Arch Dis Child 2000;83:165–169 165

An unusual concurrence of graft versus host Arch Dis Child: first published as 10.1136/adc.83.2.165 on 1 August 2000. Downloaded from disease caused by engraftment of maternal lymphocytes with DiGeorge anomaly

Javier G Ocejo-Vinyals, María-José Lozano, Pablo Sánchez-Velasco, Juan Escribano de Diego, Jesús E Paz-Miguel, Francisco Leyva-Cobián

Abstract At 1 month of age she was hospitalised with We describe a girl with DiGeorge anomaly generalised seborrhoeic dermatitis, diarrhoea, and normal cytogenetic and molecular suppurative otitis, and cutaneous candidiasis. studies, whose clinical course was compli- From the skin and ear exudates, Staphylococcus cated by graft versus host disease caused aureus and Pseudomonas aeruginosa were iso- by intrauterine materno-fetal transfusion, lated. At 4–6 months of age she developed a and several immunohaematological al- desquamative associated with terations including a monoclonal gam- leucocytosis caused by (26%) and mapathy of undetermined significance high concentrations of IgE (up to 7060 IU/ml), (first IgG, which subsequently changed to enlarged lymph nodes, and bilateral bronchop- IgM). The main clinical features and neumonia. A lymph node biopsy revealed pathological findings are discussed. significant depletion with small follicles (Arch Dis Child 2000;83:165–169) lacking germinal centres. Serological screening for human immunodeficiency virus (HIV), Keywords: biclonal gammapathy; materno-fetal chimerism; graft versus host disease; DiGeorge Epstein–Barr virus (EBV), and cytomegalovi- anomaly; Omenn’s syndrome, Evans’ syndrome rus (CMV) was negative. Subsequently (age 8–10 months), she was diagnosed as having Evans’ syndrome (platelet count 4 × 109/l; red Several studies have suggested that maternal blood cell (RBC) count 2.47 × 1012/l; a positive blood cells can cross the placenta and migrate direct Coombs test; and presence of antiplate- into the fetal circulation where they may be let ). Following corticosteroid present in substantial numbers and for ex- therapy, her platelet and RBC counts returned tended periods of time (reviewed in to normal. The infectious and cutaneous Bernischke1). Primary immunodeficiencies, picture persisted despite antibiotic treatment. mainly severe combined immunodeficiency, are sometimes associated with the persistence http://adc.bmj.com/ of maternal lymphocytes causing variable degrees of graft versus host disease (GVHD).2 In a congenitally immunodeficient host, mater- nal cells which gain entry into the fetus may provoke systemic allogeneic disease, worsening the prognosis.

We describe an unusual occurrence of on September 24, 2021 by guest. Protected copyright. chimerism caused by engraftment of maternal lymphocytes in a girl with DiGeorge anomaly (DGA). GVHD in this patient was unusual because two monoclonal gammapathies of Servicio de Inmunología, Hospital undetermined significance were detected dur- Universitario ing the clinical course. “Marqués de Valdecilla”, Instituto Nacional de la Salud, Case report 39008 Santander, Spain The propositus was born at 37 weeks gestation J G Ocejo-Vinyals of normal weight. She was dysmorphic, with P Sánchez-Velasco low set, asymmetrical, and posteriorly rotated J Escribano de Diego J E Paz-Miguel ears, lateral displacement of inner canthi, anti- F Leyva-Cobián mongoloid palpebral fissures, slight facial asymmetry, a wide nasal root, micrognathia, a Servicio de Pediatría, high arched palate, a small mouth, and short Hospital Universitario philtrum (fig 1). Hearing loss was not evident. “Marqués de No thymic shadow was present on chest ray. Valdecilla” x M-J Lozano Biochemical investigations showed low serum calcium (1.34 mmol/l) and parathyroid hor- Correspondence to: mone (7 ng/l) concentrations with a normal Dr Leyva-Cobián magnesium concentration (1.06 mmol/l). email: fl[email protected] Treatment with oral calcium supplementation Accepted 24 March 2000 and á-1-calciferol was initiated. Figure 1 Clinical photograph of the patient.

www.archdischild.com 166 Ocejo-Vinyals, Lozano, Sánchez-Velasco, Escribano de Diego, E Paz-Miguel, Leyva-Cobián

Approximately six months later, serum months of unknown causes (II-10). One of the Arch Dis Child: first published as 10.1136/adc.83.2.165 on 1 August 2000. Downloaded from protein analysis and immunofixation electro- patient’s aunts was micrognathic and died of phoresis revealed a monoclonal gammapathy septicaemia at the age of 33 (II-9). The mother (IgG1, ë chain) without Bence–Jones proteinu- of the proband has three living healthy brothers ria or skeletal lesions, and with normal bone (II-2, II-5, and II-15). The patient’s grand- marrow cytology. Because of the persistence of mother (I-2), one healthy aunt (II-14), and one chronic diarrhoea, a jejunal biopsy was per- brother (born after her death) (III-13) also formed which showed evidence of villous atro- have micrognathia. A certain degree of consan- phy. Antigliadin antibodies were undetectable. guinity exists in this family: the girl’s maternal Over the next several months she had several greatgrandmothers were first cousins (data not other infectious episodes (recurrent diarrhoea shown). as well as otitis and sinusitis) of both bacterial and viral aetiology, persistent , Methods and nasal speech (attributed to velopharyngeal IMMUNOLOGICAL STUDIES insuYciency). Laboratory studies showed the Serum concentrations of immunoglobulins, presence of antinuclear antibodies (ANA) immunoelectrophoresis, and immunofixation (titres >1/1280, with a homogeneous pattern). as well as proliferative responses of peripheral By this time (24–26 months of age), the ossifi- blood mononuclear cells (PBMC) to optimal cation centre of the hyoid bone was not yet evi- amounts of phytohaemagglutinin (PHA), con- dent. A new episode of generalised exfoliative canavalin A (ConA), pokeweed mitogen erythroderma with eosinophilia appeared at (PWM), phorbol myristate acetate (PMA), and 30–32 months of age. A histopathological skin monoclonal against CD3, were per- study was performed and the findings were formed using standard methods. PBMC popu- compatible with GVHD. lations were enumerated by fluorescence acti- Eight months later, her general status vated flow cytometry with the use of deteriorated with recurrent episodes of diar- monoclonal antibodies to cell surface determi- rhoea, bronchopneumonia, and cutaneous can- nants by routine procedures. HLA-A, -B, and didiasis. Serum electrophoresis revealed a new -DR types were determined using polymerase monoclonal band (IgM, ë chain). Again, no chain reaction (PCR) with sequence specific lytic lesions were observed in radiological stud- primers (PCR-SSP) for both the girl and her ies and her bone marrow contained normal parents. Finally, consensus primers to the join- numbers of plasma cells. She died shortly ing segments and the framework region III of afterwards at the age of 42 months from multi- the variable segments of the IgH gene were organ failure, terminal respiratory insuY- used in a seminested PCR for clonality analysis of B lymphoid proliferation as previously ciency, and disseminated infections. Postmor- 3 tem pathological findings confirmed the reported. RAG1 and RAG2 genes were thymic absence and parathyroid gland hypo- screened for mutations as described previously.4

plasia as well as an aberrant right subclavian http://adc.bmj.com/ artery and mildly immature kidneys without CYTOGENETIC STUDIES, FISH, AND ANALYSIS OF genitourinary malformations. Generalised lym- phadenopathy with severe T cell depletion was POLYMORPHIC MARKERS IN 22q11 Chromosome preparations, obtained by stand- also shown. ard techniques, of suYciently high resolution The mother was mildly dysmorphic, also (800–850 bands per haploid set) were G having a short philtrum and micrognathia banded with trypsin and Leishman stain. Fluo- (II-18, fig 2). Echographic studies during preg- rescence in situ hybridisation (FISH) was per- nancy showed several placental infarcts. The on September 24, 2021 by guest. Protected copyright. formed with lymphocytes from the proband grandmother (I-2, fig 2) had three spontaneous and the parents using a digoxigenin labelled abortions (II-4, II-7, and II-11, fig 2), another cosmid DNA specific for the locus D22S75 malformed female fetus who died in utero (N25) (as control a cosmid for the locus shortly before delivery (II-12), one child who D22S39 (pH17) in 22q13.3 was used). Cos 40 died at 17 days of age as a result of abnormal (provided by M Aubry, Montreal), a cosmid development (II-1), and another who died at 5 probe containing sequences of the zinc finger region of ZNF74 gene, located at 22q11.2,5 I 12 was also tested in the patient and her parents. In order to investigate hemizygosity for chro- mosome 22q11, three highly informative mic- rosatellite DNA markers, D22S264, D22S941 II (CA 443), and D22S944 (CA N60C11), which 12 3 4 56 7 8 9101112131415161718 map within the commonly deleted region in DGA, were used for deletion detection. The PCR and electrophoretical analysis were per- formed exactly as described previously.6 Rear- III rangement of chromosome 10p was also stud- 1234 5 6 7 8 910111213 ied as previously described.7

Figure 2 Family pedigree. Arrow indicates propositus. UnaVected individuals are Results and discussion represented by open symbols (squares, circles); open diamonds indicate spontaneous CLINICAL AND GENETIC FEATURES OF DGA abortions. Individuals with evident facial anomalies (for example, micrognathia) and/or development disorders are represented by a black lower right segment, and those who died of DGA has now been redefined as a develop- infectious processes are marked with a black upper segment. mental disorder aVecting structures which

www.archdischild.com DiGeorge anomaly and graft versus host disease 167

originate embryologically from the third and TCR diversity, characterised by a significantly Arch Dis Child: first published as 10.1136/adc.83.2.165 on 1 August 2000. Downloaded from fourth pharyngeal pouches. There is consider- diminished proportion of the TCR Vâ8+ subset able variability in the defects and in the and an important expansion of the TCR Vâ5.2 spectrum of associated anomalies.89The diver- and Vâ5.3 subsets (fig 3). sity of clinical features (partial versus complete In contrast, a progressive increase in CD19+ forms) makes precise diagnostic criteria diY- cells was evident. The last phenotypic analysis cult to define.10 About 90% of patients with performed when the IgM monoclonal parapro- DGA present hemizygosity for a region of tein was detected, showed a high proportion of chromosome 22q11 which is commonly B cells mainly expresssing surface IgM deleted.589 The acronym CATCH22 syn- (CD19+, 63% and sIgM+, 69.8%; normal range drome (cardiac defects, abnormal facies, is 7–17%). The patient was routinely moni- , cleft palate, hypocalcaemia) tored for immunoglobulin concentrations. has been suggested to describe this clinical During the first six months of her life, serum spectrum of conditions, now very broad, asso- IgG and IgM concentrations were within ciated with 22q11 deletions.8–10 normal limits for her age. However, IgE was Although the clinical and pathological stud- notably raised from birth and remained high ies seemed clearly to indicate that our patient for approximately one and a half years. fulfils all the criteria for a diagnosis of DGA,9 Coinciding with the falling IgE concentration, we sought additional evidence at a genetic IgG increased progressively and concentrations level. Cytogenetic studies showed a normal reached 2.5 g/l. A monoclonal IgG ë chain was 46XX karyotype with no deletions or translo- detected on electrophoretic analysis by im- cations. No microdeletions were found at munofixation. IgA concentrations were within chromosome 22q11.2 by using D22S75 and normal range—or just below normal—on all Cos40 probes in FISH studies. In addition, the occasions. IgM concentrations were also nor- proband’s parents did not show the 22q11 mal or slightly above normal, except shortly microdelection using M51 and sc4.1 cosmid before death when a second monoclonal gam- probes (analysis kindly performed by P A In’t mapathy (IgM ë) appeared. The significance of Veld, Rotterdam). Furthermore, polymorphic this finding in our patient lies in the isotype markers for chromosome 22 did not reveal change in the monoclonal immunoglobulin, hemizygosity at this level (data not shown). from IgG to IgM; such class switching is The 10p deletion syndrome presented in cases extremely rare. Next, we evaluated the IgH with partial DGA exhibits specific phenotype gene rearrangement by a seminested PCR characteristics, particularly sensorineural hear- method but were unable to detect clonal ing loss.711 However, hearing was apparently lymphoid proliferation of B cells shortly after normal and no 10p deletions were found in our the immunofixation detection of the IgG patient. monoclonal band. However, PCR analysis of Although a molecular defect responsible for IgH rearrangements showed one band clearly this anomaly was not detected it is possible that detectable in the gel in the 80–120 bp range the presence of a chimerism (see below) could which allowed us to classify it as monoclonal. http://adc.bmj.com/ render the interpretation of studies with highly This coincided with the appearance of the IgM polymorphic markers more diYcult. Maternal monoclonal band and the existence of a high origin of the defect was strongly suspected proportion of sIgM+ B cells (fig 4). We did not because of the family history: multiple sponta- study whether maternal cells were functional in neous abortions and neonatal deaths favour the vitro, but proliferative responses to mitogens in hypothesis of a cryptic molecular defect and this patient were probably decreased as a result together with the other mildly aVected family of the low number of T lymphocytes. members (micrognathia) point to a dominantly Antibody production was tested in vivo by on September 24, 2021 by guest. Protected copyright. inherited problem which was undetected. immunisation with both pneumococcal

IMMUNOLOGICAL FOLLOW UP STUDIES 25 Analysis of peripheral blood lymphocytes on Control + + + admission, showed CD3 , CD4 , and CD8 Patient subsets to be within normal ranges. Subse- 20 quently, the T cell numbers (CD3+, TCRáâ+) gradually decreased, mainly as a result of a slow but progressive loss of CD4+ lymphocytes. 15 Despite the low number of T cells, almost all these cells (>80%) were CD45R/RO+ (normal 10

range 29–44%). T cells also showed an cells expressing “activated” phenotype (CD3+CD25+, 40% and + + + CD3 HLA-DR , 70%) (age matched normal TCR TCR V gene products (%) 5 ranges are 3–7% and 6–9%, respectively). Functional analysis revealed low T cell prolif- erative responses triggered by PHA as well as 0 Vα2 Vβ12.1Vβ8 Vβ6.7 Vβ5.3 Vβ5.2 Vβ5.1 ConA (not shown). Proliferation to CD3/TCR + or to PMA was also depressed with normal Vβ5.3 responses to PWM throughout the patient’s life Figure 3 TCR diversity analysis of patient’s T cells. (not shown). Using a panel of mAb against Patient’s peripheral mononuclear cells were analysed by flow cytometry using the indicated anti-TCR V monoclonal TCR V region gene encoded epitopes, we antibodies. Results are expressed as % of TCR expressing showed that T cells displayed a greatly reduced cells.

www.archdischild.com 168 Ocejo-Vinyals, Lozano, Sánchez-Velasco, Escribano de Diego, E Paz-Miguel, Leyva-Cobián

+ + – OTHER DIAGNOSIS RELATED CONSIDERATIONS Arch Dis Child: first published as 10.1136/adc.83.2.165 on 1 August 2000. Downloaded from C1 C2 PLN PPB1 PPB2 PPB3 NHL1 NHL2 C Skin conditions, , hepato- , failure to thrive, chronic diar- rhoea, recurrent infections, eosinophilia, in- creased IgE, and activated T cells with low proliferation are all features seen both in Omenn’s syndrome and materno-fetal GVHD.14 Some authors have reported clinico- pathological findings resembling those ob- served in GVHD which argue in favour of the Figure 4 Clonal heavy chain gene rearrangements (lanes C1+ and C2+ are DNA hypothesis that a lymphocytic chimerism extracted from the Namalwa line and DNA from the erythroleukaemia K562 cell caused by intrauterine transfusion is responsi- 15 line, respectively. The PLN lane is postmortem extracted DNA from the DGA patient’s ble for Omenn’s syndrome, but this has not lymph nodes while P represent DNA extracted from peripheral blood at three diVerent PB1–3 been shown by other authors.16 17 There are points during the clinical course. NHL1 and NHL2 indicate DNA from two unrelated patients with non-Hodgkin’s B cell lymphomas. C− represents a negative control with no reports of children with features of DGA with DNA added. or without 22q11 deletion18 19 who developed polysaccharide vaccine and tetanus toxoid. No Omenn’s syndrome but in whom no maternal response was obtained against these antigens. cells were present and patients with eczema- Similarly, specific production of antibodies tous skin lesions occurring simultaneously with against viral antigens was also negative. Al- the appearance of a restricted Vâ TCR and 20 21 though routine serological studies did not without materno-fetal chimerism. Thymic detect antibodies to EBV, CMV, and HIV anti- defects, including those of DGA, may have a gens, a postmortem search for DNA sequences role in the mechanism contributing to the in diVerent tissues revealed the presence of restricted T cell repertoire seen in Omenn’s 22 EBV DNA sequences in spleen and lymph syndrome. Consequently, we also considered nodes as well as in a sample of frozen PBMC the possibility of Omenn’s syndrome because (not shown) but not in several other tissues of the clinical features (diarrhoea, failure to tested (jejunal tissue, lung, skin). CMV and thrive, several episodes of generalised erythro- HIV were negative by PCR studies. This has derma, eosinophilia, liver, spleen and lymph been recently reported in two patients with node enlargement, together with repeated DGA who died of an associated B cell infections)15–17 23–25 and certain immunological lymphoma.12 13 In both cases malignant cells features (activated T cells with low proliferative expressed EBV. The high number of oligo- response and restricted heterogeneity of TCR clonal B cells observed in our patient could be diversity) present in our patient. However, to related to an EBV driven expansion of these our knowledge, Omenn’s syndrome could be cells. However, we could not show histopatho- ruled out in this case by because: (1) RAG1 and logical evidence of malignancy on postmortem RAG2 mutations were not detected in our patient (not shown); (2) increased percentages examination. http://adc.bmj.com/ of B cells were present throughout the life of our patient; and (3) as stated, the presence of DEMONSTRATION OF MATERNO-FETAL CHIMERISM maternal cells in the patient was unequivocally Despite the patient’s clinical and pathological shown, a fact that could explain the Omenn’s findings indicating DGA, many other abnor- syndrome like features. malities seen in our patient, such as jejunal vil- lous atrophy, exfoliative erythroderma, Evans’ syndrome, monoclonal gammapathy, B cell CONCLUDING REMARKS on September 24, 2021 by guest. Protected copyright. proliferation, and antinuclear antibodies could DGA is still an enigma.26 This case report is the be better explained by a chronic semiallogeneic first, to our knowledge, which presents the interaction between maternal lymphocytes and simultaneous occurrence of severe GVHD, recipient cells. In addition, the immunological including Evans’ syndrome, two monoclonal alterations found (high IgE, restricted gammopathies of undetermined signifi- heterogeneity of TCR diversity, low prolifera- cance,27 28 and other immunological dysfunc- tive response of PBMC to mitogens) could be tions in DGA. The early ocurrence of GVHD also explained by GVHD. This could be caused probably resulted in chronic allogeneic stimu- by transplacental passage of maternal lym- lation. This, together with the activation of phocytes as shown by the presence of maternal residual T cell clones and lack of physiological DNA in the patient’s tissues by HLA typing of programmed cell death in the thymus are the family (table 1). These results clearly indi- linked processes which could trigger autoim- cated a maternally derived cell engraftment in mune manifestations (Evans’ syndrome, the patient. ANA). The immunoregulatory imbalance characteristic of DGA together with the Table 1 Demonstration of materno-fetal chimerism by HLA typing evidence of transplacental passage of maternal HLA loci* T cells could explain this varied clinical picture. In addition, recurrent infections in- A B DRB1 DRB4 DRB5 cluding EBV could have contributed to her Father (II-17) 1/11 60/51 15/4 53 51 grave clinical evolution. This girl could be Mother (II-18) 1/31 18/39 1/4 53 51 included in the small group of patients in which Patient (III-12) 1/31/1 18/39/51 1/15/4 53 51/51 neither FISH nor PCR analysis of polymorphic *High molecular weight DNA was isolated from lymph node cells (patient) and peripheral blood markers detect chromosome deletions. This lymphocytes (both the patient and her parents); HLA typing was performed using PCR-SSP. does not rule out the existence of undetected

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14 Appleton AL, Curtis A, Wilkes J, .DiVerentiation of smaller deletions or point mutations within et al Arch Dis Child: first published as 10.1136/adc.83.2.165 on 1 August 2000. Downloaded from materno-foetal GVHD from Omenn’s syndrome in pre- DGA critical region genes. BMT patients with severe combined immunodeficiency. Bone Marrow Transplant 1994;14:157–9. 15 Jouan H, Le Deist F, Nezelof C. Omenn’s syndrome. Patho- Critical review of the manuscript by I M Outschoorn (Instituto logic arguments in favor of a graft versus host pathogenesis: Carlos III, Madrid) is gratefully acknowledged. a report of nine cases. Hum Pathol 1987;18:1101–8. 16 Tachinani T, Koizumi S, Yachie A, et al. Immune status in 1 Bernischke K. Spontaneous chimerism in mammals. A criti- two brothers with Omenn’s syndrome: no discernible cal review. Curr Top Pathol 1970;51:1–15. chimerism on FACS analysis using a monoclonal antibody 2 Thompson LF, O’Connor RD, Bastian JF. Phenotype and specific for a maternally restricted HLA antigen. Am J function of engrafted maternal T cells in patients with Pediatr Hematol Oncol 1990;12:343–50. severe combined immunodeficiency. J Immunol 1984;133: 17 de Saint-Basile G, Le Deist F, de Villartay JP, et al. 2513–17. Restricted heterogeneity of T lymphocytes in combined 3 Lozano MD, Tierens A, Greiner TC, Wickert RS, immunodeficiency with hypereosinophilia (Omenn’s syn- Weisenburger DD, Chang WC. Clonality analysis of drome). J Clin Invest 1991;87:1352–9. B-lymphoid proliferations using the polymerase chain 18 Brooks EG, Filipovich AH, Padgett JW, et al. T-cell receptor reaction. Cancer 1996;77:1349–55. analysis in Omenn’s syndrome. Evidence for defects in 4 Villa A, Santagata S, Bozzi F, Imberti L, Notarangelo LD. gene rearrangement and assembly. Blood 1999;93:242–50. Ommen syndrome: a disorder of Rag1 and Rag2 genes. J 19 Wirt DP, Brooks EG, Vaidya S, et al. Novel T-lymphocyte Clin Immunol 1999;19:87–97. population in combined immunodeficiency with features of 5 Aubry M, Demczuk S, Desmaze C, et al. Isolation of a zinc graft-versus-host disease. N Engl J Med 1989;321:370–4. finger gene consistently deleted in DiGeorge syndrome. 20 Collard HR, Boeck A, Mc Laughlin TM, et al. Possible Hum Mol Genet 1993;2:1583–7. extrathymic development of nonfunctional T cells in a 6 Bonnet D, Cormier-Daire V, Kachaner J, et al. Microsatellite patient with complete DiGeorge syndrome. Clin Immunol DNA markers detects detect 95% of chromosome 22q11 1999;91:156–62. deletions. Am J Med Genet 1997;68:182–4. 21 Archer E, Chuang T-Y, Hong R. Severe eczema in a patient 7 Van Esch H, Groenen P, Daw S, et al. Partial DiGeorge syn- with DiGeorge’s syndrome. Cutis 1990;45:455–9. drome in two patients with a 10p rearrangement. Clin Genet 22 Notarangelo LD, Villa A, Schwarz K. RAG and RAG 1999;55:269–76. defects. Curr Opin Immunol 1999;11:435–42. 8 Hong R. The DiGeorge anomaly (CATCH 22, DiGeorge/ 23 Glover MT, Atherton DJ, Levinsky RJ. Syndrome of eryth- velocardiofacial syndrome). Semin Hematol 1998;35:282– roderma, failure to thrive and in infancy: a mani- 90. festation of immunodeficiency. Pediatrics 1988;81:66–72. 9 Hong R. The DiGeorge anomaly. In: Rosen FS, Seligmann 24 Pupo RA, Tyring SK, Raimer SS, et al. Omenn’s syndrome M, eds. Immunodeficiencies. Chur: Harwood Academic and related combined immunodeficiency syndromes: diag- Publishers, 1993:167–76. nostic considerations in infants with persistent erythro- 10 Levy-Mozziconacci A, Wernert F, Scambler P, et al. Clinical derma and failure to thrive. J Am Acad Dermatol 1991;25: and molecular study of DiGeorge sequence. Eur J Pediatr 442–6. 1994;153:813–20. 25 Baybick JH. Reticuloendotheliosis with eosinophilia 11 Van Esch H, Groenen P, Fryns JP, et al. The phenotypic (Omenn’s syndrome). Findings in fine needle aspirate of a spectrum of the 10p deletion syndrome versus the classical lymph node. Acta Cytol 1987;31:20–4. DiGeorge syndrome. Genet Couns 1999;10:59–65. 26 Parkman R, Weinberg K. DiGeorge syndrome: still an 12 Sato T, Tatsuzawa O, Koike Y, et al. B-cell lymphoma asso- enigma. J Pediatr 1998;132:3–4. ciated with DiGeorge syndrome. Eur J Pediatr 1999;609: 27 Kyle RA, Lust JA. Monoclonal gammopathies of undeter- 158. mined significance. Semin Hematol 1989;26:176–200. 13 Ramos JT, López-Laso E, Ruiz-Contreras J, et al. B cell 28 Gerritsen E, Vossen J, van Tol M, Jol-van der Zijde C, Van non-Hodgkin’s lymphoma in a girl with the DiGeorge der Weijden-Ragas R, Radl J. Monoclonal gammopathies in anomaly. Arch Dis Child 1999;81:444–5. children. J Clin Immunol 1989;9:296–305. http://adc.bmj.com/ on September 24, 2021 by guest. Protected copyright.

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