Mean Corpuscular Volume (MCV)

Longitudinal Data

Trend Analysis

MCV has been consistently elevated above the KIMS reference range (82–92 fL) across all measurements, indicating persistent macrocytosis. Values have remained stable in the 92–97 fL range through May 2026.

June 1, 2026 escalation (transient): MCV jumped to 100 fL — the highest MCV recorded at KIMS and exceeding even the prior DDRC peak of 99.8 fL (Feb 20, 2026). This represented a +5.0 fL increase from May 27 (95 fL).

June 6, 2026 improvement: MCV decreased to 96.3 fL (−3.7 from June 1) — macrocytosis improved. The June 1 spike was likely transient and related to acute stress erythropoiesis during the nadir period. MCV 96.3 fL is still elevated above KIMS standards (82–92) but within DDRC's wider range (83–101).

Possible mechanisms for June 1 escalation:
- Azacitidine effect — cumulative dose-dependent macrocytosis is a known effect of hypomethylating agents
- Stress erythropoiesis — rapid RBC regeneration after May 17 nadir may produce larger, immature RBCs
- Folate/B12 functional deficiency — though folate was normal (>20) and B12 supplementation active via renerve, functional deficiencies can occur
- Hemodilution artifact — if Hb dropped (12.0 → 11.3) while Hct dropped less proportionately, MCV calculation (Hct/RBC) would increase

Historical context: The 2022 baseline MCVs were normal: 88 fL (Nov 2022, Jothydev's) and 87.5 fL (Sep 2022, DDRC SRL) — both normocytic. The shift to macrocytosis (97+ fL) by November 2025 correlated with AML/MDS development. The persistent and now worsening macrocytosis during treatment is multifactorial — underlying Aml (myelodysplastic changes) plus azacitidine contribution. See also Anemia, Hemoglobin, Rbc Count.