Omar M. Kattan¹, Robert S. Venick^1,2, John P. Duffy¹, Khiet D. Ngo², Joanna Colangelo¹, Yvonne Esmailian¹, E. Haddad¹, Marvin E. Ament², Suzanne V. McDiarmid¹, Ronald W. Busuttil¹, Douglas G. Farmer¹

¹Transplant Surgery, The David Geffen Scbool of Medicine at UCLA, Los Angeles, CA, United States; ²Pediatrics, The David Geffen Scbool of Medicine at UCLA, Los Angeles, CA, United States

Background: Despite recent advances in the field of intestinal transplantation (ITx), infection and rejection remain major causes of early patient and graft loss. To date there have been no studies on the impact of hypogammoglobu- linemia on early post-ITx outcomes.

Methods: A retrospective review of an IRB-approved single center database of all ITx recipients between 4/07 and 6/09 was conducted. IgA and IgG levels were recorded at the time of evaluation, pre-ITx and at weekly intervals for the first 8 weeks following ITx. Levels were normalized for age. IVIG infusion, infec- tion, rejection and survival were recorded. ANOVA was used to compare the mean immunoglobulin levels at weekly intervals and chi-square was used to evaluate the relationship of hypogammaglobulinemia, to infection, and rejec- tion.

Results: 22 patients (18 children) were transplanted at a mean age of 9.7 ± 12.9 years. The majority were male (n=12), Latino (n= 13), transplanted for gas- troschisis (n=9) and intestinal atresia (n=5) and received liver-inclusive grafts (n=18). 15 patients received IL-2 receptor antagonists as part of their induction immunosuppression while 7 received ATG. Maintenance immunosuppression included tacrolimus, MMF and prednisone. Immunoglobulin levels, IVIG require- ments infection and rejection rates are indicated in Table 1. Statistically signifi- cant variations in mean IgG levels were noted post-ITx (ANOVA, p=0.01). Such differences were not seen in IgA levels. Overall graft survival at 1/ 2 /3 /6 &12 months was 97 /93 /88 /84 & 74% respectively. Low IgG levels were not associ- ated with infection (p=0.37), however, patients with normal IgG levels for age were more likely to have biopsy proven acute cellular rejection of their trans- planted intestine (Chi-Square, p=0.02).

Conclusion: A marked decrease in both IgA and IgG levels was observed after ITx as compared to pre-ITx levels. The etiology of this is unclear but potentially related to immunotherapy. Hypogammaglobulinemia is relatively common in the early post-ITx period. Surprisingly, this was not associated with infections and may be related to our clinical practice of exogenous replacement using commercially available IVIG. Normal IgG levels are associated with risk of rejection and may implicate an antibody mediated component to rejection after ITx.