Although the implications of lymphopenia in adults with inflammatory bowel disease (IBD) have been explored, there is little data in pediatrics. Studies suggest lymphopenia in adults with IBD may be associated with disease severity, duration of disease, post-operative recurrence risk and effects of therapy (1, 2, 3). This study aims to calculate the frequency of lymphopenia at time of diagnosis in pediatric IBD patients and determine if it has prognostic value for disease severity.Methods:
We conducted an IRB-approved retrospective chart review of patients ≤18 years old diagnosed with IBD at our institution from 2000 to 2015. Inclusion criteria included a diagnosis of Crohn Disease (CD) or Ulcerative Colitis (UC) and laboratory data drawn prior to treatment. Lymphopenia was defined as an absolute lymphocyte count ≤1500 cells/mm3. A comparison of the clinical features included age at diagnosis and laboratory studies (ESR, CRP, hemoglobin, albumin), while disease severity was determined based on Paris classification, presence of perianal disease, intrabdominal abscess, need for surgical intervention, and escalation of therapy to anti tumor necrosis factor agents.Results:
A total of 199 patients fulfilled criteria (53 UC, 146 CD). The percentage of CD and UC patients with lymphopenia was 35% (51 of 146) and 28% (15 of 53) respectively (P = 0.380). In the UC cohort, lymphopenia was not a predictor of disease severity. In the CD cohort, lymphopenic patients were more likely to be older at diagnosis (P = 0.040), have lower hemoglobin levels (P = 0.010) and have higher inflammatory markers (CRP, P < 0.001; ESR, P = 0.003). Although there was a trend towards lymphopenic CD patients requiring more surgery (P = 0.188) and intra-abdominal abscess (P = 0.158), neither of these was statistically significant.Conclusions:
To our knowledge, no one has ever evaluated the relationship of lymphopenia at diagnosis in pediatric patients with IBD and disease severity. Lymphopenia occurs in more than one-quarter of pediatric patients with IBD. Although lymphopenia is not a marker of disease severity in ulcerative colitis, there is a signal suggesting lymphopenic pediatric patients with Crohn Disease may be more likely to have intra-abdominal abscess or require surgery. Larger studies could help tease out the importance of lymphopenia at diagnosis in pediatric patients with IBD, noting in particular if those patients are more likely to respond to white blood cell trafficking agents, like the anti-integrin monoclonal antibodies (4).