the rate equation and eKt/V (r=0.863) was higher than between those from the Smye method and eKt/V (r=0.654). Average absolute error of the rate equation in predicting eKt/V was 0.118+/-0.114 (median 0.095) Kt/V units and 8.53%+/-8.36% (median 6.29%), while for the Smye method it was significantly higher [0.221+/-0.180 (median 0.190) Kt/V units, P=0.001; 16.49%+/-15.98% (median 11.88%) P=0.004]. High correlation between eKt/V and results from the rate equation indicates that urea rebound (expressed as delta Kt/V) is a function of the rate of dialysis (K/V). To test this, we analyzed the relationship of K/V and other parameters (session duration, body mass index, ultrafiltration rate, blood flow, and urea distribution volume) with delta Kt/V. The only significant (P<0.01) and highest correlation (r=0.442) was found for K/V. We conclude that in children on chronic HD, the rate equation is a better predictor of eKt/V than the Smye method, and that HD efficiency is the strongest determinant of postdialysis urea rebound in children.

[The captopril test--an aid in the detection of scarring nephropathy as a cause of arterial hypertension in children]. / Kaptoprilski test--pomoc u otkrevanju oziljene nefropatije kao uzroka arterijske hipertenzije kod dece.

Renal scarring with and without vesicoureteral reflux (VUR) has been now recognized as an important cause of paediatric hypertension for many years [1-5]. However, its pathogenesis has still remained uncleared. The widespread concept implicated the activation of renin-angiotensin system finding a powerfull support in higher peripheral plasma renin activity (PRA) in children with reflux nephropathy than in controls [6, 7] and in beneficial antihypertensive effects of ACE inhibitors. The latter, in form of captopril, has also been used in captopril test and in renal scintigraphy and isotope renography following the administration of captopril to provide evidence for renin dependent hypertension [8, 9]. Published studies of captopril test have centred on the identification of renovascular as opposed to essential hypertension [10-18, 20-22]. The aim of our study was to assess the usefulness of captopril test in differentiation between hypertensive children with renal scarring from those with essential hypertension. We studied blood pressure (BP) and PRA responses to a single dose of captopril in two groups of hypertensive children. Group A consisted of 29 patients, 14 boys and 15 girls, who had renal scaring as demonstrated by renal 99mTc dimercaptosuccinid acid scan (99m Tc DMSA) and/or intravenous pyelography. Group B included 19 patients, 19 boys and 10 girls who had arterial hypertension, while clinical examination excluded renal and other definable causes of BP elevation, and they were therefore considered to have essential hypertension. At the time of the study all patients had normal glomerular filtration rate and were not salt depleted. They did not receive any antihypertensive medication for at least two weeks. The test was performed in the morning in fasting sitting patients. At the start of the test a small vein in the hand or forearm was cannulated to permit blood sampling. BP was measured 10, 20, and 30 minutes before captopril administration to get baseline BP (mean of these three measurements) and to allow the children to become accustomed to the test procedure. A single oral dose of captopril 0.64 +/- 0.04 mg/kg body weight was given to patients from group A and almost the same dose of captopril, 0.63 +/- 0.05 mg/kg body weight, to patients from group B. The patients remained sitting and BP was measured every 15 minutes during an hour. Blood for PRA was drown in the sitting position (17 patients from group A and 16 patients from group B) before and one hour after the dose of captopril. Samples of blood for basal PRA were collected from 16 patients from group A and in 14 patients from in B in lying position after waking up in the morning. PRA was measured by radioimmunoassay using a commercially available kit, SB-REN 2, from CIS Bio International. According to the criteria of Muller et al. [10] the captopril test was positive if the post-captopril PRA (ng/ml/h) was greater than or equal to 12 with an increase of greater than or equal to 10 and relative increase of greater than or equal to 15% (400% if initial PRA was < 3). The results of our study are presented in Tables 1 and 2 and in Graphs 1 and 2. The age of patients, doses of captopril, initial BP and PRA before the use of captopril did not much differ between studied groups. Fall of BP and PRA increase were highly significant (p < 0.001) both in group A and group B. However, the hypotensive reaction of diastolic BP and MAP were more pronounced in group A (14.45 +/- 1.67% and 15.81 +/- 1.62%) than in group B (6.95 +/- 2.21% and 8.96 +/- 1.75%; p < 0.01), but there were no significant differences in PRA and systolic BP changes and positive results of captopril test between the studied groups. Hypotensive responses of diastolic BP and MAP greater than 10% of initial values were found to be more frequent in group A (79.32% and 79.31%) than in group B (26.61% and 31.57 degrees %; p < 0.001 and p < 0.01). Diastolic BP and MAP were directly related to the dose of cap