Hyposecretion of beta-adrenergically induced sweating in cystic fibrosis heterozygotes

In order to determine if expression of the cystic fibrosis gene can be detected in heterozygotes, we determined sweat responses induced by local stimulation with cholinergic and beta-adrenergic agents for 20 heterozygotes, 19 age- and sex-matched controls, and five subjects with cystic fibrosis. Active sweat glands were counted and sweat droplets were collected in constant bore capillaries and measured optically. Each subject was tested two to six times. The central finding was that the sweat response of carriers was significantly lower than controls to beta-adrenergic stimulation (p = 0.0013, two-tailed t test; p less than 0.02, Mann-Whitney U), while cystic fibrosis homozygotes did not sweat at all. In contrast, the cholinergic sweat responses did not differ between carriers and controls. For both groups the correlation between cholinergic and beta-adrenergic sweating was positive, but a linear regression of beta-adrenergic sweat responses as a function of cholinergic sweat responses yielded slopes that were significantly different for the two groups. The ratio of beta-adrenergic to cholinergic sweating was plotted for each subject; the mean ratio of the carriers was approximately half of the mean for the controls (p = 0.0002 using t test or p less than 0.002 using the Mann-Whitney U). Our results confirm previous studies and provide new evidence that carriers have, on average, a beta-adrenergically stimulated secretory response that is significantly reduced relative to the control response.     

Altered intracellular calcium in fibroblasts from patients with cystic fibrosis and heterozygotes.

The importance of intracellular calcium (Ca) in secretion and transmembrane ion movement led us to study Ca in cells from patients with cystic fibrosis (CF) which is a lethal genetic exocrinopathy. Skin fibroblasts from patients with CF, obligate heterozygotes (HZ), and age- and sex-matched controls (C) were used in matched pair experiments measuring 45Ca exchange into and efflux from the cells over time. CF cell lines and HZ cell lines exhibit increased 45Ca exchange when compared with their respective controls (P less than 0.005). The magnitude of this difference (approximately 30%) is not reduced when cells are washed with lanthanum chloride after the exchange period. This difference is likely attributable to an altered capacity of one or more of the intracellular Ca sequestering organelles. Further evidence for this explanation was seen in 45Ca efflux experiments in which CF cells retained a higher percent of their initial 0-time 45Ca than did C cells late in the efflux period (P less than 0.05). The finding of an altered Ca pool size in both CF and particularly HZ cells suggests that altered Ca metabolism is related to the basic gene defect in CF.     

Distribution of serum amylase isoenzymes in cystic fibrosis homozygotes and heterozygotes

A simple method has been elaborated for the routine separation and quantitative determination of amylase isoenzymes. The ratio P/S, the quotient of the activity values obtained by densitometric evaluation of the pancreatic and salivary isoenzymes, is used to characterize their distribution. In healthy adults and children the value for P/S is above 1 in 80% of the cases, with a mean of 1.87 +/- 0.23. In 90% of heterozygote CF gene-carriers, the P/S is below 1 with a mean of 0.68 +/- 0.13. In addition to the higher total amylase activity, in MV homozygote patients P/S is less than 0.1, and even 0.001. The phenomenon is explained by a compensatory enhancement of salivary activity. The method is a suitable diagnostic test of the exocrine function of the pancreas and for evaluation of the serum amylase isoenzymes. The P/S value allows to differentiate heterozygote CF gene-carriers from homozygotes and healthy individuals.     

Chloride and sodium ion concentrations in saliva and sweat as a method to diagnose cystic fibrosis

ObjectiveCystic fibrosis diagnosis is dependent on the chloride ion concentration in the sweat test (≥ 60 mEq/mL – recognized as the gold standard indicator for cystic fibrosis diagnosis). Moreover, the salivary glands express the CFTR protein in the same manner as sweat glands. Given this context, the objective was to verify the correlation of saliva chloride concentration and sweat chloride concentration, and between saliva sodium concentration and sweat sodium concentration, in patients with cystic fibrosis and healthy control subjects, as a tool for cystic fibrosis diagnosis.MethodsThere were 160 subjects enrolled: 57/160 (35.70%) patients with cystic fibrosis and two known CFTR mutations and 103/160 (64.40%) healthy controls subjects. Saliva ion concentration was analyzed by ABL 835 Radiometer^® equipment and, sweat chloride concentration and sweat sodium concentration, respectively, by manual titration using the mercurimetric procedure of Schales & Schales and flame photometry. Statistical analysis was performed by the chi-squared test, the Mann–Whitney test, and Spearman's correlation. Alpha = 0.05.ResultsPatients with cystic fibrosis showed higher values of sweat chloride concentration, sweat sodium concentration, saliva chloride concentration, and saliva sodium concentration than healthy controls subjects (p-value < 0.001). The correlation between saliva chloride concentration and sweat chloride concentration showed a positive Spearman's Rho (correlation coefficient) = 0.475 (95% CI = 0.346 to 0.587). Also, the correlation between saliva sodium concentration and sweat sodium concentration showed a positive Spearman's Rho = 0.306 (95% CI = 0.158 to 0.440).ConclusionsSaliva chloride concentration and saliva sodium concentration are candidates to be used in cystic fibrosis diagnosis, mainly in cases where it is difficult to achieve the correct sweat amount, and/or CFTR mutation screening is difficult, and/or reference methods for sweat test are unavailable to implement or are not easily accessible by the general population.     

Serum pancreatic enzyme levels in cystic fibrosis heterozygotes after secretin and cholecystokinin infusion

ABSTRACT. The response of serum trypsinogen and amylase to pancreatic stimulation was examined in heterozygotes for cystic fibrosis (CF) and normal subjects. Serum trypsinogen rose significantly from the baseline in CF heterozygotes at 30 (p<0.001), 60 (p<0.01) and 120 minutes (p<0.05), but at only 30 minutes (p<0.02) in normal subjects. The mean serum trypsinogen level at 30 and 60 minutes was significantly higher in CF heterozygotes than normal subjects (both p<0.05). There was no change in total serum α-amylase levels.
These results suggest that CF heterozygotes show either partially obstructed pancreatic ducts or pancreatic acini which secrete trypsinogen at an increased rate when stimulated.     

Demonstration of human leukocyte degranulation induced by sera from homozygotes and heterozygotes for cystic fibrosis.

The ability of epsilon-amino caproic acid (EACA)-treated normal serum and of cystic fibrosis (CF)-affected and carrier sera to promote the release of lysosomal enzymes from sensitized human polymorphonuclear leukocytes (PMN) was assessed through the measurement of beta-glucuronidase and myeloperoxidase activity after exposure of these cells to the various test sera. This study was initiated to extend the analogies between preciliary dyskinesia factor (pre-CDF), separated from the cell-free media of cultures derived from CF homozygous and heterozygous individuals, and C3a anaphylatoxin. The extent of lysosomal degranulation of human PMN exposed to fresh untreated sera of each of five controls, seven CF homozygotes, and eight heterozygotes, as expressed by the amount of beta-glucuronidase releases, was 7.84% (+/- 0.934) for countrol sera, 14.01% (+/- 1.79) for CF-affected sera, and 10.61% (+/- 1.43) for heterozygous sera. The difference between CF homozygotes and control subjects is significatn (P less than 0.0001), as is the difference between CF-affected and carrier individuals (0.001 less than P less than 0.005) and between control subjects and carriers (0.001 less than P less than 0.005), when beta-glucuronidase. However, the differences between control subjects and CF heterozygous individuals are not significant. Treatment of these sera with 1 M EACA gave values for beta-glucuronidase and myeloperoxidase release which are slightly reduced when compared with those obtained with fresh, untreated samples. EACA apparently reduces the activity of beta-glucuronidase released from PMN. Amicon filtration studies of these serum samples demonstrated that degranulating ability and the presence of cilicary dyskinesia, as assessed by rabbit tracheal bioassay, are not always associated. Therefore, the relationship between pre-CDF and the degranulator activity in native CF-affected and carrier sera is unclear, in part because of the limitations inherent in the test systems employed.     

Decreased renal clearance of sodium in cystic fibrosis

In 10 patients with cystic fibrosis (CF) and 10 controls of similar age quantitative segmental handling of sodium was estimated by lithium clearance. In the CF group, there was a tendency for an increased glomerular filtration rate (GFR) and increased absolute proximal sodium reabsorption. The fractional distal sodium reabsorption was significantly (p = 0.015) increased and sodium clearance was significantly (p less than 0.01) decreased in CF.     

C reactive protein concentrations in cystic fibrosis.

Serum concentrations of C reactive protein were measured in a cross sectional study of 36 patients with cystic fibrosis and correlated with clinical and radiological assessments. C reactive protein concentration was highly correlated with the Shwachman clinical evaluation score, forced vital capacity as a percentage of the predicted value, and the Chrispin-Norman x ray score. C reactive protein may be a useful objective index of severity of disease in patients with cystic fibrosis.     

Sputum tumour necrosis factor-alpha and leukotriene concentrations in cystic fibrosis

It is postulated that a vigorous host inflammatory response in the cystic fibrosis lung contributes to lung injury. Tumour necrosis factor-alpha (TNF-alpha) may play a part in that process and in the generation of leukotrienes. Therefore, the relationships between sputum TNF-alpha, leukotriene concentration, and lung function abnormalities in 16 children with cystic fibrosis were investigated. Each subject provided sputum samples and performed spirometry. TNF-alpha was measured by enzyme linked immunosorbent assay; individual leukotrienes were separated using high performance liquid chromatography and quantified by radioimmunoassay. The geometric mean concentration of TNF-alpha was 129.7 pg/ml and 95% confidence interval 48.2 to 348.3. Mean (SEM) leukotriene B4 (LTB4) was 97.8 (22.9) pmol/g and total cysteinyl leukotrienes were 60.9 (14.8) pmol/g. Mean (SD) forced expiratory volume in one second (FEV1) of the group was 53 (15)% of predicted and forced vital capacity (FVC) was 65 (14)% of predicted. There was a significant positive correlation between TNF-alpha and both LTB4 and the total cysteinyl leukotriene sputum content. An inverse relationship existed between TNF-alpha and FEV1 and FVC. Moreover, a negative correlation was observed between sputum LTB4 and FEV1 and FVC. These results suggest that TNF-alpha and the leukotrienes may participate in the airways inflammation and airflow obstruction observed in cystic fibrosis subjects and support the hypothesis that TNF-alpha upregulates the 5-lipoxygenase pathway in vivo.     

Plasma vitamin K1 concentrations in cystic fibrosis.

Plasma concentrations of vitamin K1 were similar in 37 patients with cystic fibrosis (median 46 ng/l) and 16 controls (49 ng/l). The plasma concentrations were lower than those previously described in adults, but higher than in neonates. There was no association between an increase in prothrombin time and vitamin K1 plasma concentration.     

Diminished concentrations of insulin-like growth factor I in cystic fibrosis

Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data on IGF-I in cystic fibrosis are sparse and conflicting. From 1990-3, 235 of our 240 patients (114 males, 121 females, median age 16.2 years, ranged 0.1-44.0 years) had IGF-I measured once by radioimmunoassay. IGF-I was significantly reduced compared with a healthy Scandinavian control population: mean (-2 SD to +2 SD) IGF-I SD score was -0.97 (-3.7 to 1.7) in males and -0.67 (-3.2 to 1.9) in females. Height SD score was -0.95 (-3.3 to 1.4) in males and -0.81 (-3.2 to 1.6) in females. In patients who were still in the growth period a significant correlation of IGF-I SD score to height SD score (r = 0.28, p < 0.001) was found. The low IGF-I concentrations may reflect the catabolic state of many patients with cystic fibrosis and play a part in their abnormal growth pattern.     

beta-adrenergic sweat responses in cystic fibrosis heterozygotes with and without the delta F508 allele.

Cystic fibrosis (CF) causes early death for most homozygotes, yet has a carrier frequency among Caucasians of about 4-5%, suggesting a heterozygote advantage. The major defect in the CF gene is a three-base deletion leading to loss of a phenylalanine residue at position 508 (delta F508) that accounts for about 68% of CF alleles in the North American population; the remaining 32% appears to consist of a large assortment of mutations. Sweat secretion in response to beta-adrenergic stimulation is completely lacking in CF homozygotes and is reduced to 1/2 normal in heterozygotes. To determine if this secretory process is affected by different CF alleles, we used the polymerase chain reaction technique with DNA obtained from peripheral leukocytes to determine retrospectively the presence or absence of the delta F508 allele in 20 CF heterozygotes for whom sweat responses to beta-adrenergic stimulation had previously been determined. Twelve of 20 subjects (60%) were positive for the delta F508 mutation. The variance in sweat responses was not reduced in the delta F508 group relative to the non-delta F508 group, but a gender/allele interaction was noted.     

Viscosity and electrolyte concentrations in gastric juice from cystic fibrosis children compared to healthy children

The viscosity of gastric juice and the concentrations of sodium, potassium, calcium, magnesium and chloride ions were measured before and after stimulation with pentagastrin in 10 children with cystic fibrosis and compared to those in 10 healthy children of corresponding ages. The viscosity values followed the same patterns as those for the sodium and calcium ion concentrations and were higher in the cystic fibrosis group. The electrolyte concentrations in the basal and different post-stimulation fractions of the gastric juice were higher in the cystic fibrosis group. Significant differences between both groups could only be found in the electrolyte concentrations. The total secretion of each of the electrolytes was the same in both groups because along with the increased electrolyte concentration in the cystic fibrosis group there was a reduced volume of gastric juice. The dependence of viscosity on the individual electrolyte concentration is discussed. The differences in the viscosity and the electrolyte concentrations in gastric juice from the cystic fibrosis children seems to be due to changes in the process of gastric secretion and not due to the influence of swallowed saliva.This publication includes parts of the dissertation thesis of the physician Mr. Klaus Dieter Schmidt. Unfortunately, due to his death, he could not formally be awarded his doctoral title     

Edetate sodium aerosol in Pseudomonas lung infection in cystic fibrosis

In vitro and animal experimental data suggest the combination of edetate sodium (EDTA) by aerosol plus oral antimicrobials might be effective in the treatment of chronic Pseudomonas infection in patients with cystic fibrosis (CF). For six months we studied the effects of edetate sodium administered by ultrasonic nebulizer to ten children with CF and chronic Pseudomonas aeruginosa infection in a double-blind, placebo-controlled, crossover study. The children had evidence of mild to moderate disease at entry in the study, with a mean (+/- SD) forced expiratory volume in the first second of 85% (+/- 18%) of the predicted value and a mean (+/- SD) Shwachman-Kulczycki score of 83 (+/- 7)/100. Each child was on a three-month regimen of aerosolized edetate sodium plus oral tetracycline twice daily followed by three months of placebo aerosol plus tetracycline or vice versa. Progress was assessed by measurement of pulmonary function, physical examination, and sputum cultures at four weekly intervals, plus chest roentgenograms on entry and after each of the three-month treatment periods. Daily symptoms were assessed using a diary card system. Two patients could not complete the study, one because of severe respiratory relapse, the other because of antibiotic side effects. Of the remaining eight patients, none showed any improvement in pulmonary function, weight gain, or growth acceleration, and none was rendered free of Pseudomonas lung infection. Daily symptom scores and chest roentgenograms were unaltered by edetate sodium. We conclude that the combination of aerosol edetate sodium plus oral tetracycline over a three-month period does not modify the clinical course nor the pulmonary flora in patients with CF with chronic Pseudomonas lung infection.     

Faecal interleukin-8 and tumour necrosis factor-alpha concentrations in cystic fibrosis

Interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) concentrations were measured in faecal samples from nine patients with cystic fibrosis and nine healthy age matched controls. The patients were assessed with Shwachman score, apparent energy absorption, pancreatic enzyme dosage, simple spirometry, and presence of pseudomonal colonisation. Median (range) wet stool IL-8 and TNF-alpha concentrations in patients were 32,113 pg/g (21,656-178,128) and 3187 pg/g (368-17,611) respectively, compared with < 43.5 pg (IL-8)/g (< 22-4079) and 99 pg (TNF-alpha)/g (< 0.26-231) in controls. IL-8 concentration was negatively correlated with Shwachman score (r = -0.79) and pancreatic enzyme dosage (r = -0.77), but not with energy absorption. Seven patients were mature enough to cooperate with spirometry. Their IL-8 concentrations correlated with percentage predicted forced expiratory volume in one second (r = -0.78). IL-8 concentration was greater in four patients with, than five without, established pseudomonal colonisation: median difference 134,583 pg/g. TNF-alpha concentration was not correlated with measures of disease severity. Faecal IL-8 concentration might reflect the severity of pulmonary inflammation in cystic fibrosis and could provide an easily obtainable marker of disease activity.     

Diminished concentrations of insulin-like growth factor I in cystic fibrosis.

Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data on IGF-I in cystic fibrosis are sparse and conflicting. From 1990-3, 235 of our 240 patients (114 males, 121 females, median age 16.2 years, ranged 0.1-44.0 years) had IGF-I measured once by radioimmunoassay. IGF-I was significantly reduced compared with a healthy Scandinavian control population: mean (-2 SD to +2 SD) IGF-I SD score was -0.97 (-3.7 to 1.7) in males and -0.67 (-3.2 to 1.9) in females. Height SD score was -0.95 (-3.3 to 1.4) in males and -0.81 (-3.2 to 1.6) in females. In patients who were still in the growth period a significant correlation of IGF-I SD score to height SD score (r = 0.28, p < 0.001) was found. The low IGF-I concentrations may reflect the catabolic state of many patients with cystic fibrosis and play a part in their abnormal growth pattern.     

Faecal interleukin-8 and tumour necrosis factor-alpha concentrations in cystic fibrosis.

Interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) concentrations were measured in faecal samples from nine patients with cystic fibrosis and nine healthy age matched controls. The patients were assessed with Shwachman score, apparent energy absorption, pancreatic enzyme dosage, simple spirometry, and presence of pseudomonal colonisation. Median (range) wet stool IL-8 and TNF-alpha concentrations in patients were 32,113 pg/g (21,656-178,128) and 3187 pg/g (368-17,611) respectively, compared with < 43.5 pg (IL-8)/g (< 22-4079) and 99 pg (TNF-alpha)/g (< 0.26-231) in controls. IL-8 concentration was negatively correlated with Shwachman score (r = -0.79) and pancreatic enzyme dosage (r = -0.77), but not with energy absorption. Seven patients were mature enough to cooperate with spirometry. Their IL-8 concentrations correlated with percentage predicted forced expiratory volume in one second (r = -0.78). IL-8 concentration was greater in four patients with, than five without, established pseudomonal colonisation: median difference 134,583 pg/g. TNF-alpha concentration was not correlated with measures of disease severity. Faecal IL-8 concentration might reflect the severity of pulmonary inflammation in cystic fibrosis and could provide an easily obtainable marker of disease activity.     

Effect of saliva from cystic fibrosis patients and from normal subjects on red blood cell sodium transport

Saliva, whether taken from patients with cystic fibrosis or from normal subjects, caused an increase in red blood cell Na+ efflux (in the presence or absence of ouabain) of 19-29% as compared with non-saliva controls. However, there was no significant difference between the effects of cystic fibrosis saliva and normal saliva.