D-Lactate


Indications:

The presence of D-Lactate (D-lactic acid) in the blood is a reflection of bacterial overgrowth in the gastro-intestinal tract. Raised D-lactate is a rare finding in humans, but a common problem among ruminants (veterinary surgeons recognise that D-lactate production in cows is potentially fatal). D-lactic acidosis in the human as first described in association with short bowel syndrome (post-operative bacterial overgrowth) [1].

D-lactate should not be confused with L-lactate, which is a normal product of anaerobic metabolism. Unlike the L-form, D-lactate is not metabolised by mammals and its elimination from the body depends mainly on renal excretion.

Patient Instructions:

No special preparation required.

Appointment Notes:

Samples have to be separated and frozen immediately after collection

Clinical Indications:

D-lactate is produced from non-absorbed carbohydrates by colonic bacteria (which may also proliferate in the ileum). The absorption of large amounts of D-lactate can cause metabolic acidosis, altered mental status and a variety of other neurologic symptoms, in particular dysarthria and ataxia [2,3,4]. Its measurement is part of the differential diagnosis of chronic fatigue syndrome [5]. Although a temporal relationship has been described between elevations of plasma D-lactate and the accompanying encephalopathy, the exact neurological mechanisms remain undescribed [6].

Otherwise healthy children with gastroenteritis may also develop D-lactic acidosis.

There are a number of other tests of gastro-intestinal function available from Biolab the gut fermentation test, the PEG profile (gut permeability), the measurement of plasma short-chain polypeptides and the lactulose breath hydrogen test. Each of these tests provides somewhat different information from the D-lactate test, which is specific for the presence of D-lactate-producing bacteria in the gut (probably Enterococcus and Streptococcus spp. [5]).

Unaffected subjects have plasma concentrations of D-lactate of less than 60umol/L.

Datasheet:

dlactate.pdf (Click to Download)

Sample Report:

rep-dlactate.pdf (Click to Download)

Sample Requirements:

Grey (fluoride/oxalate) tube

Postal Samples Acceptable:

Yes

References:

1. Oh MS, Phelps KR, Traube M, et al. D-Lactic acidosis in a man with the short-bowel syndrome. NEJM 1979;301:249-252

2. Dahlquist NR, Perrault J, Callaway CW, Jones JD. D-Lactic acidosis and encephalopathy after jejunoileostomy: response to overfeeding and to fasting in humans. Mayo Clin Proc 1984;59:141-145

3. Uribarri J, Oh MS, Carroll HJ: D-lactic acidosis. A review of clinical presentation, biochemical features, and pathophysiologic mechanisms. Medicine 1998;77:73-82

4. Hingorani AD, Chan NN. D-lactate encephalopathy. Lancet 2001;Nov 24:358(9295):1814

5. Sheedy JR, Wettenhall REH, Scanlon D et al. Increased D-lactic Acid intestinal bacteria in patients with chronic fatigue syndrome. In Vivo 2009;23:621-628.

6. Lord RS, Bralley JA. Organic acids; products of dietary carbohydrate. In: Laboratory evaluations for integrative and functional medicine, 2nd edition, 2008. Metametrix Institute, Duluth, Georgia, USA, pp 384-386.

7. Ludvigsen CW, Thurn JR, Pierpoint GL, Eckfeldt JH. Kinetic enzymic assay for D(-)-lactate, with use of a centrifugal analyzer. Clin Chem 1983;29:1823-25

For further details please contact the laboratory at: lab@xxxxbiolab.co.uk