Recurrent airway infections are common in patients with Down’s syndrome (DS). Hence, ruling out Cystic Fibrosis (CF) in these patients is often required. In the past, the value of sweat testing – the gold standard to diagnose CF – has been questioned in DS as false positive results have been reported. However, these reports are based on measurements of sweat osmolality or sodium concentrations, not chloride concentrations. This study analyses sweat secretion rate and chloride concentration in sweat samples of patients with DS in comparison to healthy controls.
We assessed sweat samples in 16 patients with DS and 16 healthy controls regarding sweat secretion rate (SSR) and sweat chloride concentration.
All measured chloride concentrations were within the normal range. The chloride concentrations were slightly, but not significantly lower in patients with DS (15,54 mmol/l (±4,47)) compared to healthy controls (18,31 mmol/l (±10,12)). While no gender gap in chloride concentration could be found, chloride concentration increased with age in both groups.
Insufficient sweat was collected in 2 females with DS (12.5% of the study group) but not in an individual of the control group. A significant lower sweat secretion rate was found in the DS group (27,6 μl/30 min (± 12,18)) compared to the control group (42,7 μl/30 min (± 21,22)). In a sub-analysis, female patients produced significantly less sweat (20,8 ± 10,6 μl/30 min) than male patients with DS (36,4 ± 7,8 μl/30 min), which accounts for the difference between patients and controls. Furthermore, while the sweating secretion rate increased with age in the control group, it did not do so in the DS group. Once again this was due to female patients with DS, who did not show a significant increase of sweat secretion rate with age.
Sweat chloride concentrations were within the normal range in patients with DS and therefore seem to be a reliable tool for testing for CF in these patients. Interestingly, we found a reduced sweat secretion rate in the DS group. Whether the last one has a functional and clinical counterpart, possibly due to a disturbed thermoregulation in DS patients, requires further investigation.
Milunsky A. Cystic fibrosis and Down's syndrome. Pediatrics. 1968;42(3):501–4. PubMed
Vetrella M, Barthelmai W, Matsuda H. Down's syndrome and cystic fibrosis. Pediatrics. 1969;43(5):905. PubMed
Farrell PM, Rosenstein BJ, White TB, Accurso FJ, Castellani C, Cutting GR, Durie PR, Legrys VA, Massie J, Parad RB, et al. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic Fibrosis Foundation consensus report. J Pediatr. 2008;153(2):S4–S14. CrossRefPubMedPubMedCentral
Geetha H, Shetty KT. Sweat osmolality in Down's syndrome and cystic fibrosis in an Indian population. Br Med J (Clin Res Ed). 1987;294(6565):156. CrossRef
Symon DN, Stewart L, Russell G. Abnormally high sweat osmolality in children with Down's syndrome. J Ment Defic Res. 1985;29(Pt 3):257–61. PubMed
Geetha H, Jayakeerthy CM. Sweat osmolality in some of the congenital diseases. Indian J Pathol Microbiol. 1993;36(4):420–4. PubMed
Chapman MJ, Donoghue EC, Saggers BA, Stern J. Parotid saliva sodium in Down's disease. J Ment Defic Res. 1967;11(3):185–93. PubMed
Gibson LE, Cooke RE. A test for concentration of electrolytes in sweat in cystic fibrosis of the pancreas utilizing pilocarpine by iontophoresis. Pediatrics. 1959;23(3):545–9. PubMed
Institute CaLS. CLSI. Sweat Testing: Sample Collection and Quantitative Chloride Analysis; Approved Guideline—Third Edition: CLSI document C34-A3; Wayne. 2009.
Rees J, Shuster S. Pubertal induction of sweat gland activity. Clin Sci (Lond). 1981;60(6):689–92. CrossRef
Sneppen SB, Main KM, Juul A, Pedersen LM, Kristensen LO, Skakkebaek NE, Feldt-Rasmussen U. Sweat secretion rates in growth hormone disorders. Clin Endocrinol. 2000;53(5):601–8. CrossRef
Castells S, Torrado C, Bastian W, Wisniewski KE. Growth hormone deficiency in Down's syndrome children. J Intellect Disabil Res. 1992;36(Pt 1):29–43. PubMed
Juul A, Hjortskov N, Jepsen LT, Nielsen B, Halkjaer-Kristensen J, Vahl N, Jorgensen JO, Christiansen JS, Skakkebaek NE. Growth hormone deficiency and hyperthermia during exercise: a controlled study of sixteen GH-deficient patients. J Clin Endocrinol Metab. 1995;80(11):3335–40. PubMed
Ooi CY, Dupuis A, Ellis L, Jarvi K, Martin S, Ray PN, Steele L, Kortan P, Gonska T, Dorfman R, et al. Does extensive genotyping and nasal potential difference testing clarify the diagnosis of cystic fibrosis among patients with single-organ manifestations of cystic fibrosis? Thorax. 2014;69(3):254–60. CrossRefPubMed
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