Quantifying the Risk of Serious Infections in Pediatric Patients with Inflammatory Bowel Disease

JF Ludvigsson et al. J Pediatr 2021; 238: 66-73. Open Access PDF Serious Infections in Pediatric Inflammatory Bowel Disease 2002-2017—A Nationwide Cohort Study

This study utilized the Swedish nationwide health registry (2002-2017; n = 5767 with IBD) and controls from the general population (n= 58,418). One reason for this study is the increased frequency and changing patterns of immunosuppressive medications that are being used in pediatric IBD. Key findings:

  • 672 serious infections (38.6/1000 person-years) occurred among the children with IBD compared with 778 serious infections in the control group (4.0/1000 person years; adjusted HR 9.46 ). HRs were increased for children with ulcerative colitis 8.48, Crohn’s disease 9.30, and IBD unclassified 12.1
  • Particularly high HRs were also seen in the first year of diagnosis with HR of 12.1 and n children with IBD undergoing surgery, HR 17.1. This 17-fold risk translates to an average of 6 per 100 children having a serious infection among those with operations.
  • 340 of the 672 serious infections were gastrointestinal, including 34 due to Clostridium difficile
  • 20 opportunistic infections were identified during 19,000 person-years

Potential risk factors for infection, besides medications, include malnutrition, chronic inflammation, impaired response to vaccination, and dysregulation of immune responses. A limitation of this study is ascertainment bias as families/patients with underlying disease may be more likely to seek medical attention for otherwise self-limited infections.

My take: This report confirms and quantitates daily clinical practice: children with IBD are more frequently hospitalized due to infections.

Related blog post: Infection or Flareup in IBD: GI PCR Panel Helps

Stillbirths associated with COVID-19: Stillbirths increased from 5.6 per 1,000 baseline to 8 per 1,000 if COVID-19 anytime during pregnancy and to 22.6 per 1,000 if COVID-19 infection began within 28 days of birth in a study of more than 130,000 Scottish births (12/1/20-10/21/21).
Reference: Stock, S.J., Carruthers, J., Calvert, C. et al. SARS-CoV-2 infection and COVID-19 vaccination rates in pregnant women in ScotlandNat Med (2022). https://doi.org/10.1038/s41591-021-01666-2

Bring Out the Big Guns: Treating Infections with Cirrhosis

A recent study (M Merli et al. Hepatology 2016; 1632-39) indicates that health-care associated infections (HCA) in the setting of cirrhosis respond more favorably to broad-spectrum antibiotics.  In this prospective study of 96 randomized patients, in-hospital mortality was improved in the broad-spectrum group (6%) compared to the standard group (25%).  There was a similar multidrug-resistnace rate (50% broad spectrum compared with 60% in standard group).

Table 1 lists the antibiotic selection.  In the broad spectrum treatment, this almost always included imipenem/cilastin (I/C); with spontaneous bacterial peritonitis (SBP), I/C was combined with vancomycin, and with pneumonia it was combined with both vancomycin and azithromycin.  In contrast, the standard group’s main medication was augmentin (with added azithromycin for pneumonia) or cefotaxime for SBP.

My take: Does this study show that infections in the setting of cirrhosis are becoming more difficult to treat? Probably. How much these findings can be extended to the pediatric population remains uncertain.

Somewhat related topic: Primary prophylaxis of Variceal Bleeding in Children –Summary of the Baveno VI Pediatric Satellite Symposium.  BL Shneider et al. Hepatology 2016; 63: 1368-80. Key point: “there are few pediatric data…therefore, no recommendations for primary prophylaxis with endoscopic variceal ligation, sclerotherapy, or nonspecific beta-blockade in children was proposed.”

Silver Comet Trail

Silver Comet Trail

“Origins of Cystic Fibrosis Lung Disease”

Origins of Cystic Fibrosis Lung Disease — NEJM (NEJM 2015; 372: 351-62) is a good read.  The authors note that the basic defect in Cystic Fibrosis (CF), the loss of the cystic fibrosis transmembrane conductance regulator (CFTR), has been recognized for a long time.  However, the connection between this defect and the progressive lung disease/inflammation has remained uncertain.

Now, new animal models have provided a wealth of information that closes the knowledge gap.

Here are the key points:

  • CF affects the lungs very early: Bronchiectasis is present in nearly one in three children with CF by 3 years of age and CT scans are abnormal in most babies with CF as early as 3 months of age.
  • Infection precedes inflammation: “During the first hours after birth, piglets with CF show no evidence of inflammation in their airways…yet,…they fail to eradicate bacteria as well…[which] can initiate a cascade of airway inflammation and airway remodeling.”
  • There are multiple “hits” on the airways.  While many have suggested that increased sodium leads to a ‘dehydrated’ state, this does not seem to be correct.
  • More recent studies point to loss of bicarbonate secretion as a crucial factor.  This results in a reduced pH which in turn leaves the lungs more vulnerable to infection.  Lower acidity reduces the effectiveness of a “complex soup of antimicrobial peptides, proteins, and lipids in airway-surface liquid.”
  • Poor mucociliary transport, “which guards the lungs by trapping invading pathogens and particulates in mucus,” is another important “hit” on the lungs.


  • CF needs to be diagnosed early and treated early
  • Improving even one of these defects in host defenses is likely to be beneficial.
  • Animal models remain important in understanding pathophysiology.  They allow “investigating the disease at its genesis and before the onset of secondary manifestations.”

Related blog posts:

Second-Guessing Aggressive Medical Treatment in Pediatrics

An excerpt of a review of a recent study (Inflamm Bowel Dis. 2014;20:291-300.) from Healio Gastro, http://bit.ly/1njexRZ.  This study was briefly referenced at the bottom of a previous blog post (UC SUCCESS | gutsandgrowth).

Mortality and malignancy, the most serious complications of pediatric inflammatory bowel disease, were relatively rare and linked most commonly with aggressive treatment rather than the condition itself, according to recent study data.

In a multinational retrospective study, researchers surveyed all pediatric gastroenterologists in 20 European countries and Israel on cancer and/or mortality among their pediatric patients with inflammatory bowel disease (PIBD) from 2006 to 2011.

Among 44 children diagnosed with IBD (median age at diagnosis, 10 years; 26 boys), 18 cases of cancer were identified and/or 31 patients died. Twelve cancer patients had Crohn’s disease, and 19 patients who died had ulcerative colitis (UC). The most common cancers were hematopoietic tumors (n=11). Mortality was attributed to infections (n=14) and other causes, including cancer (n=5), uncontrollable disease activity related to IBD (n=4) and procedural complications (n=3).

“Cancer and mortality in PIBD are rare, but cumulative rates are not insignificant,” the researchers wrote. “…. At least six lymphomas were likely treatment-associated by virtue of their phenotype.”

Researchers said that aggressive therapy with immunosuppressants and biologics has become common among PIBD patients because their disease is often more severe than that found in adults with IBD…

“Nine out of 19 patients with UC died because of an infectious complication. These fatalities may have been prevented by earlier surgical intervention when intensified medical treatment is ineffective.”

Bottomline: Making a colectomy decision is quite difficult when medical therapies may be effective.  Recent guidelines using PUCAI scores may assist physicians in identifying medical failures more quickly.


Reporting Bias: Infections with TNF Inhibitors

A recent article (Clin Infect Dis 2013; 57: 1318-30 -thanks to Jeff Lewis for this reference) summarized the pediatric literature on infectious complications associated with tumor necrosis factor-α (TNF) inhibitors for both Juvenile Idiopathic Arthritis (JIA) and Inflammatory Bowel Disease (IBD).

In total 33 studies for JIA were included and 39 studies for IBD.  Many others were excluded due to overlapping cohorts or lack of sufficient data.

For JIA, the authors identified 296 infliximab (IFX) patients, 2465 etanercept patients, and 242 adalimumab patients.  Most infectious were mild and mainly viral etiology.  For example, 1016 upper respiratory illnesses with etanercept were reported.  However there were a significant number of more serious infections which included lower respiratory infections (n=37), cellulitis/abscess (n=15), histoplasmosis (n=2), and meningitis (n=4). Four patients had infectious fatalities.

Similarly, for IBD, most patients had mild infections.  Among 1407 IFX patients and 241 adalimumab (ADA) patients, there were 105 URIs noted.  Again, more serious infectious were noted in many.  Four fatalities were reported; 1 was due to disseminated CMV, 1 due to bacterial sepsis, and 2 were due to central line infections.

When examining this report, the question of reporting bias cannot be avoided. The various reports that were summarized included 30 prospective studies, 23 retrospective studies, and 19 various reports (case reports, case series, and FDA reports).  The composite, in my view, likely overestimates the risk of serious infections.  In addition, many of the infections may have been due to concurrent immunosuppressive therapy, but the details for this are lacking.

With regard to microbiology:

  • 5 JIA patients had tuberculosis; there were no tuberculosis cases reported in the IBD cohort
  • Varicella/zoster was the most frequent viral infection and was frequently severe.  In JIA cohort, there were 39 VZV cases (11 severe); among IBD cohort, there were 16 VZV cases (3 severe).

Bottomline: Given the frequent use of anti-TNF agents, better prospective pediatric data are needed.  In addition, careful analysis of the data is needed for better attribution; the risk for many of these infections is likely due to concurrent medications like corticosteroids.

Also Noted:

Clin Gastroenterol Hepatol 2013; 11: 826-31.  In a prospective cohort of 200 anti-TNF-naive adult patients (100 treated with IFX and 100 with ADA), the effectiveness was similar for IFX and ADA at both 1 and 2 year followup.  Improved efficacy was noted when these agents were combined with immunomodulators, though this was statistically significant for IFX. The total patient response was 63.5% at 1 year and 45% at 2 years.

Related posts:

TNF-α antagonists and infections

In our pediatric patients who receive tumor necrosis factor-α (TNF-α) antagonists, fortunately we see few infectious complications.  In older patients, infections are much more important source of morbidity.  The main TNF-α inhibitors in clinical use include infliximab, etanercept, adalimumab, and certolizumab. Two large studies help quantify this risk:

  • Grijalva CG et al. JAMA 2011; 306: 2331-39.
  • Strangeld A et al. Ann Rheum Dis 2011; 70: 1914-20.

The first study assembled retrospective cohorts between 1998-2007 with rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and psoriasis/psoriatic arthritis or ankylosing spondylitis (group 3).  This study’s acronym is SABER: Safety Assessment of Biologic Therapy. This data was compiled from 4 large US automated databases.  In total, there were 10,484 RA, 2323 IBD, and 3215 group 3 patients.  1172 serious infections were identified, mostly (53%) pneumonia or skin/soft tissue infections.  Among IBD patients, hospitalization rates were 10.91 (per 100 person-years) for TNF-α antagonists and 9.6 for comparison group.  The rates of hospitalization were similar in RA (8.16 with TNF-α antagonists) and lower in the group 3 patients (5.41 with TNF-α antagonists).   In all groups, baseline glucocorticoid use was associated with a dose-dependent increase in infections.  Overall, there was not an increase risk of hospitalizations with TNF-α antagonists compared with nonbiologic treatments.

The second cited reference examined patients from Germany with RA, enrolled in the RABBIT registry.  Data was available for 5044 patients.  There were 392 serious infections in this cohort with fewer infections noted after 3 years.  Risks for infection included age (>60), chronic lung or renal disease, history of serious infections, and treatment with glucocorticoids.  Treatment with 7.5-14mg conferred at relative risk (RR) of 2.1; treatment with ≥15mg conferred a RR of 4.7.  The rates of serious infections has an exponential change when risk factors are added together.  In Figure 3, estimated risk of serious infections for patients receiving ≥15mg  glucocorticoids along with three additional risk factors was 45% per year; with two risk factors the risk was approximately 20% and with one additional risk factor approximately 10%.

While these studies confirm significant risks of infections with biologic agents, the absolute risk is low particularly when other risk factors are not present.  In pediatric populations, glucocorticoids are the most prominent risk factor.  In addition, the risk of serious infections may be reduced by effective therapy.  In the SONIC study, serious infectious complications were less frequent in patients on combination therapy (infliximab and azathioprine) than with either monotherapy.  This result was likely due to the decreased need for glucocorticoids.

Additional references/relevant previous blogs:

  • NEJM 2010; 362: 1383. Sonic study. Combination AZA/IFX with greater efficacy. 56.8% remission in combo Rx.
  • -IBD 2008; 14: 721.  Pneumocystis jiroveci (carinii) w infliximab -review of 84 cases.  Dig Dis Sci 2007; 52: 1481-84.  PCP most likely to occur on average 3 weeks after 2nd infusion (possibly due to concommitant drug use)
  • -Gastroenterology 2008; 134: 929.  n=100 consecutive IBD patients with opportunistic infections.  Any of drugs associated w ~2.9 OR in adutls (greatest in >50yrs).  OR 14.5 when multiple immune drugs. Steroids more associated with Candida. AZA/6MP more with viral: HSV, VZV (shingles), CMV.  IFX less commonly with infections -though increased histoplasma and atypical mycobacterium
  • -Gastroenterology 2009; 136: 1182.  Review of biologics.
  • -IBD 2007; 13: 769.  Review of safety of wide range of biologics
  • Clin Gastroenterol Hepatol. 2006; 5:621-30.  TREAT registry.  Steroids but not biologics associated with increased mortality risk.
  • Only one chance to make first impression