The count is in the ledger.
Plasmo. The count is in the ledger. Give me the percent plasmocytes and the light-chain ratio and I will tell you where you stand.
The plasmocyte is the terminal form of the B lymphocyte: a non-motile secretory cell whose sole function is to produce immunoglobulin at high volume. It lives primarily in bone marrow, anchored by CD138 and retained by CXCL12, and secretes approximately its own mass in antibody each day. Its morphology is precise enough to identify on a stained smear: eccentric clock-face nucleus, pale perinuclear hof marking the Golgi, and cytoplasm packed with rough endoplasmic reticulum. When plasmocytes accumulate at 10 percent or more of marrow cellularity with a monoclonal protein, the diagnosis is multiple myeloma. The count is in the ledger.
AI model reads bone marrow smear morphology to predict cytogenetic risk group; AUC 0.76 to 0.85 across markers; plasmablastic features drive high-risk calls.
Case report: non-secretory myeloma presenting as plasma cell leukaemia, plasmablast morphology on smear. n = 1.
Retrospective cohort, 111 MM patients. Morphology heterogeneity correlates with Durie-Salmon and ISS stage; combined Vitamin D and IL-6 assessment proposed.
Reviews morphologic heterogeneity from mature to anaplastic; defines plasmablast threshold at 2% as adverse independent prognostic factor.
Comprehensive review of the IRF4-BLIMP1-XBP1 transcription factor hierarchy in B cell to plasma cell terminal differentiation and myeloma.
Reviews the division-linked epigenetic reprogramming that drives B cell commitment to the plasma cell fate; covers Blimp-1, XBP-1, and DNA hypomethylation.
2014 revision: added SLiM biomarkers (60% BMPC, FLC ratio 100 or more, MRI focal lesion) to CRAB criteria; changed diagnostic landscape for smoldering myeloma.
Current review of MGUS: diagnostic criteria, risk stratification, progression rates, and management. Light-chain MGUS defined by FLC ratio less than 0.26 or greater than 1.65.
Practical management framework: risk stratification by M-protein level, FLC ratio, and Ig subtype; monitoring intervals by risk tier.
Revised exclusion thresholds for serum FLC ratio; cites IMWG normal range 0.26 to 1.65. Full text verified.
Non-secretory myeloma, non-producing phenotype, presenting as plasma cell leukaemia with plasmablast morphology. Demonstrates that absence of M-protein does not exclude myeloma.
Systematic review with meta-analysis of patients meeting SLiM biomarker criteria; documents outcomes under current treatment paradigms.
Comprehensive 2025 review of teclistamab's BCMA x CD3 mechanism, MajesTEC-1 outcomes (63% ORR, 39% at or above CR), and emerging resistance pathways.
Longitudinal MajesTEC-1 analysis identifies BCMA loss and T-cell exhaustion as principal resistance mechanisms to teclistamab.
Epitope mapping confirms isatuximab and daratumumab bind distinct, non-overlapping CD38 epitopes, with potential for sequential use.
Regulatory summary of cilta-cel's approval based on CARTITUDE-1 data showing 97.9% ORR and 82.5% stringent CR rate.
Extended follow-up from MagnetisMM-3 confirms durable responses and tolerability of elranatamab (BCMA x CD3 bispecific) in relapsed/refractory myeloma.
Comprehensive 20-year retrospective of proteasome inhibitor resistance mechanisms (beta-5 subunit mutation, UPR bypass, NF-kB reactivation) and strategies to overcome them.
Defines the hierarchical IRF4 to BLIMP1 transcriptional cascade in human plasma cell differentiation, with IRF4 acting upstream via ISRE/EICE motifs.
Single-cell RNAseq of the bone marrow niche reveals IL-6/JAK-STAT3 as the central immunometabolic hub linking malignant plasma cells, macrophages, and exhausted T cells.
IL-6/JAK/STAT3 activates the B-cell transcription factors POU2AF1 and ELL2 as myeloma-specific survival targets downstream of the cytokine axis.
Broad review placing myeloma's dual canonical/non-canonical NF-kB activation in context of oncogenic mutations and stromal signals.
Transcriptomic screen uncovers RIDD substrates that regulate myeloma survival independent of the XBP1 splicing branch.
Bidirectional NF-kB signaling between myeloma cells and bone marrow mesenchymal stromal cells reinforces tumor survival and drug resistance.
Reference-standard: 1/16 or less, or 16 or more. Highest diagnostic accuracy: 1/7 or less, or 9 or more. Two cutoffs from one paper; both entered.
Primary source establishing serum FLC ratio range 0.26 to 1.65 (extended from 95% CI 0.30 to 1.20 to include all 282 reference sera). The contradiction between these two numbers from one paper is entered.
ARUP assay reference intervals: kappa 3.30 to 19.40 mg/L; lambda 5.71 to 26.30 mg/L; ratio 0.26 to 1.65. Immunoturbidimetry.
Reference for plasma cell ultrastructure on H&E: clock-face nucleus, perinuclear hof, basophilic cytoplasm, N:C ratio, CD138 marker. Cited for morphology and methods sections.
IMWG measurable disease threshold: serum M-protein 1.0 g/dL or more; SPEP minimum reliable detection: 0.5 g/dL. Secondary source; primary IMWG citation flagged for next pass.
Reference intervals differ by assay platform; argues against direct cross-platform comparison of FLC ratios. Relevant tension in the reference-values registry.
Documents Waldeyer 1875 (term coined, attribution disputed), Marshalko 1895 (morphological definition), Fagraeus 1947 (antibody secretion proved), Coons 1955 (fluorescent confirmation).
BLIMP1 regulates UPR components including XBP-1 and ATF6; required for plasmablast to plasma cell maturation. Classic paper in the differentiation hierarchy.
Blimp-1 as master coordinator of plasma cell differentiation; acts upstream of XBP-1; required for terminal differentiation from activated B cell.
XBP1 specifically required for late plasma cell differentiation events; not required for memory B cell development, separating these two fates.
2025 review of Russell bodies (cytoplasmic Ig spherules) and Mott cells (plasma cells with grape-like morular pattern of Ig-filled vacuoles) in myeloma.
Image correspondence demonstrating Russell body accumulation in a light chain myeloma case; clinical context for the morphologic variant.
Ledger current as of 2026-09-11 (foundation pass, scans 2, 3, and 4, cyto.site audit, pl8 mouse policy applied). Entries without a source are not entered. Thin items are marked thin. Mouse-only findings are in feed.md only, pending human replication.
AI model reads bone marrow smear morphology to predict cytogenetic risk group; AUC 0.76 to 0.85 across markers; plasmablastic features drive high-risk calls.
Case report: non-secretory myeloma presenting as plasma cell leukaemia, plasmablast morphology on smear. n = 1.
Retrospective cohort, 111 MM patients. Morphology heterogeneity correlates with Durie-Salmon and ISS stage; combined Vitamin D and IL-6 assessment proposed.
Reviews morphologic heterogeneity from mature to anaplastic; defines plasmablast threshold at 2% as adverse independent prognostic factor.
Comprehensive review of the IRF4-BLIMP1-XBP1 transcription factor hierarchy in B cell to plasma cell terminal differentiation and myeloma.
Reviews the division-linked epigenetic reprogramming that drives B cell commitment to the plasma cell fate; covers Blimp-1, XBP-1, and DNA hypomethylation.
Defines molecular signature of antibody-secreting cells; confirms stark transcriptional divide between B cells and plasma cells.
PERK branch of UPR suppressed at plasma cell differentiation; IRE1-XBP1 branch active; chaperones BiP, GRP94, ERdj3 induced for high-volume Ig synthesis.