A Novel Marker for Screening Paroxysmal Nocturnal Hemoglobinuria Using Routine Complete Blood Count and Cell Population Data

BACKGROUND: Final diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) may take years demanding a quick diagnosis measure. We used the facts that PNH cells are damaged in acid, and reagents for measuring reticulocytes in Coulter DxH800 (Beckman Coulter, USA) are weakly acidic and hypotonic, to create a new PNH screening marker. METHODS: We analyzed 979 complete blood counts (CBC) data from 963 patients including 57 data from 44 PNH patients. Standard criteria for PNH assay for population selection were followed: flow cytometry for CD55 and CD59 on red blood cells (RBCs) to a detection level of 1%; and fluorescent aerolysin, CD24 and CD15 in granulocytes to 0.1%. Twenty-four PNH minor clone-positive samples (minor-PNH+) were taken, in which the clone population was <5% of RBCs and/or granulocytes. Excluding PNH and minor-PNH+ patients, the population was divided into anemia, malignancy, infection, and normal groups. Parameters exhibiting a distinct demarcation between PNH and non-PNH groups were identified, and each parameter cutoff value was sought that includes the maximum [minimum] number of PNH [non-PNH] patients. RESULTS: Cutoff values for 5 selected CBC parameters (MRV, RDWR, MSCV, MN-AL2-NRET, and IRF) were determined. Positive rates were: PNH (86.0%), minor-PNH+ (33.3%), others (5.0%), anemia (13.4%), malignancy (5.3%), infection (3.7%), normal (0.0%); within anemia group, aplastic anemia (40.0%), immune hemolytic anemia (11.1%), iron deficiency anemia (1.6%). Sensitivity (86.0%), specificity (95.0%), PPV (52.1%), and NPV (99.1%) were achieved in PNH screening. CONCLUSION: A new PNH screening marker is proposed with 95% specificity and 86% sensitivity. The flag identifies PNH patients, reducing time to final diagnosis by flow cytometry.

Clinically unsuspected Hodgkin's lymphoma diagnosed primarily from bone marrow trephine biopsy: report of six cases.

Bone marrow may be the initial or rarely the only site of involvement in Hodgkin's lymphoma. A high index of suspicion is required to pick up the histopathological changes of Hodgkin's lesions in the bone marrow like necrosis, presence of Reed-Sternberg cell or its variant in a polymorphic background infiltrate, focal fibrosis and myxoid change especially in the absence of classical clinical picture. Bone marrow with immunohistochemistry has a valuable role in the staging and in the diagnosis of primary medullary Hodgkin's lymphoma. B-symptoms may easily masquerade as an infectious process as in all our cases the patients had fever as a presenting feature, in four of them tuberculosis was suspected clinically and two had received antitubercular therapy elsewhere. We report six human immunodeficiency virus-negative patients diagnosed over a period of 5 years in which the initial diagnosis of Hodgkin's lymphoma was suggested from bone marrow histology.

Interfollicular Hodgkin's disease: an uncommon pattern that may cause diagnostic difficulty.

Interfollicular Hodgkin's Disease is characterised by reactive follicular hyperplasia with involvement of the interfollicular area of lymph node by Hodgkin's lymphoma. It represents a peculiar pattern of focal involvement of lymph node and does not constitute a classical subtype. Its importance rests in the fact that it can be misinterpreted as one of the many causes of reactive hyperplasia of lymph node and not as Hodgkin's disease. Eleven cases of interfollicular Hodgkin's disease were diagnosed in a period of five years. Majority of the patients were less than twenty years and all had localised lymphadenopathy. Lymph node biopsy showed follicular hyperplasia with expanded interfollicular area. Careful search of the interfollicular area showed infiltration by inflammatory cells and scattered Reed-Sternberg and Hodgkin's cells. Immunohistochemistry with CD 15 and CD 30 highlighted the atypical cells. This report emphasises on the problems in diagnosis of interfollicular Hodgkin's disease.

Mediastinal Castleman's disease complicated by follicular dendritic cell tumour.

We describe a rare case of follicular dendritic cell tumour which had arisen over the background of hyaline vascular type of Castleman's disease at the mediastinal location. Constellation of histology and immunohistochemistry using CD21 antibody and non-reactivity to CD15, CD30, cytokeratin and epithelial membrane antigen helped us diagnose this case. The literature is reviewed, specially with reference to the genesis of follicular dendritic cell neoplasm at the backdrop of Castleman's disease and its clinical relevance.