IBD Update January 2015 (Part 2)

1. A retrospective study (Inflamm Bowel Dis 2014; 20: 2292-98) of 217 patients with inflammatory bowel disease(108 infliximab-treated, 109 adalimumab-treated) provides data which indicates that combination therapy (mainly with thiopurines) resulted in higher trough levels and lower antibodies to infliximab (ATI) than monotherapy in patients treated with infliximab (IFX).  This was not evident in the adalimumab (ADA)-treated patients. Overall, approximately 90% of study population had Crohn’s disease.

Key points from this study:

  • The majority of trough level/antidrug antibody levels were drawn due to loss of response.  This is a major limitation of this study.
  • Among IFX-treated patients, those with combination therapy had trough level of 7.5 mcg/mL compared with 4.6 mcg/mL.  In combination therapy patients, the incidence of ATIs was 5.7% compared with 29.8% in monotherapy patients.
  • According to this study, the dose of the immunomodulator (IM) did not significantly influence the infliximab trough level or antibody formation; that is, more than half of patients were receiving “suboptimal dosed IM” and their infliximab levels/ATIs were similar to those who were optimally-dosed.
  • Among those who were receiving combination therapy, the incidence of antibody formation was lower in IFX-treated patients who started IM concurrently with IFX compared with those in which IM was added subsequently.
  • There were many other limitations in this study, including the finding that 94% of monotherapy patients had received previous immunomodulator therapy.

Bottomline: This study suggests that combination therapy is beneficial for patients receiving infliximab (in agreement with the previous SONIC study) and may not be beneficial for patients receiving adalimumab; however, only a well-designed prospective study

2. Inflamm Bowel Dis 2014; 20: 2266-70.  This study with 749 patients from Sweden showed that a large number of inflammatory bowel disease patients did not receive with iron supplementation: “Only 46% of patients with anemia were treated with iron supplementation or blood transfusion.”  This study showed frequent persistence of anemia one year after diagnosis, especially in children. At time of diagnosis, 55% of children and 27% of adults had anemia and 28% and 16% at one year followup, respectively.

My take: Treatment of the underlying IBD, often helps anemia.  However, in some patients treating the anemia with iron may help improve symptoms as much or more than other aspects of treatment.

3. Inflamm Bowel Dis 2014; 20: 2433-49.  Reviews pain management approaches for patients with IBD. The article emphasizes how pain can be multifactoral and that opiod-induced hyperalgesia may worsen pain.

Related blog posts:

 

Bryce Canyon

Bryce Canyon

 

Less Red Meat, More Anemia

The title of this entry is not particularly surprising.  A recent study (JPGN 2013; 57: 722-27) showed that among 263 children (1.5-6 years in age) in Jerusalem, that anemia was present in 11.2%, iron deficiency in 22%, and iron-deficiency anemia in 3.7%.

Key finding:

Children with extremely low red meat consumption had 4-fold higher rates of iron deficiency than those who consumed ≥2 servings per week.  Poultry intake was not protective.

Bottomline: As more families choose a ‘health-conscious diet,’ iron deficiency may become more frequent.

Related blog entry: Help with hepcidin | gutsandgrowth

True red flags in recurrent abdominal pain

For pediatricians and pediatric gastroenterologists alike, identifying which children need additional workup for recurrent abdominal pain (RAP) is facilitated by recognizing “red flags.”  “Red flags” are clinical features that indicate a higher likelihood of a nonfunctional disorder.  A recent study notes that reports of waking from sleep and joint pains do not distinguish functional from nonfunctional causes of RAP (J Pediatr 2013; 162: 783-7).

This study, performed between 2005 to 2008, had patients presenting to an outpatient pediatric gastroenterology clinic for RAP prospectively complete a detailed questionnaire. Data, though, was extracted retrospectively. In this population (n=606), 85% were Caucasian.  After their evaluation, patients with functional GI diseases (FGID, n=478) were compared with patients confirmed with Crohn’s disease (CD, n=128).  All FGIDs underwent biochemical testing, 41% had upper endoscopy, and 32% underwent colonoscopy.

Additional key findings:

  • Using a tree analysis, the cumulative sensitivity for Crohn’s disease was 54% with the presence of anemia, 78% when blood in stool was added to anemia, and 94% when weight loss was added as well.
  • FGID patients were more likely to report stress and headaches, more likely to have family history of FGID, and less likely to have anemia, hematochezia, or growth issues.
  • FGID patients were more likely to experience vomiting.

The sensitivity and specificity of these symptoms/signs will vary based on the population.  For a general pediatric clinic, it is likely that the sensitivity of these red flags would remain high; the specificity would likely be lower than in a pediatric gastroenterology office due to the increased prevalence of functional diseases in the general pediatric setting.

Related blog posts:

Are we missing Vitamin B12?

This is the question that I wonder after reading a recent review (NEJM 2013; 368: 149-60) -especially since effective treatment is readily available.

While vitamin B12 deficiency is most common in individuals 70 to 80 years, it affects all age groups.  A particularly vulnerable group are infants of mothers with vitamin B12 deficiency.  These infants may be born with deficiency or it may develop if exclusively breast-fed, usually between 4 and 6 months of age.  Indications of this deficiency include failure of brain development, poor growth, hypotonia, and feeding difficulties.  Some infants develop tremors, lethargy, and hyperirritability.  Imaging may show atrophy and delayed myelination.

Mothers who are at most risk:

  • unrecognized pernicious anemia
  • history of gastric bypass
  • short gut syndrome
  • long-term vegetarian or vegan diet

Other pediatric conditions that cause B12 deficiency: ileal resections, Imerslund-Grasbeck syndrome (ImerslundGräsbeck syndrome (selective vitamin B12 malabsorption ..), inflammatory bowel disease, and pernicious anemia.

Other Key Points from this review:

  • B12 deficiency causes reversible megaloblastic anemia, demyelinating neurologic disease or both
  • B12 deficiency is the major cause of hyperhomocysteinemia in countries with folate-fortified food and contributes to a risk of vascular disease and thrombosis
  • Autoimmune gastritis (pernicious anemia) is the most common cause of severe deficiency (in adults).  Tests to determine underlying reason for B12 deficiency include the following: anti-intrinsic factor antibodies (must be checked off treatment for at least 7 days), anti-parietal cell antibodies -both help detect pernicious anemia, gastrin level (high level) & pepsinogen I (low levels) both suggestive of atrophic gastritis.  The Schilling test of radioactive B12 is no longer available.  Endoscopy is frequently performed in adults with B12 deficiency.
  • Methylmalonic acid (MMA) is the best indicator for untreated B12 deficiency; MMA >400 nmol/L has 98% sensitivity for B12 deficiency.  Other causes of increased MMA include renal failure and volume depletion.
  • Serum B12 has poor sensitivity and specificity -though performs adequately at higher cut-off value (<350pg/mL has 90% sensitivity)
  • Many individuals require lifelong treatment with either parenteral B12 or high-dose oral tablets (see article for dosing recommendations)

Additional references:

  • -J Pediatr 2010; 157: 162.  B12 deficiency in newborns –especially if mother has had bariatric surgery or vegan diet.
  • -J Pediatr 2001; 138: 10 (review) At risk for deficiency: strict veggie, abnl absorption (gastric resection, pernicious anemia), long term PPI, bacterial overgrowth, ileal disruption (Crohn’s), or ileal receptor d/o (Imersund-Grasbeck),  inborn B12 metabolism d/o

Clinical Sx: FTT, weakness, anorexia, neuro/psych sx, macrocytic anemia, pancytopenia, glossitis, vomit/diarrhea

Dx: low vit B12, incr methylmalonic acid & incr homocysteine.  MMA specific for B12; homocysteine incr also if folate deficient.

If Vit B12 deficient, reason for this needs to be determined.

Inadequate treatment of anemia in IBD

In some patients with inflammatory bowel disease (IBD), treatment of anemia associated with IBD sometimes results in more symptomatic benefit than treatment of the IBD.  Yet, anemia remains common in IBD, both in children and adults (Inflamm Bowel Dis 2012; 18: 513-19).

Using a cross-sectional observational study design, a tertiary adult and pediatric IBD center reviewed consecutive clinic patients in April 2009.  The prevalence of anemia was 70% (41/59) children, 42% (24/54) adolescents, and 40% (49/124) adult.  In addition, iron deficiency anemia was more common in the pediatric population: 36/41 children and 20/23 adolescents.  In the adults with anemia, only 55% (27/49) were iron deficient.  One of the key determinants of anemia was disease activity.

Interestingly, among patients with iron deficiency, younger age was inversely associated with treatment with iron therapy: 13% of children, 30% of adolescents, and 48% of adults.

Other important aspects of anemia in IBD:

  • Anemic patients can have quality of life scores as poor as those seen in malignancy
  • Almost all IBD patients will respond to either oral or parenteral iron.  Erythropoetin reserved for patients who do not respond to parenteral iron.

Additional references:

  • -NEJM 2005; 352: 1011. Anemia algorithm.  If transferrin saturation <16%, check ferritin.  If ferritin less than 30, then patient with Fe-deficiency; if >100, anemia of chronic disease.  If 30-100, could check soluble transferrin receptor (level of sTranReceptor/log ferritin < 1 is c/w anemia of chronic disease whereas when > 2, c/w combined Fe-def anemia and anemia of chronic disease)
  • -JPGN 2010; 51: 708. 25-50% still anemic 1yr post IBD diagnosis.
  • -IBD 2007; 13: 1545-53. Guidelines for anemia mgt w IBD. Max oral absorption is 10-20mg/day; thus IV iron often needed. Goal for iron Rx is transferrin saturation of 15-50% and ferritin > 30 mcg/L (>100 if active inflammation). Anemia of chronic disease likely if TS <16% and ferritin > 100. Rec IV iron Rx prior to use of Epo. IV iron effective alone in 70-80%. Epo if no response to IV iron & Hgb <10. Consider folic acid & B12 deficiency if high MCV. AZA/6MP usually associated with pancytopenia not isolated anemia.
  • -Gastroenterology 2011; 141: 846. Ferric carboxymaltose better than iron sucrose (Ferrlecit/Venofer) b/c can use higher dose & give more rapidly.