Correction: C-Peptide and leptin system in dichorionic, small and appropriate for gestational age twins-possible link to metabolic programming?

The original version of this Article was updated shortly after publication to correct two mistakes.Under Figure 2, "The results were recalculated accordingly: nanograms [ng] of studied protein per 100 µ" should read "The results were recalculated accordingly: picograms [pg] of studied protein per 100 µg".

C-Peptide and leptin system in dichorionic, small and appropriate for gestational age twins-possible link to metabolic programming?

Children born small for gestational age (SGA) are at increased risk of future glucose intolerance and type 2 diabetes, possibly after due intrauterine metabolic programming. Soluble leptin receptor (SLR) limits leptin access to signal-transducing membrane receptors. The present study examines whether SGA and appropriate for gestational age (AGA) twins differ with regard to their C-peptide, glucose and leptin systems. The markers C-peptide, glucose, fetal leptin, and SLR in cord blood were assessed in children from dichorionic twin pregnancies at delivery. In 32 cases, weight differed by >15% between twins: one demonstrated Intrauterine Growth Retardation (IUGR) (<10th percentile-SGA), while the other did not (AGAI). The other 67 pairs presented appropriate weight for gestational age (AGAII). Placental leptin and placental leptin receptor content were also assessed. Despite the same concentrations of glucose, the SGA twins maintained a higher level of C-peptide [44.48 pmol/l vs. 20.91 pmol/l, p < 0.05] than the AGAI co-twins, higher HOMA index, calculated as [C-peptide] x [Glucose] (p = 0.045), in cord blood, and a higher level of SLR [SGA vs AGAI-mean: 28.63 ng/ml vs. 19.91 ng/ml, p < 0.01], without any differences in total leptin (p = 0.37). However, SGA placentas demonstrated higher leptin level [130.1 pg/100 g total protein vs 83.8 pg/100 g total protein, p = 0.03], without differences in placental leptin receptor (p = 0.66). SGA/IUGR twins demonstrate relative insulin resistance accompanied by decreased fetal and increased placental leptin signaling. We speculate that relative insulin resistance and changes in the leptin system might be the first evidence of processes promoting deleterious metabolic programming for post-natal life.

The role of NFκB in the three stages of pregnancy - implantation, maintenance, and labour: a review article.

The transcription factor nuclear factor kappa B (NFκB) controls the expression of over 400 genes, some of which are associated with reproductive events. During implantation, immune cells accumulate in the maternal-fetal interface; they secrete inflammatory mediators under the control of NFĸB, the level of which also rises. NFĸB is then downregulated to maintain gestation, but its level rises again before birth to manage prostaglandin, cytokine, and chemokine synthesis, and to stimulate uterine contraction. This review summarises the current state of knowledge about NFκB and its role in the molecular regulation of processes related to pregnancy development. TWEETABLE ABSTRACT: This review examines the current state of knowledge about role of NFκB in the development of pregnancy.

Two polymorphisms of the FVII gene and their impact on the risk of myocardial infarction in poles under 45 years of age.

High levels of coagulation factor VII (FVII) in plasma have been associated with the increased risk of myocardial infarction (MI) in some studies. Both environmental and genetic factors are responsible for different levels of FVII in plasma. In the FVII gene there are two common polymorphisms (-323A1/A2 and IVS7)which are related to the level of FVII. The purpose of this study was to evaluate the influence of these polymorphisms on the risk of acute myocardial infarction in Poles under 45 years of age. We performed a case-control study of 266 patients with the history of MI. All patients had the first incidence of MI before 45 years of age. The control group consisted of 137 healthy individuals older than 45 years. Carriers of the A2 allele (-32341/A2 polymorphism) have a lower risk of MI than noncarriers (OR = 0.40, 95% CI = 0.20 to 0.80). The IVS7 polymorphism was shown not to be related to MI in this study. Our findings suggest that the -323A1/A2 polymorphism of the FVII gene is related to the risk of MI in Polish individuals. We pointed that plasma cholesterol (OR = 1.11, 95% CI = 1.03 to 1.18), arterial hypertension (OR = 3.84, 95% CI = 1.99 to 7.43) and family history (OR = 2.72, 95% CI = 1.57 to 4.73) are significant predictors of acute myocardial infarction.

The conversion of thyroxine to triiodothyronine in the lung: comparison of activity of type I iodothyronine 5' deiodinase in lung cancer with peripheral lung tissues.

UNLABELLED: Triiodothyronine (T3) is the main active hormone, which is derived 20% from the thyroid gland and 80% from peripheral tissues. Thyroxin--5' deiodinases play a leading role in maintaining appropriate T3 concentrations in the different cells and organs: including the lung. The deiodinases present in pneumocytes were found to be localised in endoplasmatic reticulum. Aims of this study were: 1. To estimate activities of Type I and Type II iodothyronine 5' deiodinases (DI, DII) in two histological types of lung cancer. 2. To investigate possible differences in DI and DII activities between tumour tissue and peripheral lung tissue. 3. To study whether DI and DII activities are related to the extent of the disease process and grade of differentiation of lung cancer. MATERIAL: We studied 44 patients undergoing thoracotomy due to lung cancer. Histologically: 23 pts--squamous cell cancer, 21 pts adenocarcinoma. In all patients both tumour and peripheral lung tissue were studied. DI activity was measured in pmol 1251- released from 125 IrT3/min/mg of proteins, DII activity--in fmol 125I- released from 125IT4/hour/mg of protein. RESULTS: In most specimens DI and DII activities were observed. DI activity in specimens from lung peripheral tissue was: 3.3-58.3 pmol/min/mg of protein (mean 22.20) and in lung cancer tissue was: 2.0-44.7 pmol/min/mg of proteins (mean 13.3). DII activity in lung peripheral tissue ranged from 19 to 242 fmol/h/mg protein (mean 94.4) and in lung cancer ranged from 21 to 253 fmol/h/mg protein (mean 107.9). CONCLUSIONS: 1. Conversion of T4 to T3 occurs also in the lung. 2. The activity of DI is statistically significantly lower, in lung cancer than in peripheral lung tissue (13.3 +/- 9.5 vs 22.20 +/- 13.4 pmol/min/mg protein) respectively, p < 0.001. 3. DII activity in lung is present and similar in peripheral lung and lung cancer tissue. 4. There is a non-significant trend for correlation of DI activity and grade of differentiation (G1-G3) of tumour tissue and stage of lung cancer. Abbreviations' list: T3--triiodothyronine, T4--thyroxine, FT4--free thyroxine, rT3--revers triiodothyronine TSII--Thyroid Stimulating Hormone Type I lodothyronine 5'deiodinase = type I 5'deiodinase = 5'DI = DI Type II Iodothyronine 5'deiodinase = typeII 5'deiodinase = 5'DII = DII E.S.S.--Euthyroid Sick Syndrome, hDII = human type II iodothyronine deiodinase HDII-b, hDII-c = two novel splice variants SCC--Squamous Cell Cancer, A--adenocarcinoma, BMI--Body Mass Index BSA--Bovine Standard Albumin, DTT-1,4 Dithio-L-treitol, PTU--Propylothiouracil TCA--Tricholoroacetic Acid, TNM--Tumour Nodule Metastases (class.) G1-G3-grade of differentiation, COPD--Chronic Obstructive Pulmonary Disease.

Frequency and clinical significance of beta-subunit human chorionic gonadotropin expression in non-small cell lung cancer patients.

Human chorionic gonadotropin (HCG), a classic trophoblastic marker, has been found recently in many nontrophoblastic tumors. Previously we have found elevated serum betaHCG levels in 14% of small cell lung cancer patients. The aim of the present study was to assess the frequency and clinical significance of betaHCG expression in non-small cell lung tumors and in the sera of patients. 153 non-small cell lung cancer patients entered into this study. The control group consisted of 85 patients with benign lung diseases. Serum betaHCG elevation exceeding 5 mIU/ml was found in 3.5% of patients with benign lung diseases and in 12% of lung cancer patients (p = 0.03). Tumor analysis revealed the presence of betaHCG positivity in 28% of resected lung specimens. betaHCG positivity was found more often in adenocarcinoma than in squamous cell lung carcinoma both in tissue and in serum, the differences being not significant. Elevated serum betaHCG values were found more frequently in stage IV patients than in the remainder (p = 0.03). Response to chemotherapy (partial or minor response) was obtained more often in the patients with normal serum betaHCG than in those with serum betaHCG elevation (p = 0.03). We suppose that the ability to produce betaHCG is a rare but important biologic feature of lung carcinomas combined to some extent with chemoresistance.

[The evaluation of carcinoembryonic antigen determination in the pericardial fluid in the diagnosis of the cause of pericarditis]. / Ocena przydatnosci oznaczania antygenu rakowoplodowego w plynie osierdziowym w rozpoznawaniu przyczyn zapalenia osierdzia.

Pericardial fluid CEA level was measured with radioimmunoassay in 19 patients with large pericardial effusion of unknown origin. In 11 patients malignancy was diagnosed. In all of these patients pericardial fluid CEA levels were above 7 ng/ml (mean value 52.6 +/- 42.6 ng/ml). In 8 patients the etiology of pericarditis was non-malignant. In all of them pericardial fluid CEA levels were below 7 ng/ml (mean value 2.2 +/- 1.6 ng/ml). In 9 patients with malignant pericarditis serum CEA levels were also determined: they were found to be lower than pericardial fluid CEA values in 6 patients. It was concluded that pericardial fluid CEA elevation is a reliable criteria of neoplastic pericardial involvement.

Expression of CEA and trophoblastic cell markers by lung carcinoma in association with histological characteristics and serum marker levels.

The study of tumour markers in lung cancer has focused mainly on serum-based analysis. The controversy about carcinoembryonic antigen (CEA), pregnancy specific glycoprotein 1 (SP1) and beta human chorionic gonadotropin (betahCG) production in lung carcinoma has been reported in several studies. The aims of this study were: to explore an expression of CEA, SP1 and betahCG in various histological types of lung carcinoma with respect to the grade of differentiation; and to define the relationship between tumour marker expression and serum marker concentration. Ninety two lung tumours (75 non-small cell carcinomas (NSCLC) and 17 small cell lung carcinomas (SCLC)) entered the study. Tumour marker expression was compared with the serum levels of CEA, SP1 and betahCG in 57 patients (pts) with NSCLC and four pts with SCLC. Positive immunostaining of CEA and SP1 was observed in 87% NSCLC, and betahCG was found in 24% NSCLC. In the SCLC group positive staining showed in 29% of tumours, SP1 in 51% and betahCG in 18%. Positive CEA expression ranged from 50-100% within the carcinomatous cell population (pcp) and was more characteristic for well and moderately differentiated adenocarcinomas. This finding was in contrast to squamous cell carcinomas, where the majority of tumours expressed CEA in 1-50% pcp. A significant negative correlation was noticed for adenocarcinoma between tumour expression and grade of histological differentiation for CEA (P < 0.001) and SP1 (P = 0.023). Results were not significant for squamous carcinoma. Significant differences of serum CEA concentration were noticed between adenocarcinoma and squamous carcinoma (P = 0.003). In addition, a statistically significant relation was found between serum CEA concentration and an early (I + II) and advanced (IIIa + IIIb + IV) stage of NSCLC (P = 0.031). A significant correlation was noticed when serum CEA and tumour CEA expression was compared for NSCLC (P < 0.001), and for serum betahCG and tumour betahCG (P = 0.019).

Neuron-specific enolase in non-neoplastic lung diseases, a marker of hypoxemia?

Neuron-specific enolase (NSE) is a glycolytic enzyme localized within neuronal and neuroendocrine tissues. Serum NSE is widely used as a marker of neuroendocrine tumors. Moderate serum NSE elevation has been reported in some patients with benign lung diseases. We decided to investigate whether the elevation of serum NSE in non-neoplastic lung diseases is connected with hypoxemia and to what extent the recovery of sufficient ventilation with a respirator may influence NSE concentrations. Serum NSE was estimated by means of radioimmunoassay in 83 patients with various non-neoplastic lung diseases. Serum NSE exceeding 12.5 micrograms/L was significantly more frequent in patients with marked hypoxemia (PaO2 < 6.67 kPa; p = 0.03) than in others. The median NSE value in the group of patients without respiratory failure (Ro) was 7.2 micrograms/L (10% > 12.5 micrograms/L), in the group of patients with respiratory failure not requiring mechanical ventilation (Rf) it was 8.5 micrograms/L (24% > 12.5 micrograms/L), and in the group of patients with respiratory failure requiring mechanical ventilation (Rfv) 13.1 micrograms/L (60% > 12.5 micrograms/L). The differences between the Rfv group and the other two groups (Rf and Ro) were significant (P = 0.049 and p = 0.0004, respectively). During successful mechanical ventilation elevated serum NSE decreased to values below the cutoff in 8/10 patients. We conclude that serum NSE elevation is a frequent event in patients with terminal hypoxemia in the course of benign lung diseases. Normalization of serum NSE is observed in the majority of patients during the first week of mechanical ventilation.

The role of carcinoembryonic antigen (CEA) and neuron-specific enolase (NSE) evaluation in pericardial fluid for the recognition of malignant pericarditis.

This study was designed to assess the value of tumor marker evaluation in pericardial fluid for the recognition of malignant pericarditis. Thirty-six patients with signs and symptoms of large pericardial effusion entered the study. Pericardiocentesis with pericardial fluid drainage was performed in all of them. CEA and NSE levels were evaluated in the pericardial fluid and compared to pericardial fluid cytology. The median CEA value in malignant effusions was 80 ng/ml (range 0-305 ng/ml) and in non-malignant ones 1.26 ng/ml (range 0.2-18.4 ng/ml), p < 0.01. The sensitivity of CEA elevation above 5 ng/ml for the recognition of malignant pericarditis was 73% and the specificity was 90%. Pericardial fluid cytology was positive in 22 of 26 patients with malignant pericarditis (85%). CEA exceeding 5 ng/ml or positive cytology were seen in 96% of the patients with malignant pericarditis. The median NSE value in malignant pericardial effusions was 41.8 micrograms/l (range 2-172 micrograms/l) and in non-malignant ones 5.85 micrograms/l (range 1-83.9 micrograms/l), p < 0.3. For the differential diagnosis of large pericardial effusions we would recommend simultaneous cytologic examination of pericardial fluid and CEA assessment. NSE measurement in hemorrhagic pericardial fluid is of limited value.

Neuron-specific enolase (NSE) serum level in non small cell lung cancer--can it be an indicator of tumour chemosensitivity?

It is believed that the tissue or serum expression of neuroendocrine markers in non small cell lung cancer patients can implicate better prognosis in cases undergoing chemotherapy. The aim of the study was to assess the value of NSE serum level for anticipation of the tumor response to chemotherapy. We found elevated serum level of NSE in 34 of 60 patients (56.7%) at the time of diagnosis of inoperable non small cell lung cancer, significantly more often in those presenting stage IV of disease. In 21.7% partial response and in another 21.7% minimal regression was found after chemotherapy. Treatment results revealed no significant differences in respect to NSE serum level, however 77% of patients achieving partial response had elevated serum level of NSE.

CEA, NSE and SCC Ag in bronchial lavage in patients with lung cancer.

CEA, NSE and SCC Ag levels were measured in bronchial lavage (BL) and serum in patients with endobronchial lung cancer (LC) and in patients with nonmalignant lung diseases (NMLD). In both groups of patients 100 ml of normal saline solution was used during the lavage procedure. Tumor markers were detected using radioimmunoassay. CEA levels in BL and in serum were measured in 84 patients with LC and in 94 patients with NMLD. BL CEA levels were significantly increased in patients with LC (97.4 +/- 56.4 ng/ml) in comparison to patients with NMLD (4.2 +/- 6.3 ng/ml). Patients with LC had CEA levels in lavage fluid about 30 times higher than in serum. Significantly increased BL CEA levels in patients with LC were found in the cases with more advanced bronchoscopic tumor and in those with positive bronchial secretion cytology than in other groups of patients with LC. NSE levels were measured in BL and in serum in 21 patients with small cell lung cancer, SCC Ag levels were measured in BL and in serum in 21 patients with squamous cell carcinoma. The control group consisted of 28 patients with NMLD and 8 patients with adenocarcinoma. Determination of CEA levels in BL can be useful additional diagnostic method in patients with LC. The measurement of NSE and SCC Ag levels in BL in LC patients was considered to be not useful because of the low diagnostic sensitivity and specificity.

Trophoblastic markers and CEA in non-small cell lung cancer: the comparison studies of tumour cells expression and serum concentration.

The study was designed to explore the tumour cell expression of three markers: hCG, SP1 and CEA in lung cancer in relationship with histological type and histological differentiation of tumours as well as serum concentration of antigens. 58 primary resected lung cancers: 28 adenocarcinomas, 27 squamous cell and 3 large cell carcinomas were included. Tumours immunoreactivity of three markers was evaluated by semiquantitative analysis. Simultaneously serum tumour markers were measured in 42 patients by enzyme radioimmunoassays. CEA and SP1 expressions in lung tumours were found in a majority of carcinomas-86% and 79% respectively. Expression of tumour markers was not associated with any certain histological type of carcinoma but was more characteristic for moderately and well differentiated adenocarcinomas. hCG positive tumour staining was less frequent than CEA and SP1 (only 22% tumours) and was much less intensive (5-50% population of carcinomatous cells) in the tumours. The study showed correlation between increased serum CEA concentration and tumour expression of antigen.

The clinical value of Cyfra 21-1 estimation for lung cancer patients.

Cytokeratin-19, one of the cytoskeletal proteins, is expressed both in bronchial epithelium and in lung cancer cells. The aim of our study was to establish the value of serum cytokeratin-19 soluble fragment (Cyfra 21-1) measurement in lung cancer patients. Cyfra 21-1 levels were estimated in 35 patients (pts) with benign lung diseases and in 116 lung cancer patients: 55 pts with squamous cell lung cancer, 38 pts with small cell lung cancer and 23 pts with adenocarcinoma. The cutoff level was set at 4 ng/ml with a specificity of 94% and a sensitivity of 40%. Elevated Cyfra 21-1 values were found in 44% of squamous cell lung cancer, 39% of adenocarcinoma and 34% of small cell lung cancer pts (the difference was not significant). In squamous cell lung cancer and in adenocarcinoma elevated Cyfra 21-1 values were observed more often in patients with advanced disease than in patients with limited disease. There was no significant correlation between the initial Cyfra 21-1 level and the response to chemotherapy. Cyfra 21-1 was not a prognostic indicator, although in operable squamous cell lung cancer the proportion of survivors in the second year of observation was higher among the patients with normal preoperative Cyfra 21-1 levels.

[Value of neuron specific enolase levels and squamous cell carcinoma antigen in bronchial lavage fluid in patients with lung cancer]. / Wartosc oznaczania stezen neuroswoistej enolazy i antygenu raka plaskonablonkowego w plynie uzyskanym z plukania oskrzeli u chorych na raka pluca.

The aim of the study was to assess a value of NSE and SCC Ag level determination in bronchial lavage fluid in patients with lung cancer. It was found out that NSE levels in bronchial lavage fluid were much lower than in serum and did not differentiate patients with small cell lung cancer from patients with non small cell lung cancer and nonmalignant lung diseases. Bronchial lavage SCC Ag levels were significantly higher than serum SCC Ag levels. Although determination of SCC Ag levels in bronchial lavage was also not helpful in differential diagnosis.

[The value of determining neuron specific enolase for diagnosis of complete remission during treatment of small cell lung cancer]. / Wartosc oznaczania neuroswoistej enolazy NSE dla rozpoznania remisji calkowitej w przebiegu leczenia drobnokomórkowego raka pluca.

The aim of this study was to assess whether the lowest serum NSE obtained during treatment of small cell lung cancer patients can be helpful in the diagnosis of complete remission (CR). The material consisted of 68 patients with small cell lung cancer, treated in the Institute o Tuberculosis and Lung Diseases from 1.III.1993 to 15.II.1995. In the course of treatment CR was obtained in 13 patients, partial remission (PR) in 37 and no remission (NR) in 18. The distribution and median of the lowest NSE serum levels were the same in CR and RP patients. NSE serum levels remained above normal, that is above 12.5 ng/ml, in two CR patients and in 4 PR patients. 3 patients (2 with CR and I with PR) are still living for 26, 27 and 41 months in spite of NSE serum levels 14.3, 15.6 and 13.6 ng/ml respectively. In those patients in whom NR was obtained the lowest NSE level above 20 ng/l was connected with bad prognosis. We conclude that the estimation of the lowest NSE serum level in the course of treatment can not help to differentiate CR from PR.

[The value of measuring adenosine deaminase activity in pericardial effusion fluid for diagnosing the etiology of pericardial effusion]. / Wartosc oznaczania aktywnosci deaminazy adenozyny w plynie osierdziowym w diagnostyce etiologii wysieku osierdziowego.

The diagnosis of tuberculous pericarditis is difficult. The cultures of the pericardial fluid for M.tuberculosis are often negative. The determination of ADA activity in pleural fluid in TB patients /PTS/ is very useful. It seemed reasonable to measure ADA activity in pericardial effusion. ADA activity in pericardial fluid of 40PTS/19 women and 21 men/with large pericardial effusion of different etiologies who were treated in our institute in years 1988-1995 was investigated. The median age was 44 years. In each case the pericardiocentesis was performed. PTS were grouped as follows: group I-4 PTS with strongly suspected TB pericarditis, group II-32 PTS with malignancy and group III-4 PTS with miscellaneous diseases. In group I the mean ADA activity was 24U/I(3-60), in group II 18U/I (3-60) and in group III 18U/I (0-37) (with a cutoff value for ADA activity of 40U/I). It was definitive bacteriologic diagnosis of TB pericarditis in PTS of group I. Our observation does not confirm the earlier data about the high ADA activity in clinically suspected TB pericarditis without bacteriologic diagnosis. The value of ADA determination in pericardial fluid is its high specificity (97%) in excluding of TB etiology of pericardial effusion.

[Euthyroid sick syndrome in patients with respiratory failure]. / Euthyroid sick syndrome u chorych w stanie niewydolnosci oddechowej.

There have been report concerning decrease of thyroid gland hormones concentrations in respiratory diseases. The aim of this study was to estimate the influence of severe respiratory failure (RF) of Intensive Care Unit (ICU) patients on blood serum thyroid hormone concentration. The tests were carried out in 22 ICU- patients with partial or total RF in whom the relationship between PO2, pH, PCO2 and TT3, TT4, FT3, rT3, FT4 was tested. The obtained data indicate that: 1. In patients with RF ESS takes place, 2. ESS seems to be related to the decrease of PO2; statistically significant correlation between TT3, FT3, rT3, and PO2 exist, 3. The increase of TT3 serum concentration directly correlates with the improvement of clinical state of patients. The lowest TT3 concentrations were observed in "ante mortem" patients. This fact suggest the prognostic value of TT3, TT4 concentration measurements in patients with RF.

[Comparison of the degree of regression of small cell lung neoplasm in clinical-radiologic evaluation with levels of neuron specific enolase (NSE) in serum]. / Porównanie stopnia regresji drobnokomórkowego raka pluca w ocenie kliniczno-radiologicznej z zachowaniem sie stezen neuroswoistej enolazy (NSE) w surowicy.

NSE was estimated using Pharmacia test and radioimmunologic method in the serum of 41 SCLC patients before treatment, at the time of maximal tumor response and in some patients also during progression. The level of 12,5 ng/l was regarded as the upper limit of normal. Elevated NSE levels before treatment were found in 12 out of 20 patients with limited disease and in 19 out of 21 patients with extensive disease. Complete remission (CR) was observed only in patients with limited disease and in those in whom NSE serum level was below 50 ng/l. Elevated NSE serum levels decreased in all those in whom partial remission (PR) or CR of tumor was obtained. Decrease of elevated NSE levels was however also observed in some patients with no significant regression of tumor. The decrease of serum NSE level seemed to be a good prognostic factor even in this last group. NSE serum level increased in 7 out 10 patients where progressive disease after PR was found. In 3 patients however NSE level persisted in normal values despite progression. The significance of this fact was discussed.

[Evaluation of the value of determining levels of cytokeratin-19 fragments for diagnosis of lung cancer]. / Ocena wartosci oznaczania stezenia fragmentu cytokeratyny-19 w rozpoznawaniu raka pluca.

Cytokeratins, the intermediate filaments, are expressed by many epithelial cells. Immunohistochemistry revealed the presence of cytokeratin-19 both in bronchial epithelium and in lung cancer cells. The aim of our study was to establish the value of serum cytokeratin-19 estimation by immunoenzymatic assay (Enzymun Cyfra 21-1, Boehringer Mannheim) in the patients (pts) with lung cancer (Ic). 153 pts (104 men, 49 women, median age 50 years) entered this study. The group consisted of 37 pts with benign lung diseases (control group), 56 pts with squamous cell Ic, 37 pts with small cell Ic and 23 with adenocarcinoma. Cut off value was determined at 4 ng/ml, with 96% of specificity. Elevated cytokeratin-19 values were found in 41% of pts with lung cancer (45% of squamous cell Ic, 39% of adenocarcinoma and 35% of small cell Ic). Median cytokeratin-19 values were 2.2 ng/ml in the control group, 3.4 ng/ml in squamous cell Ic, 3.3 ng/ml adenocarcinoma and 2.9 in small cell Ic. Cytokeratin-19 elevation was observed more often in non small cell Ic pts with advanced disease, stage III--46%, stage IV--50% than in early stages (I + II)--34%. In small cell Ic pts the frequency of cytokeratin-19 elevation was 20% in limited disease versus 45% in extensive disease. We conclude that cytokeratin estimation is not valuable in the recognition of histologic type of lung cancer, although elevated levels are seen more often in squamous cell Ic. Cytokeratin-19 estimation may be also helpful in lung cancer staging.