NASPGHAN Notes –Last Word for this Year

This blog entry has abbreviated/summarized several presentations. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.

IBD Treatment: Targets for the Modern Age –Eric Benchimol (Children’s Hospital of Eastern Ontario)

Goal: Review mucosal healing and best targets to measure to predict prognosis

Treat-to-target:

  • Regular assessment of disease activity using objective outcome measures.
  • Adjust treatment if not accomplishing goal.
  • Proven helpful in rheumatoid arthritis, hypertension, diabetes, and hypercholesterolemia.

Old targets:

  • “Clinical remission”
  • “Feeling better”
  • Indices: PCDAI, CDAI, Harvey-Bradshaw
  • Problem: Active disease is not well-predicted by symptoms or laboratory markers
  • 2nd Problem: Active symptoms not always due to active IBD (could be due to functional complaints)
  • PUCAI score in ulcerative colitis does reflect ulcerative colitis severity fairly well

New Targets

  • High correlation with outcomes
  • Cost-effective
  • Available

Is mucosal healing achievable?   If you were scoped and adjustments made in therapy, then much higher rate (HR >4) of remission. Bougen, Clin Gastroenterol Hepatol 12: 978.  Endoscopy may be best way to assess mucosal healing.  Since it is invasive, efforts have been made to identify surrogate markers.

Treat-to-Target Algorithm

Treat-to-Target Algorithm

Surrogate Markers

  • Ultrasound –can be useful but operator-dependent
  • MRE had 83% accuracy for endoscopic remission: Gastroenterol 2014; 146: 374.
  • Calprotectin not as accurate in children? Am J Gastroenterol 2014; 109: 637. Sensitivity high 97%, specificity for remission 68%
  • CRP –if elevated, higher risk of complications or surgery. However, sensitivity is much lower for disease activity than calprotectin/imaging studies for active disease
  • Drug levels. Therapeutic IFX trough levels (and adalimumab) are highly predictive of mucosal healing.

Bottomline (my interpretation): Resolution of clinical symptoms and improvement in bloodwork is not good enough.  When/timing to assess with sensitive surrogate markers is still uncertain.  In many patients, endoscopy is needed to assure adequate improvement; however, in others, a followup imaging study (eg. MRE) or sensitive stool assays may be the best approach.

A related story (from AGA’s Today in Medicine email feed & pointed out to me by Ben Gold) indicates that estimation of clinical symptoms is not accurate:

Survey Suggests Severity Of IBD Is Underestimated By Gastroenterologists.

MedPage Today (10/31, Walsh, 186K) reports that survey results presented at a medical conference indicate that “the severity of inflammatory bowel disease is significantly underestimated by gastroenterologists.” Researchers found that “a total of 55% and 67% of physicians who participated in a web-based survey rated cases of Crohn’s disease and ulcerative colitis as being mild when they were actually moderate.” Meanwhile, “for case studies that represented severe disease, 76% and 81% of the physicians gave ratings of either moderate or mild for Crohn’s disease and ulcerative colitis, respectively.”

 

Related blog posts:

Risk Stratification in Pediatric IBD: Are we there yet? Jeffrey Hyams (Connecticut Children’s

Initially, Dr. Hyams described the exploding head syndrome; many attendees might have thought they had this due to information/”big data” overload, but this syndrome is a sleep disorder/parasomnia event.  Here’s a link to the image from his talk.  Then, Dr. Hyams reviewed data on risk stratification:

  • Mutations: Some genetic mutations are associated with disease severity
  • Still needed: specific pediatric data
  • Microbiome: Some profiles associated as prognostic factors in pediatric RISK study
  • Early anti-TNF associated with improved outcomes (using propensity analysis) Gastroenterol 2014; 146: 383.

Bottomline: Not there yet with risk stratification. Many factors environmental, genetic susceptibility, immune response, and treatment need to be sorted out with “big data.”

Key Clinical Questions for your practice at this time:

  • Does this patient have known risk factors for doing poorly?
  • Am I using current therapies properly?
  • What is the risk of undertreated disease? This needs to be considered with discussion of safety of IBD meds.

Cross Examination of Cross-Sectional Imaging in IBD –Sudha Anupindi (Radiology/CHOP)

  • For the most part, barium studies discouraged (eg. UGI/SBFT) by speaker; radiation ~1 mSv.
  • CT (conventional) widely available and easy –if needed urgently/middle of night.

Initial presentation: imaging of choice

  • MR enterography –no radiation, better contrast resolution, best for perianal disease, able to evaluated peristalsis. Two limitations: cost, interpretation
  • CT enterography –fewer motion artifacts (0.6 seconds), lower cost, increased availability, better spatial resolution radiation reduced with current technology at most Children’s hospitals: 1-2 mSv

Abdominal ultrasound holds promise as alternative imaging with lower cost.

 

Basic Science Year in Review –#NASPGHAN 2014

John Barnard –Basic Science Year in Review

“Emerging Trends and Provocative Findings in Basic Science”

This blog entry has abbreviated/summarized this terrific presentation. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.  To minimize these issues, I have placed a link to most of Dr. Barnard’s slides which he shared:

2014 John Barnard Slides

“Big Data” –big increase in “big data” cited in pubmed over past year.

  • Good read on this subject: Foreign Affairs: The Rise of Big Data Kenneth Cukier

Scientific fraud –more attention to this issue this past year. Two papers in Nature were retracted. One researcher committed suicide and one arrested. Scientific fraud undermines important messages & ruins credibility of other important advances.

CRISPR-Cas9: Gene editing.  CRISPRs –“RNA guides”  Cas9: “molecular scissors” (endonucleases)

Genome editing has never been easier.”  Examples:

  • Cell Stem Cell 2013: 13: 653-58. “Functional repair of CFTR by CRISPR-Cas9”
  • Also, genome editing has been used in mouse model of tyrosinemia.

Liver regeneration in zebrafish. Implication: Liver cells will be regenerated in humans. Gastroenterol 2014; 146: 789.

Microbiome Big Data:

  • J Clin Invest 2014; 124: 3617. This was a very important and complex study.  The slides explaining this study start at slide 35.
  • Pediatric Crohn disease exhibit specific ileal transcriptome and microbiome signature.
  • RISK study (CCFA). Treatment-naïve, 28 sites.
  • 1281 ileal host genes in ileocolonic Crohn’s, 1055 in Colonic Crohn’s had ileal host genes =82% similar, 232 host genes in ulcerative colitis –18% similar to ileocolonic Crohn’s.
  • Tissue microbiomes are where changes are noted; changes are not evident in luminal microbiome.
  • Antibiotics worsen dysbiosis.
  • Microbiome at diagnosis strongly correlates with Crohn’s disease.

Microbiome –affects the entire body:

  • J Clin Invest 2014; 124: 3391. Incorporation of microbes with genetically-engineered E coli can prevent obesity in mice

Recommended Reading by Dr. Barnard: “Missing Microbes” How the overuse of antibiotics is fueling our modern plagues. Martin Blaser

 

“Genetic Testing and the Future of Pediatric Gastroenterology”

Last night, a symposium on “Genetic Testing and the Future of Pediatric Gastroenterology” sponsored by Children’s Healthcare of Atlanta took place.  The speakers included Dr. Ben Gold from our pediatric GI group (GI Care for Kids), Dr. Saul Karpen and Dr. Subra Kugasthasan (Emory), and Dr. Robert Heuckeroth (CHOP).

This blog entry has abbreviated/summarized the presentations. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.  All of the speakers had terrific presentations.

GI Genetic Testing –Subra Kugathasan

Reasons for genetic testing:

  • Predicting prognosis: predicting stricturing/fibrosis in Crohn’s, predicting cancer in ulcerative colitis; BRCA1 in breast cancer
  • Choosing the right medicine: pharmcogenomics
  • Precision medicine: prevention of disease, slowing progression of disease.

Examples in current medicine:

  • Recurrent pancreatitis –novel mutations identified in SPINK1.  Also now hereditary pancreatitis may be due to mutations in CPA1, GGT1, CLDN2, MMP1, MTHFR in addition to CTRC, SPINK1, CFTR, and PRSS1.
  • Inflammatory bowel disease (IBD):IL10 Receptor mutation , TTC7A –>VEO IBD; IPEX gene (can worsen with immunosuppression). Panel testing now available for 40 genes –4 of 22 patients identified with IBD.  Identifying cause of VEO IBD may lead to treatment: bone marrow transplantation.
  • IBD: CLIA/CAP certified Emory Genetics panel ~50 genes (genetics.emory.edu/egl/tests/view.php?testid=4420). Dr. Kugathasan indicated that this testing is likely to be a better 1st step then exome testing. Yield with exome sequencing (in highly selected populations) about 25% at this time but likely to increase. If negative, can proceed with whole exome sequence.  Numerous problems with exome sequencing; for example, exome sequencing may identify genes of unknown significance and identifying genetic problems unrelated to clinical issue.

Who/When to test?

  • Very early onset disease (<10 years), atypical presentation, perhaps treatment-refractory.

Take-home point: “All GI diseases have genetic testing in future.” Testing for highly selected patients for gene defects can be accomplished with gene panel and if negative, whole exome testing.

Related blog posts:

Liver: Cholestatic & Metabolic Diseases of Infants and Children —Saul Karpen

Potential areas for genetic testing:

  • Neonatal cholestasis: PFIC, Metaboic, Biliary Atresia
  • NAFLD
  • Transplant

“Why bother…they all get transplanted anyway…”  According to Dr. Karpen, this view needs to be reconsidered.

Neonatal cholestasis:

  • (Front Pediatr 2014; 2: 65)  41% with biliary atresia, 13% idiopathic, and a lot of others.  N=82. Other etiologies: Genetic disorders; Biliary disease (eg. Caroli), transporter defects (PFICs/BRICs), Metabolic (Niemann-Pick C, tyrosinemia, HFI, Peroxisomal, GSDs, Peroxisomal, Mitochondrial, A1AT). Thus, panels to identify these disorders can be very helpful.
  • Emory Cholestasis 56+ Gene Panel. Testing is cheaper than endoscopy

PFIC: Progressive Familial Intrahepatic Cholestasis

  • PFIC1: ATP8B1 (Byler) –besides cholestasis, patients often with diarrhea, hearing loss, very itchy; can have cirrhosis at 2 years of life
  • PFIC2: ABCB11 (BSEP deficiency) –can have cirrhosis at 6 mo, prone to HCC (as early as 13 mo), very itchy
  •  PFIC3 (high GGT) ABCB4 –can have cirrhosis at 5 mo, can cause problems at later ages as well (eg. intrahepatic cholestasis of pregnancy, gallstones); increase risk for HCC/cholangiocarcinoma.
  • Identifying PFIC (could mimic PSC) and BRIC (Benign Recurrent Intrahepatic Cholestasis)–is helpful in following patients for specific management when symptoms recur and to screen for complications (eg. HCC).

Biliary Atresia:

  • No clear genetics in most
  • Laterality defects in 5-10% -asplenia/polysplenia, cardiac defects
  • GPC1 gene is a susceptibility gene in zebrafish
  • ADD3 gene identified in Han Chinese OR 2.38 –may be a susceptibility gene. (30% of cases, 17% of controls)

NAFLD: Associated with increased mortality compared with matched controls. Patients develop thicker atherosclerotic plaques. PNPLA3 gene identified as a susceptibility gene for NAFLD and is highly prevalent in Hispanic populations.  Similarly, PNPLA3 has been associated with NASH in Italian populations.  If you have this genotype, this increases risk of liver fat in the face of increased sugar consumption.

Transplant medicine: Deoxyguanosine Kinase Deficiency (DGUOK) –rapid sequencing for this gene pretransplant –If positive, should not be transplanted. These individuals have systemic disease that cannot be cured with liver transplantation.

Who/When for genetic testing?: DGUOK in liver failure patients, and in infants without diagnosis after liver biopsy/exclusion of A1AT

Take-home message: Genetic testing has a role in pediatric liver disease and it is affordable.

Related blog posts:

GI –Single Microbes to the Microbiome and GI Disease —Ben Gold

  • Described why changes in our environment can trigger development of disease due to changes in microbiome (eg. immigrants/children with IBD in developed countries at much higher rate than at developing countries)
  • Discussed Helicobacter pylori –‘how a single microbe which may have been good turned bad’
  • Described pathogenesis. What you get exposed to early on may lead to an exaggerated response by T-cells/immune system.  Healthy microbiota is critical to train the immune system via GALT to protect host and decrease the chances for immune overexpression.

Key points:

  • 100 trillion bacteria that live in our GI tract. 10x number of human cells in our body and 100x as many genes as there are in the human genome.  Partnership between humans and their microbiome developed over thousands of years.
  • Vaginal delivery is NOT sterile. Are there consequences to C-section? Food allergy for infant –OR 2.5 if Mom with food allergy delivers vaginally vs OR 7.8 if Mom has food allergy and delivers via C-section. Also, some data indicates increased risk of EoE if born via C-section.  From DAY 1, microbiome can be influence by environmental factors.
  • Influencing microbiome happens mainly during first three years of life.

Why the microbiome is so important/more pointers:

  1. Since 1950, there has been a huge decline in infectious diseases like measles, mumps, hepatitis A, tuberculosis, etc
  2. Coincident with these decreases there has been increased multiple sclerosis, Crohn’s disease, asthma, food allergy, autoimmune diseases
  3. Sanitized food supply, decrease in naturally fermented foods, urban lifestyle, antibiotics, C-section all lead to lower microbial exposure and altered intestinal microbiota. This in turn may lead to an inadequate immune response.
  4. Elie Metchnikoff 1845-1916: suggested ingested bacteria could be healthy. Probiotics/prebiotics are not a new idea!
  5. Obese patients had very high levels of Firmicutes and low Bacteroidetes.
  6. Fecal microbial transplantation (FMT)–reseeding GI microbiome. FMT may be beneficial to many diseases and is being  studied.

Helicobacter pylori -evidence of H pylori as far back as 60,000 years ago and has evolved with humans. H pylori may have helped provided a positive immune response in children and adults.

Bottomline: Human genetic diseases may be heavily influenced by the 300 trillion bacteria and their genes; these bacteria are susceptible to environmental disease.

Related blog posts:

 

Genetic Basis of Motility —Robert Heuckeroth

  • Basic machinery controlling motility described –enteric neurons, muscles, pacemaker cells.
  • Very little clinical overlap between modern genetic testing and applicable motility disorders: achalasia, gastroparesis, pseudoobstruction, Hirschsprung’s or irritable bowel
  • Focused testing for suspected diagnosis is being displaced by broader testing in serious disease, especially since more extensive genetic testing may be more cost-effective. When to do exome sequencing?

Hirschsprung’s disease:

  • 1:5000 children.
  • 100X higher risk in Down Syndrome.
  • Prenatal testing not helpful at this time. There may be >360 genes that increase risk (variable degree of risk) of Hirschsprung’s disease; hence prenatal testing not that helpful at this time.
  • 30 associated genetic syndromes with Hirschsprung’s, >12 known gene defects.  Hirschsprung’s disease: 25% with RET haploinsufficiency.  RET haploinsufficiency –increases risk of Hirschsprung’s disease >2500-fold risk.
  • Gene environment interactions can increase risk of developing Hirschsprung’s disease –if vitamin A deficient, mice with increased risk.
  • RET gene –>too little RET increases risk of Hirschsprung’s
  • RET gene –>too much RET increases risk of MEN2B, MEN2A.  Though 7.5% of MEN2A have Hirschsprung’s –works out to be 1 in 100 kids with Hirschsprung’s have MEN2A mutations.  ??test for this??

Pseudoobstruction genetic basis– a number of genes identified, including ACTG2 (smooth muscle actin gene).  If you understand etiology, this may lead to prevention and treatment.

Take-home message: Currently biggest problem with genetic testing, especially with motility disorders, is identifying genetic defect of unknown significance.  Thus, testing needs to be done as part of research studies.

Related blog posts:

 

 

 

Anti-TNF Therapies: Safe in Pregnancy

According a review (Inflamm Bowel Dis 2014; 20: 1862-69) of 5 studies with 1216 patients, “the use of anti-TNFα therapy does not seem to increase the risk of unfavorable pregnancy outcomes among women with IBD, although the optimal timing of therapy through pregnancy and the postpartum period was not assessed.”

Other important points:

  • “Current recommendations suggest that anti-TNFα therapies be continued during the first 2 trimesters of pregnancy.”  Withholding of infliximab and adalimumab during the third trimester is due to concerns of increased drug levels in infants.
  • Live virus vaccination should “be avoided for the first 6 months in children who had exposure to anti-TNFα therapies in utero.”

Related blog posts:

Adalimumab Gains FDA Approval for Use in Children

Medications used in pediatrics often do not have a “pediatric indication” on their FDA-approved labeling.  Until recently, one of those medications included adalimumab (Humira).

Sept 25, 2014 (From MSN Money):  The Food and Drug Administration cleared Humira as a treatment for moderate to severe Crohn’s disease in children ages 6 and older when those children haven’t been helped by other treatments, AbbVie said. The North Chicago, Illinois, company said Humira can be administered at home, unlike similar drugs used to treat the condition. During the second quarter, revenue from Humira jumped 26 percent to $3.29 billion.

Related blog post:

More Lessons in TNF Therapy (Part 2)

Another useful study (Clin Gastroenterol Hepatol 2014; 12: 1474-81, editorial 1482-84 [podcast available: http://www.gastro.org/cghpodcast%5D) on infliximab (IFX) usage addresses the issue of reinitiating IFX therapy after a “drug holiday.”

The authors conducted their retrospective single-center study in Belgium.  This detail is important as interruption of therapy is more common in Europe where agents like IFX are often stopped when patients are doing well.  In the U.S. stopping IFX occurs more commonly when there are antibodies to infliximab (ATIs) or increased clinical symptoms.  In this particularly study, 22% were restarted on IFX after loss of response (despite dose optimization) and the remainder had been stopped either due to remission, pregnancy or patient decision. Also, in their center, patients do not receive IFX unless they were allergic or refractory to steroids and/or immunomodulators for a minimum of 3 months.

In total there were 128 patients (105 with Crohn’s and 23 with ulcerative colitis).

Key findings:

  • Reintroduction of IFX resulted in a clinical response in 84.5% at week 14, 70% at 1 year, and 61% at more than 4 years.
  • Higher response was noted in those who discontinued because of remission: 90% at week 14, 77.5% at 1 year, and 66.6% at more than 4 years.
  • In patients with prior loss of response, 45% had response to reintroduction of IFX at 1 year.
  • 15 patients had acute infusion reactions, seven of these were severe.
  • ATI-positivity was associated with a higher risk of infusion reaction, though most ATI-positive patients did not develop a reaction.  Particularly in ATI-positive patients, the editorial recommends a “slow infusion protocol and possibly steroids before administration of the drug.”
  • The editorial states: “it seems reasonable to check drug levels and antibodies before the second infliximab dose.” Trough levels >2 mcg/mL and undetectable ATIs early after restarting the drug were associated with good responses. “For patients with high ATIs (≥9.1 U/mL), another drug should be considered.”
  • Among those with detectable ATIs, response at 1 year was noted in 54.8%.
  • Immunomodulator cotherapy had a beneficial effect.

Bottomline: This study provides useful insights for patients who need to reinitiate IFX treatment.  In addition, some IFX failures may be able to resume IFX after a drug holiday.

Related blog posts:

More Lessons in TNF Therapy (Part 1)

More data has been published regarding postoperative therapy with infliximab (IFX) in Crohn’s disease (Clin Gastroenterol Hepatol 2014; 12: 1494-1502, editorial 1503-6).

In this prospective, open-label study with at least 5 years of followup, 24 patients who were previously randomly assigned to receive IFX or placebo for 1 year after ileocolonic resection were given the option of continuing IFX or stopping IFX (“watch and wait approach”).  This was a strange study and perhaps mirrors clinical experience in that consistent usage of IFX was not maintained in the majority; in addition, there was not a set pattern with regard to thiopurine usage.

Of 11 patients who received IFX during the first year after surgery, 8 elected to stop IFX and all 8 experienced endoscopic recurrences at a mean of 18.2 months, including 5 who needed surgery.  Of 13 patients who received placebo during the first year after resection, 12 elected to initiate IFX at 1-year entry point;  7 of those responded with endoscopic remission. Overall, the mean percentage of time that a patient received IFX was similar between those initially assigned to IFX or placebo (50.3% vs. 53%).

Key findings:

  • Among those originally assigned to the IFX group, there was a longer mean time to first endoscopic recurrence (1231 days vs. 460 days in placebo group).
  • Colonoscopy identified recurrent disease in 22.2% of patients receiving IFX compared with 93% off IFX.  That is, throughout the study there were 84 colonoscopies.  If one was receiving IFX at the time of the colonoscopy, the adjusted rate ratio for being in remission while on IFX was 13.47.
  • Among patients who received IFX for at least 60% of the full study period, they had fewer surgical recurrences: 20.0% compared with 64.3% (5 of 8).
  • Recurrence was similar for patients receiving IFX monotherapy or in combination (though small numbers preclude a definitive assessment).
  • None of the three patients who continued IFX from the beginning have required an operation in the past 8 years.

One can speculate that the main reason why so many placebo-treated patients (12 of 13) elected to start IFX was that there was evidence of recurrent disease; conversely, many of the patients who received IFX postoperatively were in remission and opted for a watch-and-wait approach subsequently.

Study limitations: small numbers, open-label design, changes in therapy at patient’s physician discretion, and no restrictions on use of concomitant medications.

The associated editorial recommends the use of IFX postoperatively in high-risk patients (perforating disease, smokers, >1 surgical resection) and notes that therapy should be started 2-4 weeks after surgery because IFX is “less effective in preventing medical recurrence if started after endoscopic recurrence.”  The editorial suggests that low-risk patients should undergo a 6- to 12-month endoscopic evaluation.  Though, “we urgently need data from large prospective studies such as the PREVENT trial” (NCT01190839) as well as the POCER study.

Bottomline: Infliximab, administered within 4 weeks of an ileocolonic resection, reduces postoperative recurrence of Crohn’s disease and helps prevent further surgeries.  Studies (like this one) with long followup are essential to determine the effectiveness of anti-TNF (tumor necrosis factor) therapies.  It remains unclear whether only “high-risk” patients should receive anti-TNF therapy or whether these agents should be used more broadly.

Related blog posts:

ImproveCareNow Video

A recent (short ~2:30) ImproveCareNow (ICN) Video explains how ImproveCareNow is a forward-thinking network and how it has the potential to lead to better outcomes for children with inflammatory bowel disease.

If you are part of ICN, this video may help explain to your patients what ICN is all about.

Early Results of FMT for IBD -Any Efficacy?

As more data emerges on fecal microbiota transplantation (FMT) for inflammatory bowel disease in well-designed trials, it is not clear if FMT will be effective.  A summary of some recent abstracts is available at this link to Gastroenterology and Endoscopy News: Fecal Transplants for IBD Show Mixed Results in Trials

One trial with 53 patients with mild to moderate UC (27 randomized to FMT, 26 to placebo) once weekly for six weeks showed similar results in both groups with 7 FMT patients and 8 placebo recipients experiencing improvement of at least 30% in their Mayo scores.  Dr. Lawrence Brandt said, “It may be that we need to look at the patient’s unique bacterial composition and determine which organisms need to be replaced and formulate FMT accordingly.”

Related blog posts:

Why Adding Vitamin D May Not Help IBD

Despite all of the accolades that vitamin D has received, the fact that low vitamin D is associated with worse outcomes, in a number of disease states, does not prove causality. A recent article indicates that vitamin D is likely more of a marker of disease activity than a mediator of disease activity in inflammatory bowel disease (IBD), and specifically Crohn’s disease (CD) (Inflamm Bowel Dis 2014; 20: 856-60).

Background: Binding sites for the vitamin D receptor (VDR) have been “identified in genes associated with CD, and vitamin D has been shown to enhance the production of interleukin-10 (IL-10) and induction of regulatory T-cells.”

Design:The authors prospectively collected samples of 37 CD patients; the mean age in those with active disease (n=20) was 34 years and it was 30 years in those with inactive disease. In 8 patients with active disease, vitamin D levels were measured at the time of active inflammation (day 0) and at 14 days after receiving infliximab (day 14).

  • Key finding in these 8 patients: Vitamin D (25-OH) was 23 ng/mL on day 0 and 40 ng/mL 2 weeks later.  Only 1 of these 8 patients was taking a vitamin D supplement.
  • Key finding in the entire cohort: in the active disease group mean vitamin D level was 27 ng/mL compared with 38 ng/mL in those in remission (P=0.02).

Take-home point: There is an inverse relationship between vitamin D levels and disease activity.  However, the early increases in vitamin D levels with clinical response to anti-TNF therapy suggests that a major mechanism of vitamin D deficiency is related to the burden of systemic inflammation.  Hence, repeat testing when patients are in remission may obviate the need for vitamin D supplementation in many patients.

Related posts: