European Journal of Cardiovascular Medicine

Anemia is a global public health and clinical problem affecting nearly every specialty, and its presence often signals underlying nutritional deficiency, chronic inflammation, renal dysfunction, hemoglobinopathies, or marrow pathology.1–3 The burden is especially high in low- and middle-income settings, where nutritional iron deficiency and chronic infectious/inflammatory conditions frequently coexist.2,4 From a pathology perspective, anemia is not a single disease but a laboratory phenotype that must be interpreted in the context of red cell morphology, indices, and the patient’s clinical profile.1,5

A practical and widely accepted first step is morphological classification using mean corpuscular volume (MCV) and peripheral smear findings into microcytic hypochromic, normocytic normochromic, macrocytic, and dimorphic patterns.1 This approach narrows differential diagnoses efficiently. Microcytic hypochromic anemia commonly reflects iron deficiency anemia (IDA) or thalassemia trait; less frequently, sideroblastic anemia or lead toxicity.1,6 Normocytic normochromic anemia is typical of anemia of inflammation/chronic disease (AI/ACD), CKD, acute blood loss, or early nutritional deficiency.3,7 Macrocytic anemia suggests megaloblastic states (vitamin B12/folate deficiency), liver disease, alcohol use, hypothyroidism, or drug effects; peripheral smear (macro-ovalocytes, hypersegmented neutrophils) provides key diagnostic clues.8,9 Dimorphic anemia reflects mixed deficiencies (iron plus B12/folate), post-transfusion states, or response to therapy.1

Iron physiology and hepcidin-mediated regulation are central to understanding both IDA and AI/ACD.3,5 In IDA, depleted iron stores (low ferritin) and reduced circulating iron limit hemoglobin synthesis.6 In AI/ACD, inflammatory cytokines raise hepcidin, restricting iron egress via ferroportin and producing functional iron deficiency despite normal or elevated ferritin.3,7 This distinction is clinically critical because treatment strategies differ—IDA requires iron replacement and evaluation for sources such as gastrointestinal blood loss, whereas AI/ACD requires addressing the underlying inflammatory condition and cautious iron use when appropriate.3,6,10

Modern anemia work-up emphasizes a stepwise but comprehensive approach—CBC with indices, smear, reticulocyte response, iron studies, renal function, and directed tests (B12/folate, Hb analysis, endoscopic evaluation) based on clinicopathological suspicion.10–12 Biomarkers such as reticulocyte hemoglobin (Ret-Hb/Ret-He) can improve early detection of iron-restricted erythropoiesis and complement ferritin interpretation, particularly in inflammatory states.13–15

In tertiary care centers, patients often present with multiple comorbidities and overlapping etiologies, making clinicopathological correlation essential.12 Therefore, this study was designed to describe anemia patterns and correlate morphological types with biochemical parameters and clinical diagnoses to support high-yield diagnostic pathways in routine practice.

Hospital-based observational, cross-sectional study conducted in the Department of Pathology of a tertiary care teaching hospital over 12 months. Study population and sample size Consecutive patients referred for anemia evaluation were enrolled until n = 300. Inclusion criteria 1. Age ≥15 years. 2. Hemoglobin below reference thresholds: <13 g/dL (males), <12 g/dL (females). 3. Willingness to provide clinical history and consent for required investigations. Exclusion criteria 1. Recent blood transfusion within the previous 3 months (to avoid post-transfusion dimorphism). 2. Overt acute hemorrhage/trauma requiring emergency resuscitation. 3. Pregnancy (physiological hemodilution and separate reference pathways). 4. Known hematological malignancy on treatment. 5. Inadequate sample quality (clotted sample/hemolysis) or incomplete minimum work-up. Data collection A structured proforma captured demographics, diet pattern, menstrual history (females), bleeding history, chronic inflammatory diseases, renal disease, drug history, and symptom profile (fatigue, breathlessness, palpitations). Clinical examination findings (pallor, icterus, edema, hepatosplenomegaly) were recorded. Laboratory evaluation • CBC with RBC indices: Hb, Hct, MCV, MCH, MCHC, RDW, WBC, platelets (automated analyzer). • Peripheral blood smear: Romanowsky stain; morphology (microcytosis, hypochromia, anisopoikilocytosis), leukocyte/platelet clues, hemolysis features. • Reticulocyte count (when indicated). • Iron studies: Serum iron, TIBC, transferrin saturation, ferritin. • Biochemistry: Serum creatinine/eGFR, CRP/ESR where indicated; LFT/TSH if clinically suspected. • Vitamin assays: Serum vitamin B12 and folate for macrocytosis/dimorphism or suggestive smear. • Hb analysis: Hb electrophoresis/HPLC for microcytosis with normal ferritin or family history (suspected hemoglobinopathy). Definitions (operational) • Microcytic: MCV <80 fL; Normocytic: 80–100 fL; Macrocytic: >100 fL. • IDA: low ferritin and/or low transferrin saturation with compatible morphology. • AI/ACD: normal/high ferritin with low serum iron and low/normal TIBC with inflammatory context. Megaloblastic: macrocytosis with low B12/folate and/or classic smear findings. • CKD anemia: reduced eGFR with normocytic pattern and exclusion of other causes. Statistical analysis Data expressed as mean ± SD for continuous variables and n (%) for categorical variables. Associations between morphology and etiological categories were assessed using chi-square test; p <0.05 considered significant.

Table 1. Demographic profile of study population (n=300)

Anemia evaluation was most common in adults ≥50 years (40%). Female predominance (58%) suggests contribution from nutritional deficiency and menstrual blood loss in addition to chronic disease causes.

Table 2. Severity grading of anemia

Nearly half had mild anemia, but a substantial proportion (42%) had moderate anemia—supporting the need for etiologic work-up rather than empiric supplementation alone. Severe anemia (12%) represents high-risk patients needing urgent evaluation.

Table 3. Morphological pattern of anemia (CBC indices + smear)

Microcytic hypochromic anemia was the dominant pattern, indicating likely iron deficiency/thalassemia spectrum. Normocytic anemia was also common, consistent with inflammation/CKD patterns seen in tertiary care.

Table 4. Etiological distribution of anemia

IDA remained the leading cause (44%), but AI/ACD formed one-fourth of cases—highlighting the dual burden of nutritional deficiency and chronic inflammation in tertiary care practice.3,6,7

Table 5. Clinicopathological correlation: morphology vs etiology

Morphology provided strong etiologic direction. Microcytosis aligned predominantly with IDA, while normocytic anemia correlated with inflammation/renal disease. Macrocytosis was largely megaloblastic, supporting smear-guided vitamin testing.8,9

Table 6. Biochemical profile by major etiologies (mean ± SD)

IDA showed classic low ferritin and low transferrin saturation. AI/ACD showed relatively preserved/high ferritin with low iron availability, consistent with iron sequestration. Megaloblastic anemia demonstrated macrocytosis and low B12 levels, supporting targeted vitamin replacement.3,6–9

This tertiary care clinicopathological study demonstrates that microcytic hypochromic anemia remains the predominant morphological pattern, with iron deficiency anemia (IDA) as the leading etiology, followed by anemia of inflammation/chronic disease (AI/ACD). These findings align with contemporary understanding that anemia burden is driven by a mixture of nutritional deficiencies and chronic disease states, particularly in settings where infections, inflammatory disorders, renal disease, and malignancy are prevalent.2,4,6

Morphological typing using MCV and peripheral smear provided high diagnostic yield. Nearly half of cases were microcytic, and most of these correlated with low ferritin and low transferrin saturation—consistent with IDA physiology where depleted iron stores limit hemoglobin synthesis.6 The importance of identifying the underlying source of iron loss or deficiency is emphasized in major guidance documents recommending evaluation for gastrointestinal blood loss (especially in men and postmenopausal women) and targeted testing rather than empiric prolonged iron therapy without diagnosis.10,16 In our cohort, the marked elevation of RDW in IDA supported anisocytosis due to mixed older normal and newer microcytic erythrocytes, a routinely available clue that helps differentiate IDA from thalassemia trait in resource-limited contexts.1,6

Normocytic normochromic anemia constituted over one-third of cases and most frequently correlated with AI/ACD and CKD. Current mechanistic models attribute AI/ACD to inflammation-driven hepcidin upregulation, ferroportin downregulation, iron sequestration in macrophages, and blunted erythropoietin response—producing functional iron deficiency with normal or high ferritin.3,7 This pattern was reflected in our AI/ACD group showing comparatively higher ferritin with reduced transferrin saturation. Such differentiation is clinically relevant because iron indices may be misleading if ferritin is interpreted without inflammatory context.3,5,7

Macrocytic anemia (12%) was largely megaloblastic, consistent with published clinical pathways emphasizing the role of smear findings (macro-ovalocytes, hypersegmented neutrophils) and vitamin assays to confirm B12/folate deficiency.8,9 Given that mixed deficiencies are not uncommon in tertiary care, the presence of dimorphic anemia—though small—highlights the need to consider dual pathology, especially in patients with malnutrition, chronic illness, or prior partial therapy.12

Recent evidence supports the use of reticulocyte hemoglobin measures (Ret-He/Ret-Hb) as markers of iron-restricted erythropoiesis, offering earlier detection than conventional indices and aiding interpretation when ferritin is confounded by inflammation.13–15 Incorporating these parameters where available can improve diagnostic precision and reduce delays in treatment initiation.

Overall, our findings reinforce the value of a structured anemia work-up starting with morphology, then applying targeted biochemical and etiological testing—a strategy supported by contemporary diagnostic frameworks.12 This approach enables efficient etiological classification and focused management in routine tertiary care practice.

1. Microcytic hypochromic anemia was the commonest morphological pattern, and IDA was the leading etiology. 2. Normocytic anemia was strongly associated with AI/ACD and CKD, emphasizing the need for inflammatory and renal assessment in tertiary care. 3. Macrocytosis largely represented megaloblastic anemia, underlining the importance of smear-guided vitamin testing. 4. A morphology-first clinicopathological algorithm with directed biochemical tests provides a practical, high-yield strategy for anemia evaluation.

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