Clinical Aspects , Immunophenotypic Analysis and Survival Rate of Chronic Lymphocytic Leukaemia Patients in Erbil City , Iraq

Objectives
Chronic lymphocytic leukaemia (CLL) is characterised by an accumulation of clonal B cells in the blood, bone marrow and lymphatic tissue. This study aimed to evaluate the clinical and immunophenotypic characteristics and survival rate of CLL patients.


Methods
This retrospective study was conducted at the Nanakaly Hospital for Blood Diseases & Oncology in Erbil, Iraq, between January 2011 and December 2017. A total of 105 CLL patients were assessed to determine clinical presentation and staging, immunophenotype and survival rate.


Results
The median age of the patients was 65 years and 63.8% were male. The main clinical presentations were splenomegaly (64.8%), pallor (61.9%) and lymphadenopathy (60%). More than half of the patients presented at an advanced clinical stage according to the Rai and Binet staging systems (59.1% and 55.2%, respectively). All CLL cases expressed both cluster of differentiation (CD)19 and CD5, 67.6% had monoclonal kappa light chains and 21% expressed CD38. The five-year overall survival (OS) rate was 61.3%. The mean duration of five-year survival was 41.3 months (95% confidence interval: 36.4-46.3 months). There were no correlations between survival and sociodemographic, clinical or laboratory characteristics.


Conclusion
In comparison to the existing Western literature, Iraqi CLL patients more frequently presented with hepatosplenomegaly and at a more advanced clinical stage. In addition, the five-year OS rate was much lower.


C
hronic lymphocytic leukaemia (cll) is the most common type of leukaemia among adults in Western countries; however, it is relatively rare in Asia. 1,2It is characterised by the build-up of lymphocytes in the blood, bone marrow and lymphatic tissue.The median age at diagnosis ranges from 67-72 years and the condition is more common in males. 1,2he clinical course of CLL is highly variable, ranging from no symptoms to the rapid development of features of high-risk disease. 3Lymph node swelling is the most common presenting feature of CLL, although fever, night sweats and weight loss are sometimes seen.The most common physical findings are lymphadenopathy, splenomegaly and, less frequently, hepatomegaly. 3 diagnosis of CLL can be established via a complete blood count (CBC) showing the progressive accumulation of clonal B cells (>5,000 B lymphocytes/mL) over a period of at least three months and an immunophenotypic study demonstrating clonal lymphocytes expressing B cell markers and cluster of differentiation (CD)5. 4Both the modified Rai and Binet clinical staging systems are widely used to classify CLL patients into different prognostic groups according to the extent of lymph node involvement, enlargement of the liver and/or spleen and blood findings (i.e.anaemia and thrombocytopaenia). 5,6he median survival rate for patients with CLL ranges from 18 months to more than 10 years, depending on prognostic factors like age, gender, disease stage, performance status, lymphocyte doubling time, absolute lymphocyte count (ALC) and β-2 microglobulin serum levels. 7Furthermore, the expression of certain biological markers such as CD38 or CD49d, deletion of chromosome 17p13 and the mutation status of the immunoglobulin heavy-chain variable region, tumour protein-53 (TP53), Notch homolog 1, splicing factor-3B subunit-1 (SF3B1), baculoviral inhibitor of apoptosis protein-1 repeat-containing protein-3 (BIRC3), myeloid differentiation primary response 88 and zeta chain T cell receptorassociated protein kinase-70 (ZAP70) genes also have a prognostic impact. 8The current study aimed to assess and compare the clinical characteristics, immunophenotypic findings and survival rate of CLL patients in Erbil, Iraq, with previously reported international and regional data.

Methods
This retrospective study was carried out between January 2011 and December 2017 at the Nanakaly Hospital for Blood Diseases & Oncology, a regional referral hospital for adult and paediatric patients with benign and malignant haematology and solid oncology disorders in Erbil, Iraq.All patients attending the hospital during the study period and diagnosed with CLL as confirmed by CBC and immunophenotyping were invited to participate in the study.
The main clinical presentation and characteristics of each patient was documented, including the presence of lymphadenopathy, pallor, hepatomegaly and splenomegaly.In addition, the patients underwent a CBC and immunophenotyping study by flow cytometry using a FACSCanto II flow cytometer device (BD Biosciences, San Jose, California, USA) and/or immunohistochemistry.The laboratory analysis included a reticulocyte count, erythrocyte sedimentation rate, direct antiglobulin test (DAT), bone marrow examination, serology tests (i.e. to determine lactate dehydrogenase [LDH] levels) and liver and renal function tests.In indicated cases, patients also underwent various imaging studies, including ultrasonography of the abdomen, a chest X-ray and computed tomography.In each case, clinical stage was determined according to both the Rai and Binet staging systems. 5,6urvival rates were calculated, including the overall survival (OS) rate over the study period and the fiveyear OS rate.Data were analysed using the Statistical Package for the Social Sciences (SPSS), Version 22.0 (IBM Corp., Armonk, New York, USA).A Chi-squared test was used to compare associations between proportions.Kaplan-Meier survival curves were plotted and the log-rank Mantel-Cox test was used to compare mean survival times.A P value of ≤0.050 was considered statistically significant.
This study was approved by the Scientific and Ethical Committees of the College of Medicine, Hawler Medical University, Erbil.
The mean follow-up period was 27.7 months.A total of 34 (32.4%)patients died during the study period, of which 24 (70.6%) were male and 10 (29.4%) were female, resulting in an OS rate of 67.6%.Although survival was greater among those aged 50-59 years (90.5% versus 60-62.5% in other age groups) and among females (73.7% versus 64.2% in males), these differences were not statistically significant (P = 0.098 and 0.163, respectively).Other clinical and laboratory characteristics were also not significantly correlated with survival (P >0.050 each) [Table 4].The five-year OS rate was 61.3%.The mean duration of five-year survival was 60 months (95% confidence interval: 36.4-46.3months); however, the median survival could not be estimated and could have occurred beyond the study period.The mean duration of survival was longer among females and those aged 50-59 years old; however, these differences were not statistically significant (P = 0.185 and 0.163, respectively) [Figure 2].

Discussion
In the current study, the median age at diagnosis of CLL patients in Erbil, Iraq, was similar to that reported in neighbouring countries such as Iran and Turkey (65 years versus 60.73 and 64 years, respectively). 2,9n contrast, the median age at diagnosis in Western countries is much higher, ranging from 67-72 years old. 1,10,11However, the frequency of male CLL patients in the current study was identical to that reported in Italy (64%). 12In terms of clinical presentation, splenomegaly (64.8% versus 54%) and hepatomegaly (21.9% versus 14%) were reported more frequently in the current study compared to Western patients, while lymphadenopathy was less frequent (60% versus 87%). 3In Turkey, rates of splenomegaly, hepatomegaly and lymphadenopathy differed at 55.4%, 54.6% and 79.2%, respectively. 9In Iran, Payandeh et al. also reported varying rates of organomegaly (34%) and lymphadenopathy (38.7%). 2 The diversity of clinical presentations in CLL and correlations with ethnicity have been well documented in previous research. 13e incidence of anaemia and AIHA in the current study (78.1% and 11%, respectively) was comparable to that reported in previous research in which AIHA was documented in up to 11% of late-stage CLL patients, with positive DAT results seen in up to 15% of patients. 14In the present study, 60% of patients had thrombocytopaenia; this finding is understandable given that most patients presented at an advanced clinical stage, such as Rai stage III or IV (59.1%) or Binet stage C (55.2%).According to data from other developing countries such as Iran, Turkey and India, patients in this region are often first seen at more advanced stages (38.5%,33.3% and 41%, respectively). 2,15,16owever, in developed countries, only 10-20% of patients present at an advanced stage. 17These findings may indicate that routine CBC analysis is less frequently performed in developing countries or that hospitals in this region lack proper evaluation and management protocols or experience delays in the referral of patients with incidental lymphocytosis.It is also possible that there is a difference in the biology of the disease (e.g. in terms of such patients having a less mutated subtype of CLL). 4 In the present study, most cases expressed CD19, CD5 and CD23, with CD79b less frequently expressed; these findings are consistent with the characteristic profile of CLL disease. 18For those patients not expressing CD23-considered atypical CLL cases-other markers could help to differentiate CLL from mantle cell lymphoma, such as the negative expression of Flinder Medical Centre-7. 19Overall, CD38 expression at any level is regarded as a poor prognostic indicator; it was expressed in 21% of cases in the present study, which is comparable to the findings of Hojjat Farsangi et al. (27.6%). 20In the current study, 67.6% of patients had monoclonal kappa light chains, with 32.4% expressing lambda chains.Hojjat Fersangi et al. reported rates of expression of kappa and lambda chains to be 71.3% and 28.7%, respectively, among Iranian CLL patients. 20tamatopoulos et al. also reported similar findings in Greece. 21he OS (67.6%) in the current study was comparable to data reported from Iran (64%), although the five-year OS rate (61.3%) was higher than results from Turkey (36.5%) and India (51%). 2,22,23owever, data from Germany and the USA indicate much higher five-year relative survival rates (80.2% and 82.4%, respectively). 24The mean duration of five-year survival in the current study was 41.3 months, which is similar to data reported from Iran (38.5 months). 2 This may be related to variations in a number of patient-related characteristics, such as clinical stage at diagnosis.The reason why the five-year OS rate in the present study was lower than the overall OS is likely because patients whom were more recently diagnosed (i.e. in 2015-2017) had not yet received their five-year follow-up at the time of the analysis.
Early diagnosis plays a major role in improving survival in CLL patients. 25Other possible causes for low five-year OS rates are the lack of availability of equipment to conduct thorough cytogenetic evaluations for factors known to have a prognostic impact-such as deletions of chromosomes 11q, 13q, 17p and trisomy 12 as well as TP53, NOTCH1, SF3B1 and BIRC3 gene mutations. 8In addition, insufficient access to adequate or novel chemotherapy agents like obinutuzumab, ibrutinib, idelalisib and venetoclax as a frontline treatment or for relapsed/refractory cases may negatively affect survival. 26o significant correlations were noted between survival rates and selected sociodemographic, clinical or laboratory characteristics in the present study.These findings partially agree with those previously reported by Shvidel et al.; however, they contradict de Faria et al. 's study. 27,28The difference between these findings is probably due to variations in sample size, the lack of genetic assessment conducted in the current study and the well-known impact of ethnicity. 13n addition, data regarding CD49d and ZAP70 expression, which have a major prognostic impact on CLL patients, were not available. 8Further research is therefore recommended to evaluate these factors.

Conclusion
The median age, male-to-female ratio and clinical and immunophenotypic characteristics of Iraqi CLL patients in the current study did not differ greatly from previous regional and international data; however, patients more frequently presented at an advanced stage and had a lower five-year OS rate compared to Western populations.In addition, Iraqi patients more frequently presented with organomegaly, including hepatomegaly, although less frequently with lymphadenopathy.c o n f l i c t o f i n t e r e s t The authors declare no conflicts of interest.

f u n d i n g
No funding was received for this study.

Table 3 :
Treatment Clinical Aspects, Immunophenotypic Analysis and Survival Rate of Chronic Lymphocytic Leukaemia Patients in Erbil City, Iraq included in the final analysis.Of these, 67 (63.8%) were male and 38 (36.2%) were female.The mean age at presentation was 63.3 ± 10.7 years.Most patients (70.5%) were ≥60 years, with only 9.5% <50 years.The age at diagnosis ranged from 28-81 years old, with a median of 65 years.The main clinical presentations were splenomegaly (64.8%) pallor (61.9%) and lymphadenopathy (60%).Hepatomegaly was observed in 21.9% of patients.Modified Rai staging showed a high risk (stage III or IV) of CLL in 59.1%, an intermediate risk (stage I or II) in 27.6% and a low risk (stage 0) in 13.3% of patients.In terms of Binet staging, 55.2% of patients were stage C, 17.1% were stage B and 27.6% were stage A [Table 1].Most patients (72.4%) were from Erbil and other cities in the Kurdistan region of Iraq, while the rest were from other northern and western Iraqi cities.

Table 4 :
Correlation between survival rate and selected characteristics among chronic lymphocytic leukaemia patients in Erbil, Iraq (N = 105) Hb = haemoglobin; WBC = white blood cells; LDH = lactate dehydrogenase.