S. Weekx PhD

Diagnosis of a gamma heavy chain disease in a 71-year-old patient with a persistent leukopenia and thrombocytopenia

SUMMARY

A 71-year-old man with persistent leukopenia and thrombocytopenia was referred to the haematology department with a suspicion of a myelodysplastic neoplasm (MDS). Upon presentation, the patient was asymptomatic. Peripheral blood analysis confirmed leukopenia and thrombocytopenia. Furthermore, IgG was elevated, while IgM, total protein and the kappa-lambda free light chain (FLC) ratio were within normal ranges. Protein electrophoresis pattern showed a prominent monoclonal peak in the gamma globulin region. The monoclonal peak was identified as IgG heavy chain without corresponding kappa or lambda light chains by immunofixation analysis. Bone marrow cytology did not provide evidence for MDS; however, an increased plasmocytosis of 8% was detected. Immunophenotyping showed the presence of 6.6% CD19+, CD38++, CD138+, CD45+ and CD56- plasma cells without cytoplasmic light chain expression. The latter was confirmed by histologic review of the bone marrow biopsy using immunohistochemical staining. Immunoglobin gene rearrangement analysis was indicative for the presence of a monoclonal B-cell or plasma cell neoplasm. On positron emission tomography (PET)-scan only a mild splenomegaly was seen. Based on all these results, the diagnosis of a gamma heavy chain disease (gHCD) was made. As the patient was asymptomatic, treatment was not indicated. Blood count and health status were unchanged at a check-up six months later. Further follow-up is performed every six months. This case report presents the diagnostic work-up of a patient with gHCD. Laboratory analysis contributing to the diagnosis of gHCD included protein electrophoresis, immunofixation, bone marrow cytology, immunophenotyping, molecular analysis and pathological examinations of a bone biopsy.

(BELG J HEMATOL 2024;15(2):49–53)

Heterophilic antibodies as the cause of a false positive malaria rapid diagnostic test: A case report

SUMMARY

A 50-year-old male patient admitted to the hospital with renal insufficiency, anaemia, monoclonal protein (IgG kappa) and uremic encephalopathy was screened for malaria due to increasing serum CRP-levels and neurological decline combined with an indistinct travel history. The malaria rapid diagnostic test (RDT) revealed a positive result; however, no malaria parasites were detected by the pathologist through microscopic evaluation of the thick and thin blood smear. Additional tests were performed to investigate potential causes of the false positive malaria RDT such as the presence of heterophilic antibodies, the monoclonal protein and rheumatoid factor. This case presented a false positive malaria RDT result due to a confirmed interference of heterophilic antibodies. The interference could be omitted using a heterophilic antibody-blocking agent.

(BELG J HEMATOL 2023;14(8):343–6)

P.24 Rare morphologic phenomena in plasma cell dyscrasia: report of two cases

A-122 IS aPTT A GOOD PREDICTOR OF RELIABLE INR IN CHRONIC INTERMITTENT HEMODIALYSIS PATIENTS?

A-142 MAJOR AUTOANTIBODY REACTIVITY SEROLOGY AND MINOR SYMPTOMS IN A SLE PATIENT : A CASE REPORT

P2.09 Prekallikrein deficiency in a 15-year-old boy with Ménière’s disease: a case report

P4.01 Retrospective study of the significance of positive DAT