Concurrent eosinophilia and IgG4-related disease in a child: A case report and review of the literature

Abstract

The current study presents the case of a 9-year-old Chinese boy who presented with eosinophilia and elevated serum levels of immunoglobulin G4 (IgG4). A bone marrow puncture identified an elevated eosinophil rate of 23% (normal range, <5%), which indicated eosinophilia. However, gene analysis, fluorescent in situ hybridization and other examinations, including bone marrow aspiration, blood routine, auto-antibody tests and parasitic and allergens screening, contradicted a diagnosis of secondary or clonal eosinophilia. Furthermore, the patient exhibited multiple lymph node swelling and a lymph biopsy strongly indicted a pathological diagnosis of IgG4-related disease (IgG4-RD). His peripheral blood flow cytometry confirmed an elevated count of plasmablasts, which is specific to IgG4-RD. The patient responded well to therapy with prednisone and remained healthy in all follow-ups. By taking all these factors into consideration, the boy was diagnosed with IgG4-RD. It is difficult to distinguish IgG4-RD from hypereosinophilic syndrome and the potential association between the two remains unclear. However, the present case study serves as a reminder that IgG4-RD may occur in children and medical professionals should not neglect this possibility.

Keywords: IgG4-related disease; child; hypereosinophilic syndrome; multiple Castleman's disease.

Figure 1.

Cervical lymph node cell infiltration. (A) Eosinophil infiltration (>80% of infiltrating cells; hematoxylin and eosin staining; magnification, ×100) and (B) CD138+ plasma cell infiltration (<20% of infiltrating cells; CD138 staining; magnification, ×100) in the tissue. (C) IgG+ and (D) IgG4+ cell infiltration in the tissue (IgG4/IgG=50%; IgG and IgG4 stained respectively; magnification, ×100). IgG, immunoglobulin G.

Figure 2.

Clinical course and concomitant EOS count, IgG4 levels and response to prednisone therapy. EOS count varied alongside IgG4 levels and both decreased following prednisone therapy. EOS, eosinophils; IgG, immuglobulin G.

Figure 3.

(A-D) Comparison of abdominal CT scans pre- and post-treatment. (A and C) Abdominal CT scans prior to prednisone treatment. (B and D) Abdominal CT scans following prednisone treatment. The abdominal lymphoma nodes in B and D were evidently diminished compared with those in A and C (white arrows and circles). CT, computed tomography.

Figure 4.

Diagnostic criteria for IgG4-related disease proposed by Umehara et al (16) in 2012. IgG, immunoglobulin G; HPF, high-powered field.

Figure 5.

Improved diagnostic criteria for IgG4-RD proposed by Nakamura et al (27). IgG4-RD, immunoglobulin G4-related disease; AIP, autoimmune pancreatitis; MCD, multiple Castleman's disease; IL, interleukin; HPF, high-powered field.