neurokinin-a and Carcinoid-Tumor

A 52-year-old lady presented with a history of occasional, severe abdominal cramps, postprandial diarrhoea and weight loss. After routine gastrointestinal investigations, she was diagnosed with irritable bowel syndrome. Over six months, she developed occasional facial flushing prompting assessment of neuroendocrine tumour markers. Urinary 5HIAA, 5HT, chromogranin A and neurokinin A were significantly elevated. Scans showed extensive hepatic metastases but did not show the location of a primary tumour. Somatostatin analogue therapy was commenced but despite increasing doses, symptoms increased and biomarkers rose dramatically. Interferon alpha was introduced concomitant with somatostatin analogue therapy. Biomarkers were monitored regularly. Within six months, symptoms abated and biomarkers reduced, continuing to fall over the next year, close to reference range. To manage side-effects of interferon alpha, dose was reduced from time to time. During these short periods, neurokinin A showed significant transient increases (75-150 ng/L) and carcinoid symptoms returned. For more than seven years, and with the co-operation of the patient, a balance was achieved between interferon alpha side-effects and disease control. Scans showed tumour load to be stable. The patient survived for 10 years post diagnosis. She chose to discontinue interferon alpha and received peptide receptor radiation therapy in her final year. Throughout, neurokinin A remained the most sensitive monitor of her disease progression.

Topics: Antineoplastic Agents, Hormonal; Biomarkers, Tumor; Carcinoid Tumor; Disease Progression; Drug Monitoring; Female; Humans; Interferon-alpha; Intestinal Neoplasms; Liver Neoplasms; Middle Aged; Neoplasm Staging; Neuroendocrine Tumors; Neurokinin A; Somatostatin; Yttrium Radioisotopes

Midgut carcinoid tumours are uncommon tumours with an unpredictable clinical behaviour and few useful prognostic markers. Somatostatin analogues are widely used in treatment but a survival advantage has not been proven. We analysed features associated with poor prognosis and assessed the clinical implications of the biochemical response to therapy.. Clinical and biochemical data were collected for patients with midgut carcinoid tumours attending a tertiary referral neuroendocrine clinic from 1978 to 2000. Using death as the end point, univariate and multivariate survival analyses were performed to identify prognostic indicators. The significance of altering biomarkers with therapy was also studied by including repeated measurements of the most prognostic biochemical parameter in a time dependent covariate survival analysis.. We identified 139 patients with sufficient data for our analyses. Factors associated with a poor outcome on univariate analysis included: plasma neurokinin A (NKA), urinary 5-hydroxyindolacetic acid output, age, and >/=5 liver metastases. Plasma NKA was the strongest and only independent predictor of outcome on multivariate analysis. Patients in whom NKA continued to rise despite somatostatin analogues had a significantly worse survival than those in whom NKA stabilised or fell (one year survival rate 40% v 87%). Time dependent covariate analysis concluded that survival was better predicted by the most recent plasma NKA value rather than by the initial value.. Plasma NKA is an accurate marker of prognosis for midgut carcinoid tumours. This is the first paper to support a survival advantage in patients in whom plasma NKA is altered by somatostatin analogues.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents, Hormonal; Biomarkers, Tumor; Carcinoid Tumor; Female; Humans; Hydroxyindoleacetic Acid; Intestinal Neoplasms; Male; Middle Aged; Neurokinin A; Prognosis; Retrospective Studies; Somatostatin; Survival Analysis; Treatment Outcome

Tachykinins are a family of peptides that may be present in and secreted from carcinoid tumours of mid-gut origin. They are likely to play a role in the pathogenesis of, e.g. the flush, dyspnoea and valvular heart disease seen in the carcinoid syndrome. Since tachykinins are secreted from the tumour into the circulation in bursts, coinciding with flushing attacks, and have short half-lives, we anticipated that analysis of 24-h urine excretion of immunoreactive tachykinin metabolites might prove to be a more sensitive and stable parameter for monitoring than tachykinin-like immunoreactivity in plasma. The study included 48 patients hospitalized for treatment of advanced carcinoid tumours and 32 healthy controls. The urine excretion of tachykinin-like immunoreactive metabolites in the carcinoid patients (median 27.5 pmol 24 h-1, interquartile range (IQR) 8.5-51.0 pmol 24 h-1) was significantly (p<0.001) higher than that in the 32 healthy subjects (median 3.0 pmol 24 h-1, IQR 0.9-4.20 pmol 24 h-1). Of the patients, 38 (79%) had elevated 24-h urine excretion of tachykinin-like immunoreactive metabolites while 31 (64%) had elevated plasma concentrations of tachykinin-like immunoreactive metabolites. Of the patients, 27 (56%) had elevated concentrations of tachykinin-like immunoreactive metabolites both in plasma and urine, 12 (25%) had elevated concentrations only in urine excretion, 3 (6%) had elevated concentrations of only plasma tachykinin-like immunoreactive metabolites and 7 (14%) had elevation of neither plasma nor urine concentrations. Analysis by means of different column chromatographic techniques indicated that the immunoreactive material was heterogeneous, with some components co-eluting with oxidized neurokinin A (NKA) and neuropeptide K (NPK). The urine tachykinin-like immunoreactivity correlates well with that of plasma, but is a slightly more sensitive indicator of elevated tachykinin-like immunoreactivity, probably since levels of urine tachykinin-like immunoreactive metabolites reflect the overall amount of the latter secreted into the circulation during 24 h.

Topics: Antibodies; Carcinoid Tumor; Chromatography, Gel; Chromatography, High Pressure Liquid; Eledoisin; Hydroxyindoleacetic Acid; Intestinal Neoplasms; Neurokinin A; Neurokinin B; Neuropeptides; Sulfoxides; Tachykinins; Urea

Commercial sources for neuropeptide radioimmunoassays have made this sensitive tool available to clinical investigators for monitoring the potential involvement of neuropeptides in pain modulation. We measured substance P-like immunoreactivity in the plasma, saliva, and pericardial fluid of subjects with and without pain (chronic and acute) to determine if substance P levels are altered. Some recent studies have suggested that substance P in various body fluids may be a correlate of chronic pain. To test this correlation it is important to ensure that the assay is measuring what it was designed to measure. Therefore, the influence of three tachykinins on the analysis of substance P concentrations was assessed with a commercially available radioimmunoassay kit. A small (approximately 2 to 6%), apparently nonspecific elevation in measured substance P was found when alpha-neurokinin, beta-neurokinin, or eledoisin was incubated with substance P and its antibody. Our results also indicate an apparent specific affinity of the substance P antibody for alpha-neurokinin (above 1,000 pg/ml) and beta-neurokinin (above 5,000 pg/ml). Substance P levels in the body fluids we tested ranged from 0.47 to 62.88 pg/mg protein (47.4 to 230.8 pg/ml). Levels of the tested tachykinins have not been determined in body fluids. If alpha-neurokinin or beta-neurokinin is found to be present in high concentrations in these fluids, this commercially available substance P kit may overestimate substance P levels. The concentrations of tachykinins necessary to interfere specifically with the assay are 10- to 100-fold higher than substance P in body fluids.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Angina Pectoris; Back Pain; Carcinoid Tumor; Eledoisin; Humans; Neurokinin A; Neurokinin B; Pericardial Effusion; Protein Binding; Saliva; Species Specificity; Substance P

Cutaneous flushing was provoked in seven patients with metastatic carcinoid tumours and the carcinoid syndrome by an intravenous injection of pentagastrin (0.6 micrograms.kg-1 body weight). The patients were studied before and 1 h after a subcutaneous injection of the long-acting somatostatin analogue octreotide 50 micrograms (Sandostatin). The severity of the carcinoid flush in all the patients was reduced by administration of the analogue. The rise in facial temperature was 1.3 (0.3) degree C before and 0.8 (0.2) degree C after octreotide. Six patients responded to pentagastrin with a rise in the circulating neurokinin A-like immunoreactivity (NKA-LI) and five patients with a rise in circulating substance P-like immunoreactivity (SP-LI). No cutaneous flushing or rise in tachykinin concentration was observed in healthy subjects (n = 6) after injection of pentagastrin. The rise in NKA-LI in the patients was decreased by 61 (14)% and the rise in SP-LI by 54 (13)% after octreotide. Although flushing still occurred, the tachykinin response in two patients was completely abolished. The data demonstrate that the release of tachykinins from carcinoid tumours during pentagastrin-induced flushing is subject to partial inhibition by octreotide. However, the occurrence of a flush in some patients in the absence of a detectable rise in circulating tachykinins indicates that the latter peptides cannot be the sole causative agent of the carcinoid flush.

Topics: Aged; Body Temperature; Carcinoid Tumor; Female; Flushing; Humans; Ileal Neoplasms; Liver Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Neurokinin A; Octreotide; Pentagastrin; Radioimmunoassay; Substance P; Tachykinins

Antisera of defined regional specificity have been used to measure the concentration of substance P-like immunoreactivity (SP-LI) and neurokinin A-like immunoreactivity (NKA-LI) during a meal-induced flush in 10 patients with metastatic carcinoid tumours. Although all patients flushed, NKA-LI levels in five patients and SP-LI in six patients were not elevated relative to healthy subjects (NKA-LI, less than 3 pg/ml; SP-LI, less than 10 pg/ml) both in the fasted state and after food. In the patients with elevated basal plasma tachykinin levels, increases in NKA-LI and SP-LI after food were erratic and did not correspond to a defined digestive phase or the occurrence of the flush. Chromatographic analysis of plasma demonstrated the presence of neuropeptide K and neurokinin A, and the detection of COOH-terminal fragments of substance P is consistent with the higher levels of circulating SP-LI measured with a COOH-terminally directed antiserum compared with an NH2-terminally directed antiserum. Subcutaneous injection of the somatostatin analogue SMS 201-995 (50 micrograms) alleviated symptoms of flush in two of three patients but only partially suppressed NKA-LI and SP-LI concentrations. It is concluded that circulating tachykinins cannot be solely responsible for the meal-induced carcinoid flush.

Topics: Adult; Carcinoid Tumor; Female; Food; Humans; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Neurokinin A; Neuropeptides; Octreotide; Peptides; Somatostatin; Tachykinins

A metastasis to the right liver lobe of an argyrophil/argentaffin midgut carcinoid tumour in a patient with the classical carcinoid syndrome was examined for the presence of tachykinins other than substance P, using a specific antiserum. The extract was initially purified using SepPak cartridges, and subsequently subjected to cation-exchange chromatography on SP Sephadex C-25 which separated the immunoreactive material into two main components (components I and II). Both were further purified by anion-exchange chromatography on DEAE-Sephadex A-25, and by reverse-phase fast protein liquid chromatography. Component II was identified as neurokinin A by its immunochemical and chromatographic properties and amino acid sequence analysis. Component I consisted of two molecular forms which were identified as neurokinin A(3-10) and neurokinin A(4-10) by amino acid sequence analysis. The tumour tissue contained only small amounts of the eledoisin-like peptide that has earlier been demonstrated in mammalian tissues. Although this component behaved like the nonmammalian peptide eledoisin on reverse-phase HPLC and on reverse-phase ion-pair chromatography, eledoisin-specific antiserum E2 indicated that eledoisin-like peptide is not identical to eledoisin. Neurokinin A in carcinoid tumours has an N-terminal heterogeneity; this multiplicity constitutes a further support for the hypothesis that carcinoid tumours produce a number of tachykinins which may be present in different relative amounts in individual patients and may contribute to the individual differences in symptomatology.

Topics: Carcinoid Tumor; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Humans; Ileal Neoplasms; Liver Neoplasms; Neurokinin A; Neuropeptides; Peptide Fragments; Radioimmunoassay; Solubility; Water

An antiserum raised against neurokinin A has been used to demonstrate storage and release of neurokinin A-like immunoreactivity by carcinoid tumours. The antiserum showed reactivity towards members of the tachykinin family of polypeptides in the order: neurokinin A greater than eledoisin greater than neurokinin B greater than kassinin greater than substance P greater than physalaemin but the magnitude of the cross-reactivity with substance P and physalaemin was less than 1% of that of neurokinin A. A sensitive (IC50 238 fmol/ml; minimum detectable concentration, 9 fmol/ml) radioimmunoassay was set up using this antiserum. Extracts of metastatic tumour tissue from four patients with a primary carcinoid tumour in the midgut contained both neurokinin A-like immunoreactivity (NKA-LI) and substance P-like immunoreactivity (SP-LI). The concentrations (pmol/g wet weight) of NKA-LI and SP-LI in the tumours were: patient A 210, 201; patient B 2276, 6849; patient C 1198, 834 and patient D 424, 379. Analysis of the tumour extracts by reverse phase HPLC indicated that the NKA-LI was heterogeneous. Under two different conditions of chromatography, one component was eluted with the same retention time as neurokinin A. Two further components were more hydrophobic than neurokinin A but were not eluted with the retention time of neurokinin B. Analysis of these components by gel filtration indicated a molecular weight in the 3000-4000 range suggesting that they may be related to neuropeptide K, an N-terminally extended form of neurokinin A. NKA-LI and SP-LI were undetectable in the plasma of patients A and D but were elevated in patient B (NKA-LI 1005 +/- 114; SP-LI 345 +/- 85 fmol/ml) and patient C (NKA-LI 80 +/- 31; SP-LI 21 +/- 13 fmol/ml).

Topics: Carcinoid Tumor; Chromatography, Gel; Chromatography, High Pressure Liquid; Female; Humans; Male; Middle Aged; Nerve Tissue Proteins; Neurokinin A; Protein Conformation; Radioimmunoassay; Time Factors

Evidence is presented for the presence of an entire family of tachykinin-immunoreactive peptides in plasma and tumor tissues from patients with carcinoid tumors. The peptides include in addition to substance P and neurokinin A; neurokinin B, an eledoisin like peptide and neuropeptide K--a 36 amino acid long tachykinin which contains neurokinin A at its C-terminus. Neuropeptide K seems to be the tachykinin which is present in highest concentrations in plasma as well as in acetic acid extracts of tumor tissues. It is highly biologically active, and may therefore contribute to the clinical symptoms of carcinoid tumors.

Topics: Carcinoid Tumor; Chromatography, High Pressure Liquid; Chromatography, Ion Exchange; Eledoisin; Humans; Immunoassay; Nerve Tissue Proteins; Neurokinin A; Neurokinin B; Oligopeptides; Substance P; Tachykinins

Using an antiserum directed at the COOH-terminus of tachykinins, we have examined postmortem tissue from two cases of metastatic ileal carcinoid for the presence of tachykinin-like immunoreactivity. The vast majority of the immunoreactive tachykinin-like material eluted from a Sephadex G-50 column as two peaks at positions corresponding to molecular weights of 1300 and 850. The 1300 dalton peak was resolved by reverse-phase-HPLC into two components which by Edman sequencing, amino acid analysis, and fast atom bombardment (FAB)-mass spectrometry criteria, were identified as substance P and substance K. The 850 dalton peak was also resolved on RP-HPLC into two peaks which were resistant to Edman degradation but from amino acid analysis and FAB-mass spectrometry criteria were identified as pyro-Glu-substance P 5-11 and oxidized pyro-Glu-substance P 5-11. In control experiments substance P 5-11 was converted to pyro-Glu-substance P 5-11 during the extraction procedure. Both tumors also contained a minor immunoreactive peak which eluted from a Sephadex G-50 sizing column at a position corresponding to a molecular weight of 4000 which probably represents neuropeptide K. These results suggest that beta-preprotachykinin is preferentially expressed in carcinoid tumors and that substance K may also play a role in the carcinoid syndrome.

Topics: Amino Acid Sequence; Carcinoid Tumor; Chromatography, High Pressure Liquid; Humans; Ileal Neoplasms; Mass Spectrometry; Neoplasm Metastasis; Nerve Tissue Proteins; Neurokinin A; Peptide Fragments; Substance P; Tachykinins