Helicobacter pylori (H. pylori) is a Gram-negative, spiral-shaped, microaerophilic bacterium that colonizes the gastric mucosa and infects nearly half of the global population, with a significantly higher prevalence in developing countries. The infection is usually acquired during childhood and, if left untreated, may persist lifelong (1,2). While H. pylori is well recognized for its role in chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma, increasing evidence suggests that its clinical impact extends beyond the gastrointestinal tract. In recent years, growing attention has been directed toward its association with several extra-gastric manifestations, particularly hematological disorders (3,4).

Among the hematological abnormalities linked to H. pylori infection, iron deficiency anemia (IDA), vitamin B12 deficiency, and immune thrombocytopenia (ITP) are the most extensively studied. Chronic gastric inflammation caused by H. pylori impairs gastric acid secretion and reduces iron absorption, while the bacterium also competes with the host for available iron, thereby contributing to iron deficiency (5). In addition, chronic atrophic gastritis associated with persistent infection can reduce intrinsic factor secretion and impair vitamin B12 absorption, resulting in megaloblastic anemia and various neurological manifestations. These nutritional deficiencies adversely affect hematopoiesis and may lead to significant alterations in hematological parameters (6).

The relationship between H. pylori infection and thrombocytopenia has also gained considerable attention. Several mechanisms have been proposed, including molecular mimicry, autoimmune platelet destruction, and chronic immune activation induced by bacterial virulence factors such as cytotoxin-associated gene A (CagA) and vacuolating cytotoxin A (VacA). Numerous clinical studies have demonstrated improvement in platelet counts following successful eradication therapy, supporting a causal relationship between H (7). pylori infection and immune-mediated thrombocytopenia. Consequently, international guidelines recommend evaluation for H. pylori infection in selected patients presenting with unexplained thrombocytopenia or refractory iron deficiency anemia (8).

Although substantial evidence supports the association between H. pylori infection and hematological abnormalities, the magnitude and pattern of these changes vary across different populations because of geographical differences, nutritional status, bacterial virulence, socioeconomic factors, and host immune responses (9). Furthermore, limited data are available from the Indian population regarding the comprehensive hematological profile of patients with H. pylori infection. Most previous studies have focused on individual hematological parameters rather than evaluating multiple indices simultaneously (10).

Assessment of hematological parameters such as hemoglobin concentration, mean corpuscular volume (MCV), serum iron, vitamin B12, folic acid, and platelet count provides valuable insight into the systemic effects of H. pylori infection (11). Early identification of these abnormalities may facilitate timely diagnosis and appropriate eradication therapy, thereby improving patient outcomes and preventing long-term complications. A better understanding of these associations may also encourage clinicians to consider H. pylori infection as an underlying and potentially reversible cause of otherwise unexplained hematological abnormalities (12,13).

Therefore, the present study was undertaken to evaluate the hematological profile of patients infected with Helicobacter pylori and to assess the association between H. pylori infection and alterations in key hematological parameters. The findings of this study are expected to contribute to the growing body of evidence regarding the extra-gastric manifestations of H. pylori infection and support early recognition and management of its hematological consequences.

AIMS AND OBJECTIVES

Aim

• To evaluate the hematological profile of patients with Helicobacter pylori infection.

Objective

• To assess the hematological manifestations, including hemoglobin, mean corpuscular volume (MCV), serum iron, vitamin B12, folic acid, and platelet count, in patients diagnosed with Helicobacter pylori infection.

This hospital-based observational correlational study was conducted in the Department of General Medicine at Bangalore Medical College and Research Institute (BMCRI), Bengaluru. A total of 50 adult patients diagnosed with Helicobacter pylori infection and attending the outpatient and inpatient departments during the study period were included after obtaining written informed consent. Patients were selected according to predefined inclusion and exclusion criteria. Individuals with hematological disorders of known etiology, chronic liver disease, chronic kidney disease, malignancy, recent blood transfusion, pregnancy, or those receiving iron, vitamin B12, or folic acid supplementation were excluded to minimize potential confounding factors. Ethical approval for the study was obtained from the Institutional Ethics Committee before commencement of the study. All enrolled participants underwent detailed clinical evaluation, including demographic characteristics, medical history, and physical examination. The diagnosis of H. pylori infection was established using standard diagnostic methods employed at the institution. Venous blood samples were collected under aseptic precautions for laboratory investigations. Hematological parameters including hemoglobin concentration, mean corpuscular volume (MCV), platelet count, serum iron, vitamin B12, and folic acid levels were measured using standardized laboratory techniques in the central laboratory. Data were recorded using a structured proforma and maintained confidentially throughout the study. The collected data were entered into Microsoft Excel and analyzed using IBM SPSS Statistics software. Continuous variables were expressed as mean ± standard deviation, while categorical variables were presented as frequencies and percentages. Independent sample t-test was used to compare hematological parameters between groups where applicable. Correlation analysis and linear regression were performed to assess the relationship between hemoglobin levels and other hematological variables. A p-value of less than 0.05 was considered statistically significant.

Table 1. Demographic Characteristics of the Study Participants

Graph 1. Demographic Characteristics of the Study Participants

In the present study, among the study participants, the age group of 31–40 years comprised 16 (32.0%) participants, followed by the 21–30 years age group with 15 (30.0%) participants. The 41–50 years and 51–60 years age groups each included 7 (14.0%) participants. The 61–70 years age group comprised 3 (6.0%) participants, while the 10–20 years and 71–80 years age groups each comprised 1 (2.0%) participant. Regarding gender distribution, 40 (80.0%) participants were male and 10 (20.0%) participants were female.

Table 2. Hematological Profile of the Study Participants

Graph 2. Hematological Profile of the Study Participants

In the present study, the mean age of the study participants was 45.22 ± 12.72 years, with a minimum age of 16 years and a maximum age of 75 years. The mean hemoglobin level was 12.35 ± 2.02 g/dL, ranging from 7.8 to 15.5 g/dL. The mean mean corpuscular volume (MCV) was 77.89 ± 8.64 fL, with values ranging from 57.2 to 98.0 fL. The mean serum iron level was 48.73 ± 18.16 µg/dL, with a minimum of 18.0 µg/dL and a maximum of 80.0 µg/dL. The mean vitamin B12 level was 322.74 ± 109.61 pg/mL, ranging from 156 to 687 pg/mL. The mean folic acid level was 7.26 ± 2.52 ng/mL, with values ranging from 2.6 to 14.6 ng/mL. The mean platelet count was 2.78 ± 1.01 ×10⁶/mm³, with a minimum value of 0.67 ×10⁶/mm³ and a maximum value of 4.40 ×10⁶/mm³.

Table 3. Distribution of Hemoglobin Levels Among the Study Participants

Graph 3. Distribution of Hemoglobin Levels Among the Study Participants

In the present study, hemoglobin levels of 7–10 g/dL were observed in 12 (24.0%) participants, 10–12 g/dL in 14 (28.0%) participants, 12–14 g/dL in 13 (26.0%) participants, and 14–16 g/dL in 11 (22.0%) participants.

Table 4. Distribution of Mean Corpuscular Volume (MCV) Among the Study Participants

Graph 4. Distribution of Mean Corpuscular Volume (MCV) Among the Study Participants

In the present study, 8 (16.0%) participants had a mean corpuscular volume (MCV) of 60–70 fL, 18 (36.0%) participants had an MCV of 70–80 fL, 20 (40.0%) participants had an MCV of 80–90 fL, and 4 (8.0%) participants had an MCV of 90–100 fL.

Table 5. Distribution of Serum Iron Levels Among the Study Participants

Graph 5. Distribution of Serum Iron Levels Among the Study Participants

In the present study, serum iron levels of 15–30 µg/dL were observed in 7 (14.0%) participants, 30–45 µg/dL in 19 (38.0%) participants, 45–60 µg/dL in 10 (20.0%) participants, and 60–75 µg/dL in 14 (28.0%) participants.

Table 6: Distribution of Vitamin B12 Levels Among the Study Participants

Graph 6: Distribution of Vitamin B12 Levels Among the Study Participants

In the present study, vitamin B12 levels of 150–250 pg/mL were observed in 17 (34.0%) participants, 250–350 pg/mL in 11 (22.0%) participants, 350–450 pg/mL in 19 (38.0%) participants, and >450 pg/mL in 3 (6.0%) participants.

Table 7: Distribution of Folic Acid Levels Among the Study Participants

Graph 7: Distribution of Folic Acid Levels Among the Study Participants

In the present study, folic acid levels of 2–4 ng/mL were observed in 5 (10.0%) participants, 4–6 ng/mL in 13 (26.0%) participants, 6–8 ng/mL in 14 (28.0%) participants, 8–10 ng/mL in 12 (24.0%) participants, and >10 ng/mL in 6 (12.0%) participants.

Table 8. Comparison of Hematological Parameters Between Male and Female Study Participants

In the present study, the mean hemoglobin level was 12.50 ± 1.86 g/dL among males and 11.77 ± 2.05 g/dL among females (p = 0.314). The mean MCV was 78.44 ± 8.22 fL among males and 75.72 ± 10.15 fL among females (p = 0.389). The mean serum iron level was 49.86 ± 18.33 µg/dL among males and 44.20 ± 17.39 µg/dL among females (p = 0.401). The mean vitamin B12 level was 330.15 ± 112.81 pg/mL among males and 293.10 ± 96.37 pg/mL among females (p = 0.356). The mean folic acid level was 7.53 ± 2.49 ng/mL among males and 6.19 ± 2.34 ng/mL among females (p = 0.163). The mean platelet count was 2.82 ± 1.05 ×10⁶/mm³ among males and 2.59 ± 0.89 ×10⁶/mm³ among females (p = 0.541).

The present study evaluated the hematological profile of patients with Helicobacter pylori infection and demonstrated alterations in hemoglobin, mean corpuscular volume (MCV), serum iron, vitamin B12, folic acid, and platelet count, indicating that H. pylori infection is associated with significant hematological manifestations. The majority of the participants belonged to the 21–40-year age group, with males constituting 80% of the study population. A similar male predominance has been reported by Rothenbacher and Brenner (2003), who suggested that differences in lifestyle factors, environmental exposure, and healthcare-seeking behavior may contribute to the higher prevalence of H. pylori infection among males (14). The demographic findings of the present study are therefore consistent with previous epidemiological observations. The mean hemoglobin level in the present study was reduced, and a substantial proportion of patients had values suggestive of anemia. These findings are in agreement with Annibale et al. (2003), who demonstrated that chronic H. pylori infection is associated with iron deficiency anemia due to impaired iron absorption and persistent gastric inflammation (15). Similarly, Baggett et al. (2006) reported considerable variation in hemoglobin levels among H. pylori-infected individuals, emphasizing the heterogeneous hematological impact of the infection (16). The lower hemoglobin values observed in the present study support the hypothesis that chronic H. pylori infection contributes to anemia through nutritional deficiency and altered iron metabolism. The mean MCV observed in the present study indicated predominantly normocytic to microcytic red blood cell indices. These findings are comparable with those reported by Hershko and Ronson (2009), who identified H. pylori infection as an important cause of iron deficiency anemia characterized by reduced MCV resulting from impaired iron absorption (17). The predominance of lower MCV values in the present study further supports the association between H. pylori infection and iron-deficient erythropoiesis. Serum iron levels were also reduced in a considerable number of patients. Similar observations have been reported by Cardenas et al. (2006), who demonstrated significantly lower serum iron concentrations among H. pylori-infected individuals, highlighting the adverse effect of chronic infection on iron metabolism (18). The findings of the present study reinforce the importance of evaluating iron status in patients with H. pylori infection, particularly in those presenting with unexplained anemia. The present study demonstrated variable vitamin B12 and folic acid levels, with several patients showing suboptimal concentrations. These findings are consistent with those of Kaptan et al. (2000), who reported significant improvement in vitamin B12 levels following eradication of H. pylori, indicating that chronic gastritis caused by the organism interferes with vitamin B12 absorption (19). These observations support the role of H. pylori infection in causing nutritional deficiencies that may further aggravate hematological abnormalities. Platelet counts in the present study showed considerable variation, although most patients remained within the normal or lower-normal range. Comparable findings have been described by Stasi et al. (2009), who reported improvement in platelet counts following H. pylori eradication in patients with immune thrombocytopenic purpura, supporting the relationship between H. pylori infection and platelet disorders (20). Overall, the findings of the present study are consistent with previous reports and demonstrate that H. pylori infection is associated with multiple hematological abnormalities involving red blood cell indices, iron metabolism, vitamin status, and platelet count. Early diagnosis and eradication of the infection may therefore play an important role in preventing or improving these potentially reversible hematological manifestations.

The present study demonstrated that Helicobacter pylori infection is associated with significant alterations in hematological parameters, particularly hemoglobin concentration, mean corpuscular volume, serum iron, vitamin B12, folic acid, and platelet count. These findings indicate that H. pylori infection has important extra-gastric manifestations in addition to its well-established gastrointestinal effects. The observed hematological abnormalities suggest that chronic infection may contribute to nutritional deficiencies and anemia through impaired absorption and persistent gastric inflammation. Early recognition of these changes is essential, as appropriate diagnosis and eradication therapy may improve hematological status and prevent long-term complications. Therefore, clinicians should consider screening for H. pylori infection in patients presenting with unexplained anemia or other hematological abnormalities, particularly in regions with a high prevalence of infection. Further multicenter studies with larger sample sizes are recommended to better understand the underlying mechanisms and strengthen the evidence regarding the hematological impact of H. pylori infection.

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