Clinico-hematological Analysis of Pancytopenia in Adults – A Two Year Prospective Study

Introduction Pancytopenia is a disorder in which all three major formed elements of blood (red blood cells, white blood cells and platelets) are decreased than normal. It is a common clinical problem with an extensive differential diagnosis. The pattern of diseases leading to pancytopenia may vary in different population groups with their differences in age, nutritional status and prevalence of infection. [1] Thorough physical examination, clinical history and peripheral blood picture can provide valuable information in diagnosing pancytopenia. Studies done in India stress the importance of megaloblastic anemia followed by aplastic anemia as being the major causes of pancytopenia.[2],[3]


Introduction
Pancytopenia is a disorder in which all three major formed elements of blood (red blood cells, white blood cells and platelets) are decreased than normal. It is a common clinical problem with an extensive differential diagnosis. The pattern of diseases leading to pancytopenia may vary in different population groups with their differences in age, nutritional status and prevalence of infection. [1] Thorough physical examination, clinical history and peripheral blood picture can provide valuable information in diagnosing pancytopenia. Studies done in India stress the importance of megaloblastic anemia followed by aplastic anemia as being the major causes of pancytopenia. [2], [3]

Material and Methods
A prospective study was carried out over a period of 2 years in MGM Medical College and Hospital, Kamothe, Navi Mumbai. Ethical committee approval was obtained prior to the commencement of the study.
Patients ≥15yrs and both genders were included. Clinical history was obtained along with hematological investigations and peripheral smear examination was performed. A total of 226 cases were selected based on the criteria: Haemoglobin: <10gm/dl, total leucocyte count: <4000/cmm and platelet count: < one lakh/cmm. [4], [5], [6], [7], [8] Patients on chemotherapy or radiotherapy, diagnosed cases of pancytopenia and recently received blood transfusions were excluded from this study.

Discussion
Pancytopenia is a common haematological finding where red blood cells, white blood cells and platelets are decreased below their normal lower limit leading to simultaneous presence of anemia, leucopenia and thrombocytopenia.

Causes of pancytopenia:
The causes of pancytopenia in order of decreasing frequency were malaria (50%), megaloblastic anemia ( Malaria was the commonest cause of pancytopenia which was consistent with the finding of Hamid et al. [12] and Tareen et al. [18] . Studies done by Parmar et al. [19] and Thakkar et al. [11] showed malaria as second most common cause of pancytopenia. Out of 113 cases, 65 were males and 48 females. Tareen et al. [18] in their study also showed male preponderance with 34 males and 19 females. Maximum cases were seen in the age group of 15-25 years (45 cases) followed by 26-35 years (26 cases) and 36-45 years (14 cases). Hamid et al. [12] and Tareen et al. [18] observed 16-30 years and > 40 years of age group being commonly affected by malaria.
On peripheral smear examination, there were 65 cases of P. vivax, 31 cases of mixed malaria and 17 cases of P. falciparum. Pancytopenia can occur in P. vivax infection secondary to microangiopathic hemolytic anemia. A report from India revaled that pancytopenia is a atypical manifestation of P. vivax which occurs in only 0.9%. [20] It has been recently reported that both non-immunological destruction and immune mechanism involving specific platelet-associated IgG antibodies that bind directly to malarial antigen in the platelets can lead to lysis of platelets. [21] Malaria cases showed Hb in the range of 3.7-9.9 g/dL, TLC: 700-3980/cmm and platelet count: 12,000-98,000/ cmm. Both thick and thin smears showed presence of ring forms, trophozoites, mature schizonts of P. vivax and in P. falciparum ring forms and gametocytes were seen. In mixed malaria, combined features of P. falciparum and P. vivax were seen. P. falciparum malaria may cause pancytopenia as a result of direct bone marrow invasion by a parasite, immune hemolysis, DIC, hypersplenism, bone marrow necrosis or hemophagocytosis. [22] Rapid malarial antigen (RMA) test showed positivity for same types of malaria parasite as seen on peripheral smear. Apart from geographic heterogeneity, seasonal variations also influence the prevalence of malaria. The increase is particularly seen in P. falciparum. [23] Megaloblastic anemia (18.6%) was the second common cause of pancytopenia which coincides with studies done by Niazi et al. [7] (24.7%) and Soma et al. [5] (21.7%). In various studies, the incidence varied from 3.6% to 74%. The variation of incidence of megaloblastic anemia depends on the status of the nutritional anemia in that particular region of the study. [24] All cases in our study showed low levels of serum vitamin B12.

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Clinico-hematological analysis of pancytopenia in adults -A two year prospective study Annals of Pathology and Laboratory Medicine, Vol. 5, Issue 2, February, 2018 The commonest age group affected was 15-25 years, which was consistent with the findings observed by Anita et al. [1] In present study, males (78.6%) were affected more than females (21.4%), the male to female ratio being 3.66:1 which is comparable to the ratio (2.7:1) noted by Sweta et al. [14] We observed weakness (95.2%), fever (38.1%) and dyspnea (33.3%) as most common presenting complaints. Sweta et al. [14] observed dyspnea (54%) and fever (43%) as common presenting complaints. In this study, no case presented with bleeding tendencies. Memon et al. [25] observed pallor with varying degree of skin and mucosal bleedings in megaloblastic anemia. The most common clinical sign was pallor (97.6%) followed by hepatomegaly (23.8%), splenomegaly (21.4%) and lymphadenopathy (2.4%) which was similar to the findings of Khunger et al. [8] Megaloblastic anemia cases showed haemoglobin in the range of 2.9 to 9.6gm/dL, TLC: 1300 to 3990 cells/cmm and platelet count: 8,000 to 94,000/cmm. Amongst 42 cases, 40 cases showed increased MCV and 2 cases normal MCV.
Dengue (18.1%) was the third common cause of pancytopenia with 24 cases of males and 17 cases of females showing male to female ratio of 1.4:1. Ghosh et al. [26] also showed male preponderance with male to female ratio of 2.1:1. The incidence in other studies was low and varied from 0.9% to 4% which is in sharp contrast to our study. The most common age group affected was 26-35 years followed by 36-45 years and 15-25 years. The age group affected in the studies done by Santra et al. [22] and Ghosh et al. [26] were 13-30 years and 21-30 years respectively. The most common presenting complaints were weakness (92.7%), fever (90.2%), dyspnea (24.4%) and bleeding tendencies (19.5%). The most common clinical sign was pallor (100%) followed by hepatomegaly (80.5%) and splenomegaly (22%). Study done by Ghosh et al. [26] reported fever as the commonest presenting complaint along with rashes, joint pains and myalgia.
Dengue cases showed Hb in the range of 3.1-9.9 g/dL, TLC: 0.6-3.84 cells/cmm and platelet count: 4000-98,000/ cmm. Anisopoikilocytosis was seen in 26 cases, reactive lymphocytes in 30 cases and relative lymphocytosis was seen in all cases. Azin et al. [28] also noted lymphocytosis as a common finding with presence of atypical lymphocytes, bleeding and transient bone marrow suppression. Out of 41 cases, 6 cases also had megaloblastic anemia. All cases were reactive on rapid solid phase immunochromatographic card test. The epidemiology of dengue fever in the Indian subcontinent has been very complex and has changed over almost past six decades in terms of prevalent strains, affected geographical locations and severity of disease. [4] The Maharashtra State, as a whole, saw a 47% rise in dengue cases in 2012 with second highest number of deaths after Tamil Nadu. The incidence of dengue was found to be 17.95% in Kamothe, Navi Mumbai. [5] Malaria and dengue fever are both endemic in India with active transmission being reported for many years. Thus, there is a possibility of co-existing malaria and dengue infection in the same patient. [28] 4 cases of dengue were simultaneously positive for P. vivax (2 cases), P. falciparum (1case) and mixed malaria (1case). Coinfection can be more severe than single infection with severe thrombocytopenia and anemia. Failure to recognise malaria and dengue co-infection would delay proper treatment and result in increase morbidity and mortality. [28] Hypersplenism (7.1%) was the fourth common cause of pancytopenia. The incidence in other studies varied from 0.9% to 28%. In studies done by Jain et al. [10] , Hamid et al. [12] and Thakkar et al. [11] it was first, second and third common cause of pancytopenia respectively.
Iron deficiency anemia (2.7%) was the fifth common cause of pancytopenia. In other studies, the incidence ranged from 1.3% to 13%. Anita et al. [1] and Ishtiaq et al. [13] showed IDA as the second and fourth common cause of pancytopenia respectively. Iron studies were done in all cases for confirmation. Peripheral smear examination revealed microcytic hypochromic blood picture. Bone marrow aspiration showed hypercellular marrow with altered M:E ratio, increased erythropoiesis showing micronormoblasts. Myelopoiesis and megakaryopoiesis were normal.
In present study, septicemia accounted for 2.2% whereas in other studies varied from 2.5% to 11.3%. Blood cultures were performed in all the cases to find out the causative organisms.
HIV infection was an uncommon cause with an incidence of 1.8%. In other studies, the incidence varied from 1% to 12%. Savage et al . [29] observed AIDS as the fourth common cause of pancytopenia. [29] HIV infection and overwhelming bacterial infections are known to cause various hematological manifestations including pancytopenia. [10] The hematological abnormalities may be the first clinico- Tuberculosis is a common major public health problem in developing countries like India. Tuberculosis (1.8%) was an uncommon cause in our study. The incidence in other studies ranged from 0.5% to 16.7%. Tareen et al. [18] reported tuberculosis as the third common cause of pancytopenia. Cases with unexplained pyrexia, weight loss and pancytopenia should be investigated for Tuberculosis. [10] We show 3 cases of Pulmonary tuberculosis and one case of disseminated tuberculosis. Disseminated tuberculosis is known to cause pancytopenia but there are reports of pulmonary tuberculosis too causing pancytopenia. [10] The studies conducted by Ishtiaq et al. [13] , Tilak et al. [17] and Santra et al. [22] showed an incidence of 3%, 0.5% and 0.9% of disseminated tuberculosis respectively.
Aplastic anemia contributed to 1.3% which is in contrast to the findings observed by other authors where aplastic anemia was the most common cause of pancytopenia. Few studies have also reported low incidence of aplastic anemia. [1]& [24] Bone marrow aspiration showed hypoplastic marrow.
Leptospirosis was a rare cause of pancytopenia with an incidence of 0.9% and has been scarcely mentioned in the literature. They presented with fever, weakness, bleeding tendencies and pallor. The diagnosis of leptospirosis was made by immunochromatographic card test.
Dimorphic anemia showed a low incidence (0.9%) as compared to other studies where it ranged from 1.88% to 20%. All cases showed low levels of serum B12 and serum ferritin. Bone marrow were hyperceullar with micronormoblastic and megaloblastic erythropoiesis.
Myelodysplastic syndrome was one of the least common causes of pancytopenia accounting for 0.4%. The incidence in other studies ranged from 0.4% to 5.6%. Ishtiaq et al. [13] showed an incidence of 5%.
Dyskeratosis congenita (DC) was a very rare cause of pancytopenia with an incidence of 0.4%. This is in contrast to the studies reviewed in literature, wherein no case of DC causing pancytopenia has been mentioned. However, there are few case reports on DC. We encountered a case of 20year old male, resident of Maharashtra came with fever, weight loss, weakness and dyspnea with no significant family history. He presented with pallor, reticular hypopigmentation and hyperpigmentation of the skin, dystrophic nails, graying of hair and oral leukoplakia.
There was severe anemia with haemoglobin of 4.2 g/dl, TLC of 1150/cmm and platelet count of 24000/cmm. Bone marrow aspiration revealed a hypoplastic picture with reduction in all three cell lineages and relative increase in plasma cells and few lymphocytes. Genetic studies showed confirmation of mutation in DKC1 gene.

Conclusion
Pancytopenia is a common haematological problem encountered in clinical practice. Malaria was the most common cause of pancytopenia followed by megaloblastic anemia and dengue. The less common causes included hypersplenism, iron deficiency anemia, septicemia, AIDS, tuberculosis, aplastic anemia, MDS, dimorphic anemia, leptospirosis and dyskeratosis congenita. Detailed clinical history and meticulous physical examination along with baseline haematological investigations helps in early diagnosis and thus avoiding battery of unnecessary investigations while evaluating a pancytopenic patient.