What’s causing an isolated GGT elevation in my patient with an abnormal alkaline phosphatase on her routine admission lab?

Although serum gamma-glutamyl transpeptidase or GGT is a very sensitive test for liver disease, especially of biliary origin, it’s by no means a very specific test. Besides the liver, GGT is found in the kidneys, pancreas, prostate, heart, brain, and seminal vesicles but not in bone (1-4).

Obesity, alcohol consumption and drugs are common causes of GGT elevation (2). As early as 1960s, elevated GGT was reported in such seemingly disparate conditions as diabetes mellitus, congestive heart failure, myocardial infarction, nephrotic syndrome and renal neoplasm (3). Nonalcoholic steatohepatitis, viral hepatitis, biliary obstruction, COPD, liver metastasis, drug-induced liver injury can all cause GGT elevation (1-4).

An isolated GGT does not necessarily indicate serious or progressive liver disease. That’s one reason it’s often not included in routine “liver panel” lab tests (1).
What to do when GGT is high but other liver panel tests such as ALT, AST, albumin, and bilirubin are normal? If your patient is at risk of acquired liver disease, then further workup may be necessary (eg, hepatitis B and C screening tests). Alcohol consumption should be queried. Don’t forget conditions associated with iron overload. If your patient is obese, diabetic or has elevated both lipids, an ultrasound of the liver to look for fatty liver should be considered. In the absence of risk factors, symptoms, or physical exam suggestive of liver disease, isolated GGT elevation should not require further investigation (1).

One good thing that may come out of finding an isolated elevated GGT is to encourage your patient to curb alcohol consumption or lose weight when indicated.

Bonus Pearl: Did you know that GGT activity is thought to increase in alcohol use due to its role in maintaining intracellular glutathione, an anti-oxidant, at adequate levels to protect cells from oxidative stress caused by alcohol?

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1. Carey WD. How should a patient with an isolated GGT elevation be evaluated? Clev Clin J Med 2000;67:315-16. https://www.ncbi.nlm.nih.gov/pubmed/10832186
2. Newsome PN, Cramb R, Davison SM, et al. Guidelines on the management of abnormal liver blood tests. Gut 2018;67:6-19. https://gut.bmj.com/content/gutjnl/67/1/6.full.pdf
3. Whitfield JB, Pounder RE, Neale G, et al. Serum gamma-glutamyl transpeptidase activity in liver disease. Gut 1972;13:702-8. https://www.ncbi.nlm.nih.gov/pubmed/4404786
4. Tekin O, Uraldi C, Isik B, et al. Clinical importance of gamma glutamyltransferase in the Ankara-Pursaklar region of Turkey. Medscape General Medicine 2004;6(1):e16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1140713/
5. Van Beek JHDA, de Moor MHM, Geels LM, et al. The association of alcohol intake with gamma-glutamyl transferase (GGT) levels:evidence for correlated genetic effects. Drug Alcohol Depend 2014;134:99-105. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3909645/

What’s causing an isolated GGT elevation in my patient with an abnormal alkaline phosphatase on her routine admission lab?

My patient has developed isolated eosinophilia without symptoms while receiving an antibiotic. Should I consider discontinuing the antibiotic or can I just continue it as long as she has no symptoms?

Short answer: We don’t really know what’s the best way to manage patients with  isolated (asymptomatic) eosinophilia (IE) that develops during antibiotic therapy. We do know that the majority of patients with IE may never develop hypersensitivity reaction such as rash, renal or liver injuries, but predicting who will or will not get HSRs is a challenge.1-3 Couple of studies may help us in our decision making, however.

In a 2015 study1 involving patients receiving outpatient parenteral antibiotics, eosinophilia was present in 25% of patients during their course of treatment, of whom 30% subsequently developed HSR and 5% developed more than 1 sign of HSR. Patients with IE and subsequent HSR developed eosinophilia earlier in their course of treatment (median 11 vs 17 days) and had a higher peak absolute eosinophil count (~ 850 vs ~700/ ml).  The authors suggested that close monitoring for rash and renal injury in patient with IE during antibiotic therapy be considered, and that medication changes may be necessary when IE is associated with earlier onset of eosinophilia or higher absolute eosinophil count.

In a 2017 prospective study2 of patients with eosinophilic drug reactions (~20% related to antibiotics), the majority (56%) were asymptomatic. Earlier onset of eosinophilia and higher eosinophil count were associated with symptomatic eosinophilia, similar to the aforementioned study. The frequency of patients with IE who went on to have symptomatic eosinophilia when the suspect drug was continued vs those in whom it was not continued remains unclear from these studies.

Ultimately, the decision to continue or discontinue a suspect antibiotic when your patient has new-onset IE should be made on a case-by-case basis, taking into account the severity of the patient’s infection, availability of equally effective and tolerated alternative drugs and the ability to closely monitor for symptomatic disease. The timing of onset of eosinophilia and its peak absolute count may also play a role.

Bonus pearl: Did you know that only 18% of inpatients with cutaneous drug eruptions may have peripheral eosinophilia?4

The author acknowledges the invaluable input of Kimberly Blumenthal, MD in composing this pearl.

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  1. Blumenthal KG, Youngster I, Rabideau DJ, et al. Peripheral blood eosinophilia and hypersensitivity reactions among patients receiving outpatient parenteral antibiotics. J Allergy Clin Immunol 2015;136:1288.1294. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4640981/
  2. Ramirez E, Mdrano-Casique N, Tong HY, et al. Eosinophilic drug reactions detected by a prospective pharmacovigilance programme in a tertiary hospital. Br J Pharmacol 2017;83:400-15. https://bpspubs.onlinelibrary.wiley.com/doi/pdf/10.1111/bcp.13096
  3. Rauscher C, Freeman A. Drug-induced eosinophilia. Allergy Asthma Proc 2018;39:252-56. https://www.ncbi.nlm.nih.gov/pubmed/29669671
  4. Romagosa R, Kapoor S, Sanders J, et al. inpatient adverse cutaneous drug erutpions and eosinophilia. Arch Dermatol 2001; 137:511-12. https://www.ncbi.nlm.nih.gov/pubmed/11295947   



My patient has developed isolated eosinophilia without symptoms while receiving an antibiotic. Should I consider discontinuing the antibiotic or can I just continue it as long as she has no symptoms?

How does excess licorice consumption cause hypertension and hypokalemia?

The active ingredient of licorice, glycyrrhizic acid or glycyrrhizin, is first converted to glycyrrhetinic acid (GRA) in the bowel which is then absorbed. Once in the circulation, GRA inhibits activation of 11 β-hydroxysteroid dehydrogenase 2 (11 β-HSD2), an enzyme in renal tissue that converts active cortisol to inactive cortisone. Without the full action of this enzyme, proper sodium and potassium homeostasis would be difficult because cortisol is just as effective in stimulating mineralocorticoid receptors as aldosterone but with 100-1000 times higher concentration than that of aldosterone! 1-3

Other ways that GRA may cause hypertension and hypokalemia include inhibition of 5 β-reductase in the liver, an enzyme that metabolizes aldosterone and direct stimulation of mineralocorticoid receptors, though overall these mechanisms may not be as important as the effect of GRA on cortisol metabolism in renal tissue.1,2

Besides causing fluid retention, licorice ingestion has also been found to increase systemic vascular resistance possibly by increasing vascular tone and remodeling of the vascular wall, potentiating the vasoconstrictor actions of angiotensin II and catecholamines in smooth muscle, and suppressing vasodilatory systems, including endothelial nitric oxide synthase and prostacyclin synthesis.

It’s no wonder that the FDA issued a statement in 2017: “If you’re 40 or older, eating 2 ounces of black licorice a day for a day for at least two weeks could land you in the hospital with an irregular heart rhythm or arrhythmia.” 5

Bonus Pearl: Did you know that as early as 1951, extract of licorice was reported for treatment of Addison’s disease, a combination of licorice and soy sauce has been reported to be “life-saving” in a patient with Addison’s disease (2007), and GRA food supplementation may lower serum potassium in chronic hemodialysis patients (2009)? 6,7



  1. Sontia B, Mooney J, Gaudet L, et al. Pseudohyperaldosteronism, liquorice and hypertension. J Clin Hypertens (Greenwich) 2008; 10:153-57. https://www.ncbi.nlm.nih.gov/pubmed/18256580
  2. Omar HR, Komarova I, El-Ghonemi M, et al. Licorice abuse: time to send a warning message. The Adv Endocrinol Metab 2012;3:125-138. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3498851/
  3. Penninkilampi R, Eslick EM, Eslick GD. The association between consistent licorice ingestion, hypertension and hypokalaemia: as systematic review and meta-analysis. Journal of Human Hypertension 2017;31:699-707. https://www.ncbi.nlm.nih.gov/pubmed/28660884
  4. Black licorice: trik or treat? https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm 277152.htm
  5. Hautaniemi EJ, Tahvanainen AM, Koskela JK, et al. Voluntary liquorice ingestion increases blood pressure via increased volume load, elevated peripheral arterial resistance, and decreased aortic compliance. Sci Rep 2017;7:10947. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5591274/
  6. Groen J, Pelser H, Willebrands AF, et al. Extract of licorice for the treatment of Addison’s disease. N Engl J Med 1951;244:471-75. https://www.ncbi.nlm.nih.gov/pubmed/14806786
  7. Cooper H, Bhattacharya B, Verma V, et al. Liquorice and soy sauce, a life-saving concoction in a patient with Addison’s disease. Ann Clin Biochem 2007;44:397-99. https://www.ncbi.nlm.nih.gov/pubmed/17594790
  8. Farese S, Kruse Anja, Pasch A, et al. Glycyrrhetinic acid food supplementation lowers serum potassium concentration in chronic hemodialysis patients. Kidney International 2009;76:877-84. https://www.ncbi.nlm.nih.gov/pubmed/19641483
How does excess licorice consumption cause hypertension and hypokalemia?

Does erythrocyte sedimentation rate (ESR) have diagnostic utility in my patient with chronic renal failure?

Short answer: often not! This is because most studies have shown frequently high ESR’s in stable “uninflamed” patients with chronic renal failure (CRF) (including those on dialysis) at levels often associated with infection, connective tissue disease, or malignancy. 1-4  

In fact, in a study involving patients with CRF, 57% of patients had markedly elevated ESR (greater than 60 mm/h), with 20% having ESR greater than 100 mm/h; type or duration of dialysis had no significant effect on ESR levels.1 Another study reported a specificity for abnormal ESR of only 35% for commonly considered inflammatory conditions (eg, infections or malignancy) among patients with CRF. 2

But is it the chronic inflammation in diseased kidneys or the uremic environment that elevates ESR? A cool study compared ESR in CRF in patients who had undergone bilateral nephrectomies with those with retained kidneys and found no significant difference in the ESR between the 2 groups. 4  So it looks like it’s the uremic environment, not diseased kidneys themselves that result in elevated ESR in these patients.

The mechanism behind these observations seem to reside entirely within the patients’ plasma, not the erythrocytes. Within the plasma, fibrinogen (not gammaglobulins) seem to be the most likely factor explaining elevated ESR among patients with CRF. 1,2

Bonus pearl:  Did you know that ESR is nearly 100 years old, first described in 1921? 5


  1. Barthon J, Graves J, Jens P, et al. The erythrocyte sedimentation rate in end-stage renal failure. Am J Kidney Dis 1987;10: 34-40. https://www.ncbi.nlm.nih.gov/pubmed/3605082
  2. Shusterman N, Morrison G, Singer I. The erythrocyte sedimentation rate and chronic renal failure. Ann Intern Med 1986;105:801. http://annals.org/aim/fullarticle/700910
  3. Arik N, Bedir A, Gunaydin M, et al. Do erythrocyte sedimentation rate and C-reactive protein levels have diagnostic usefulness in patients with renal failure? Nephron 2000;86:224. https://www.ncbi.nlm.nih.gov/pubmed/11015011
  4. Warner DM, George CRP. Erythrocyte sedimentation rate and related factors in end-stage renal failure. Nephron 1991;57:248. https://www.karger.com/Article/PDF/186266
  5. Fahraeus R. The suspension stability of the blood. Acta Med Scan 1921;55:70-92. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0954-6820.1921.tb15200.x


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Does erythrocyte sedimentation rate (ESR) have diagnostic utility in my patient with chronic renal failure?