Li FY, Lenardo MJ, Chaigne-Delalande B. Loss of MAGT1 abrogates the Mg2+ flux required for T cell signaling and leads to a novel primary immunodeficiency.
Chronic EBV infection resulting in a CD20 negative lymphoproliferative disorder complicated with secondary hemophagocytosis P. Vlummens1, S. Bonte1, C. Bonroy2, V. Van Hende1, T. Kerre1 1 Department of Hematology, Ghent University Hospital, Belgium 2 Department of Clinical Biology, Ghent University Hospital, Belgium
CASE PRESENTATION A 27-year-old man presented with enlarged right axillar lymph nodes and progressive malaise, fever and night sweats. Progressive weight loss and generalized lymphadenopathy developed in the course of the following months. Routine peripheral blood analysis showed marked inflammation, microcytic anemia, normal platelet and white blood cell counts and elevated liver enzymes with normal LDH. Serologic testing was performed as the presence of and underlying EBV-infection was suspected and were compatible with a chronic active EBV infection (IgM and IgG negative) with a viral load of 43x10³ copies per µg DNA. A lymph node excision biopsy was performed showing a CD30+/ CD20- blastic B-cel population with a strongly positive EBV staining (fig 1).
As evidence for a malignancy was lacking, the diagnosis of EBV related lymphoproliferative disease was withheld.
Figure 1 : Immunohistochemical staining of the lymph node with (A) CD30 staining (40x) showing (A) CD30+ blastic population and (B) EBV in situ hybridization confirming the presence of EBV in the atypical B-cells.
Intial treatment with acyclovir and IV immunoglobulins initially resulted in a good clinical response but the EBV PCR remained positive (fig 2) and a few weeks later Bsymptoms reappeared despite continued treatment. A new biopsy of the largest PET positive axillary lymph node revealed extensive geographical necrosis surrounded by an EBV positive CD30+/CD20- blastic B-cell population, thus confirming now the presence of an EBV driven Hodgkin’s lymphoma.
FURTHER INVESTIGATIONS AND CLINICAL COURSE Bone marrow analysis was performed because of progressive pancytopenia and revealed a lymphoproliverative process and hemophagocytosis. Ferritin levels were highly elevated. Treatment was initiated with high dose corticosteroids and chemotherapy (CHOP), etoposide was added because of hemophagocytosis. Using this strategy we obtained a good partial clinical response and the EBV PCR became negative (fig 2). Evaluation after 4 cycles with PET-CT showed a complete response. As the patient had been EBV positive since several months and hemophagocytosis was present, an underlying immunodeficiency is being investigated (fig 3): • Underlying HIV/aids, hypogammaglobulinemia or SCID could be excluded. • NK analysis and leucocyte transformation tests revealed no specific abnormality. • XMEN syndrome (X-linked Mg2+ defiency characterized by uncontrolled EBV infection and neoplasia) was excluded using NKG2D expression (flowcytometry). • XLP1 (X-linked lymphoproliferative disease type I) could be excluded due to the normal NK- and T-cell function. Mutation analysis was not performed. • The presence of XLP2 is currently being evaluated through XIAP mutation analysis. Unfortunately, just before the 5th cycle of chemotherapy was planned, disease symptoms Figure 2 : Schematic overview of the treatment regimen together with EBV DNA titer (copies/µg DNA) and serum ferritin levels (µg/L). CVP : cyclophosphamide, vincristin and prednisolone. E/Eto : Etoposide. CHOP : CVP and doxorubucine. R : Rituximab. DHAP : dexamethasone, ara-C and cisplatin. IVIG : IV immunoglobulins.
re-emerged, as did hemophagocytosis and EBV viral replication. Rituximab was associated in view of B-cel depletion and after 1 cycle of R-CHOEP; treatment was changed to RDHAP chemotherapy, IV immunoglobulins, high dose corticosteroids and immunomodulating agents (neoral). This treatment is currently ongoing.
Figure 3 : (A) NK cytotoxicity Cr-release assay analysis in patient samples showing parallel NK-cel function compared with a healthy control. (B) Lymphocyte transformation test showing an equal response in patient CD4+ cells when compared with a healthy control (ConA 2µg/mL vs standard RPMI). CD8+ T-lymphocyte analysis showed a similar response (data not shown). (C) NKG2D expression in Tlymphocytes (blue) and NKT-cells shows a (slightly) lower expression when compared to normal, healthy controls (n=5, red). NK2GD expression in NK-cells however showed no difference between patient (blue) and controls (n=5, red) samples, isotype control stainings are shown in light gray. (D) NKG2D expression on iNKT (6B11+ Vb11+) showed 60% NKG2D positivity, but was not compared to healthy age/gender matched controls.
In view of the patient’s clinical evolution we plan to proceed with a allogenous stem cell transplantation. Unfortunately, the patient’s only sibling is HLA non-identical and not hapto-identical. In the hope of identifying a possible donor, an extended family search is ongoing for identifying possible haplo-identical donors, as the early results of a matched unrelated donor search also does not seem promising. As a conclusion, we want to stress the importance to look for a possible underlying immodeficiency disorder in these kind of patients, because of the implications for prognosis and further treatment. References 1. Li FY, Lenardo MJ, Chaigne-Delalande B. Loss of MAGT1 abrogates the Mg2+ flux required for T cell signaling and leads to a novel primary immunodeficiency. Magnes Res. 2011;24(3):S109-14. 2. Filipovich AH, Zhang K, Snow AL, Marsh RA. X-linked lymphoproliferative syndromes: brothers or distant cousins? Blood. 2010;116(18):3908-408.