PREDICTORS OF CLINICAL AND FETAL HEMOGLOBIN RESPONSES TO HYDROXYUREA IN SICKLE CELL ANEMIA CHILDREN IN JOS, NIGERIA.

Principal Investigator: Dr Ofakunrin, Akinyemi Olugbenga David

Department of Paediatrics, Jos University Teaching Hospital, Jos

E mail: aodofak@yahoo.com

Phone number: 08038345783

Purpose of research: To investigate the predictors of clinical and fetal hemoglobin responses to hydroxyurea therapy in sickle cell anemia children in Jos, Nigeria.

Date of commencement: Jan 2016

Mentors: Associate Prof. E.S Okpe (FWACP), Prof. Stephen Oguche (FMCPaed)

Department of Paediatrics

University of Jos, Jos

1. ABSTRACT

Background

Sickle cell anemia (SCA) is a chronic, non communicable disease with significant morbidity and mortality in children.¹ Bone marrow transplant is a known cure for SCA but the procedure is hampered by many factors including not being widely available, high cost, difficulty in getting a suitable donor and other associated life threatening complications.^{2, 3, 4}

Hydroxyurea (HU) has emerged as the major breakthrough in the therapy of sickle cell disease. It is the only currently available agent approved by the U.S, Food and Drug Administration that is capable of modifying the disease pathogenesis and its use has transformed the treatment of sickle cell disease worldwide.^{5, 6, 7}Clinical efficacy of HU in the reduction of sickle cell crisis, chronic organ damage and overall mortality has also been reported.^{8, 9, 10} Its safety in children as young as 6 to 9 months has been documented.^{11, 12}

In spite of its demonstrated efficacy and safety,^{11, 12, 15} not all patients however showed desired clinical and laboratory (fetal hemoglobin) responses to the medication.^{13, 14} Therefore, this study aims to determine the predictors of clinical and fetal hemoglobin response to HU among paedatric sickle cell anaemia patients in Jos University Teaching Hospital (JUTH) Plateau State, Nigeria.

Subjects and methods.

This will be an interventional study involving 54 paediatric sickle cell anaemia patients which will be recruited from the haematology clinic of JUTH. The entry criteria will include SCA (HbSS) patients at steady state for  2 weeks or more prior to the time of enrolment, with moderate to severe disease according to the SCA severity scoring system¹⁶ (see appendix) etc. Baseline clinical history of the subjects will be obtained from case records and use of recall. Patients’ characteristics such as age, sex, ethnicity etc will be documented and physical examination done while baseline percentage HbF will be measured.

Hydroxyurea will be administered to them using standard treatment protocol and precaution.¹⁵ Subjects will be monitored monthly or as need arises for painful crises, need for hospitalization etc; and HbF and Full Blood Count (FBC) will be measured at specified intervals. 

History and physical examination will also be obtained at each visit. Compliance with hydroxyurea will be reinforced through counseling while noncompliance will be assessed by counting any returned pills at each visit.

 

Ethical consideration

Ethical clearance will be obtained from the research and ethics committee of JUTH and consent/ assent from the parent and the subjects.

 

Statistical analysis

Data will be processed and analyzed using Epi- info statistical software version 3.5.3. Qualitative and quantitative data will be presented using frequency table and mean respectively. Paired student's t test will be used to determine the difference in mean values at baseline and after introduction of HU. Chi square test will be used to test for association between clinical/fetal hemoglobin response and patients’ characteristics. Multivariate analysis will be used to determine factors that predict clinical and fetal hemoglobin response. A 95% confidence interval and p - value of < 0.05 will be considered statistically significant.

 

2. NIH-FORM BIOSKETCH

BIOGRAPHICAL SKETCH
NAME OFAKUNRIN, AKINYEMI OLUGBENGA DAVID	POSITION TITLE Lecture I, College of Medicine, University of Jos. Consultant Paediatrician, Jos University Teaching Hospital, Jos Nigeria         UNU
COMMON USER NAME GBENGA
EDUCATION/TRAINING
INSTITUTION AND LOCATION	DEGREE (if applicable)	MM/YY	FIELD OF STUDY
University of Ilorin, Nigeria	MBBS	03/2004	Medicine and Surgery
National Postgraduate Medical college of Nigeria	FMCPaed	05/2015	Paediatrics

 

1. Personal Statement

The goal of the proposed research is to investigate the predictors of clinical and fetal hemoglobin responses to hydroxyurea.  Specifically, we plan to determine factors such as age, sex, ethnicity, socioeconomic status, nutritional status, baseline % fetal hemoglobin etc that could predict favorable clinical and fetal hemoglobin responses to hydroxyurea therapy in sickle cell anemia patients in Nigeria.

I am a junior faculty with a growing interest in research and passion to develop myself to a level where I could conduct various researches of international standard that will impact positively on the health of sickle cell anemia patients in Nigeria and the world at large. I really appreciate the opportunity provided by this body to help the junior faculties develop their potentials. This gesture could also afford me the opportunity to collaborate with international researchers in the future, which could translate into the possibility of developing a “safer” cure for sickle cell anemia patients.

I have worked as one of the main research doctors in an international multicenter study tagged ‘’ Preventing kernicterus in Nigeria”, saving lives at birth project.  I also recently conducted the research for my dissertation as part fulfillment of the award of the Fellowship of the National Postgraduate Medical college of Nigeria in the faculty of Paediatrics, where I studied the relationship between birth weight and serum zinc in mothers and their babies. The above studies gave me an insight, experience and motivation necessary to successfully carry out this proposed work. My mentors are also renowned researchers who can guide me appropriately.

 In summary, I have stated my passion for research and willingness to carry out productive research in an area of high relevance for our sickle cell anemia patients, and my modest experiences have prepared me to lead the proposed project. 

2. Positions and Honors

Positions and Employment

2004-2005      House Officer, University of Ilorin Teaching Hospital, Ilorin, Nigeria

2005-2006       Medical Officer, Department of Family Medicine, Jos University Teaching                                     Hospital, Jos, Nigeria

2006-2008       Registrar, Department of Paediatrics, Jos University Teaching 

                        Hospital, Jos, Nigeria

2008-2012       Senior Registrar, Department of Paediatrics, Jos University Teaching 

                        Hospital, Jos, Nigeria

2015-date        Lecturer I, Department of Paediatrics, University of Jos, Jos, Nigeria /

                        Consultant Paediatrician, Jos University Teaching Hospital, Jos, Nigeria

Other Experience and Professional Memberships

2004-               Member, Nigerian Medical Association

2009- 2011      Treasurer, Association of resident doctors, JUTH.

2009-date        Volunteer, Heart Aid Trust, Jos

Honors

2004           Distinction in Pathology, College of Medicine, University   of   Ilorin .

 

2004           Best Graduating Student in Pathology, College of Medicine, University of Ilorin.

 

2004           Best Graduating Student in Hematology, College of Medicine, University of Ilorin.

 

2006          State Merit award, National Youth Service Corps, Plateau State

 

2006         Merit award for outstanding performance in 2006 by Jos University Teaching Hospital                   Management Board.

 

2009          Best Resident award in JUTH by the 2009 set of Medical Student of University of Jos

3. Peer-reviewed Publications

1. Oguche S, Ofakunrin AOD, Toma BO. Meningitis Outbreak in Jos: A report of 29 cases seen in Paediatric Department of Jos University Teaching Hospital, Jos, Nigeria (2012).  Journal of Medicine in the Tropics. 2012;14:2

 

2.  Idowu A,  Deji S A, Aremu O A, Bojuwoye O.M, Ofakunrin A.D.(2015) Birth preparedness and complication readiness among women attending antenatal clinics in Ogbomoso, South west, Nigeria. International Journal of MCH and AIDS 2015; 4(1): 1-10  

4. Research Support

Ongoing Research Support

Prevention of kernicterus in Nigeria, saving lives at birth project. Prof S. Oguche  (PI) 2014 till date

The goal of this study is to reduce the incidence and mortality from acute bilirubin encephalopathy in Nigeria.

Role: Research Clinician

 

3. BUDGET

BUDGET CATEGORY	UNIT COST	MULTIPLYING FACTOR	TOTAL COST
Medication:
Hydroxyurea cap	#30 per 500mg capsule	30 x 365 days x 54patients	591,300
Laboratory investigations:
Full blood count	#500 per test	500 x 9 tests x 54	243,000
HBF assay	#2500 per test	2500 x 3 tests x 54	405,000
Consumables:
Gloves	# 500 per packet	500 x 6 packets	3,000
Syringes	#400 per packet	400 x 4 packets	1,600
Cotton wool	#500 per pack	500 x 5 packs	2,500
Methylated spirit	#2500 per 5L	2500 x 1	2,500
Sample bottles	#30 per bottle	30 x 1000 bottles	30, 000
Personnel:
Research assistant	12,000	12,000 X 12months	144,000
TOTAL			1,422,900

 

4. BUDGET JUSTIFICATION

Medication:

Hydroxyurea is the drug being studied and it is going to be administered daily to each patient for 365 days

Laboratory investigation

FBC will be done every 2 weeks x 3, every 4 weeks x 2 and subsequently every 8 weeks till the end of the study making a total of 9 times. This is to monitor patients for toxicity and response to medication.

HBF assay will be done at baseline and there after every 6 months. (Quarterly measurement would have been desirable but for the cost).

Personnel:

Mentor: Associate Prof. E.S Okpe and Prof S. Oguche will provide adequate supervision and scientific support all through the duration of the research. No salary requested.

 

Principal Investigator: Dr Ofakunrin A.O.D will be responsible for protocol design, recruitment, data collection, analysis and interpretation of results. No salary requested

 

Research Assistant: Will coordinate logistics, data collection and laboratory investigations.

 

Consumables:  

These will be needed in the process of sample collection.

 

5. Project Narrative

 This research will provide information on factors that could predict positive clinical and laboratory (HbF) responses to hydroxyurea therapy. This could help to identify a cohort of patients that could benefit maximally from hydroxyurea. It could also lay a foundation for future genetic testing to unravel reason for variation seen, if there is any.

 

6. Research Plan

This study aims to determine the predictors of clinical and fetal hemoglobin responses of SCA patients to hydroxyurea.

1. Specific Aims

1. To determine the clinical response of SCA patients to hydroxyurea such as occurrence of vaso-occlusive crisis, need for blood transfusion, hospitalization etc
2. To determine fetal hemoglobin response to hydroxyurea
3. To determine the relationship between clinical response and patients’ characteristics such as age, sex, ethnicity, time of diagnosis, socioeconomic status, nutritional status, fetal hemoglobin level etc
4. To determine the relationship between fetal hemoglobin response and patients’ characteristics such as age, sex, ethnicity, time of diagnosis, socioeconomic status, nutritional status etc

 

2. Background and Significance

Sickle cell anemia (SCA) is a chronic, non communicable disease with significant morbidity and mortality in children globally.¹An unpublished data from the records of the department of paediatrics Jos University Teaching Hospital (JUTH),  reveals that SCA constitute about 17% of total paediatric admissions and 9% of the total mortality among paediatric patients. Bone marrow transplant is a known cure for SCA but the procedure is hampered by many factors including not being widely available, high cost, difficulty in getting a suitable donor and other associated life threatening complications.^{2, 3,   4}

Hydroxyurea (HU) has emerged as the major breakthrough in the therapy of sickle cell disease. It is the only currently available agent approved by the U.S, Food and Drug Administration that is capable of modifying the disease pathogenesis and its use has transformed the treatment of sickle cell disease worldwide.^{5, 6, 7}Clinical efficacy of HU in the reduction of sickle cell crisis, chronic organ damage and overall mortality has also been reported.^{8, 9, 10} Its safety in children as young as 6 to 9 months of age has also been shown by recent studies.^{11, 12}

In spite of its demonstrated efficacy and safety, ^{11, 12, 15} not all patients however showed desired clinical and laboratory (fetal hemoglobin) responses to the medication.^{13, 14} Therefore, this study aims to determine the predictors of clinical and fetal hemoglobin response to HU among sickle cell anaemia paediatric  patients in Jos University Teaching Hospital, Plateau State, Nigeria.

Hydroxyurea has been used in the management of four SCA patients in the department of Paediatrics, JUTH up till date with favourable positive outcomes; and the experience upon which this study will leverage on for a large scale hydroxyurea use in SCA management.

3. Experimental Design and Methods

Study Population

This will comprise of all paediatric sickle cell anaemia patients attending the paediatric haematology out-patient clinic of the Jos University Teaching Hospital.

 Study design

This will be an interventional study with a before and after design which will be conducted in two phases namely pre-intervention and intervention.

 Sampling Technique

All paediatric SCA patients attending paediatric haematology out-patient clinic of JUTH who have met the inclusion criteria and whose parents or care givers consent to the study will be recruited consecutively on every clinic day until the sample size is met. This is estimated to take a period of 4 to 6 weeks. Based on the departmental records, there are about 550 SCA children being presently catered for at the clinic with an average weekly attendance of 30 to 35 patients.

Inclusion Criteria

SCA (Hb SS) paediatric patients who are in steady state for 2 weeks or more prior to the time of enrolment for the study, who have moderate to severe disease according to SCA severity scoring system in Nigeria (see appendix), ¹⁶ not previously on hydroxyurea or any other drugs that could induce HbF production, who have not been transfused in the last 3 months before the commencement of the study and whose parent or caregiver has consented to participate in the study will be included.

Exclusion Criteria

Sickle cell anemia patients with HIV infection, malignancy or other chronic conditions that could potentiate HU toxicity.

Sample Size Determination

The sample size for this study will be determined using the formula.¹⁷

n =   (Zα+Z_β) ² P (1-P)      

                    d²

where

n      - Minimum sample size

 z_α      - Standard normal deviate at 95% confidence interval = 1.96

 z_β     - Statistical power of the test set at 80% = 0.84

P =  P_{1 +} P₂

            2

 Where P₁ is mean percentage HbF at baseline from a previous study which was 7.3%.¹⁵

              P₂ is the expected mean percentage HbF at the end this study which is 21.3%.

d   is the expected difference in percentage  HbF at the end of this study which is P₂ – P₁ = 14%

n = (1.96 + 0.84)² x 0.143 (1 – 0.143)

                                (0.14)²                  

  n = 49 

An attrition rate of 10% will be added making a minimum sample size of 54 for this study.

 

Study Phases

Baseline

Baseline clinical history of the patients will be obtained by checking case records and use of recall to determine number of previous vaso- occlusive crises, transfusions, hospitalizations etc. Patients’ characteristics such as age, sex, ethnicity, socioeconomic status etc will also be documented. Physical examination will be carried out while baseline FBC will be measured using standard method and % HbF using High Performance Liquid Chromatography method. The disease severity score (see appendix) of the patient will be determined from the patient’s history, physical examination and the full blood count. Information regarding the study especially the risk and benefits of hydroxyurea will be provided to the patients/parents/care givers. Primary and secondary phone contacts as well as the residential address of the parents/care givers will be obtained and compiled. The phone contact will be used to send reminder bulk text messages as well as voice calls for scheduled appointment visits while residential contact will be used for tracking of defaulting subjects.

 

Intervention phase

Hydroxyurea will be administered to the subjects using standard treatment protocol and precaution.¹⁵ Patients will be monitored monthly or as need arises for painful crises, need for hospitalization, need for transfusion etc. Full Blood Count (FBC) and HbF will also be measured at specified intervals (FBC will be done every 2 weeks x 3, every 4 weeks x 2 and subsequently every 8 weeks till the end of the study making a total of 9 times). This is to monitor patients for toxicity and response to medication. HBF assay will be done at baseline and there after every 6 months.

Furthermore, patients’clinical history and physical examination including anthropometry will also be obtained monthly. Compliance with HU therapy will be reinforced through counseling. Noncompliance with therapy will be assessed by counting any returned pills at each visit. The disease severity score of the patients will also be determined at the end of the study.

Ethical consideration

Ethical clearance will be obtained from the research and ethics committee of the Jos University Teaching Hospital before the study is commenced. Consent /assent will be obtained from the parent and the patients.

Statistical analysis

Data will be processed and analyzed using Epi info statistical software version 3.5.3. Clinical response, one of the outcome variables will be assessed using SCA severity scoring system¹⁶ which has component characteristics such as frequency of painful crises, number of hospitalization and blood transfusion etc.

The socioeconomic status of the family will be determined using the Olusanya et al¹⁸ index scoring method while the nutritional status will be determined from the anthropometric measurements which include the weight, height etc.

Qualitative data such as sex, socioeconomic status etc will be presented using frequency table. Mean and standard deviation will be used to present quantitative data such as age, weight, height, SCA severity score etc. Paired student's t test will be used to determine the difference in mean values at baseline and after introduction of hydroxyurea. Chi square test will be used to test for association between clinical response and characteristics of the patients such as socioeconomic status, nutritional status etc as well as grading of fetal hemoglobin response and characteristics of the patients. Multivariate analysis will be used to determine factors that predict clinical and fetal hemoglobin response. A 95% confidence interval will be used and p - value of < 0.05 will be considered statistically significant.

 

7. References

1. Rees, DC, Williams, TN, and Gladwin, MT. Sickle-cell disease. Lancet. 2010; 376: 2018–2031
2. National Heart, Lung, and Blood Institute, National Institutes of Health (2002). The Management of Sickle Cell Disease (NIH Publication No. 02-2117). Available online: http://www.nhlbi.nih.gov/health/prof/blood/sickle/.
3. Steinberg MH (2012). Sickle cell disease and other hemoglobinopathies. In L Goldman, A Shafer, eds., Goldman's Cecil Medicine, 24th ed., pp. 1066-1075. Philadelphia: Saunders.
4. Wang WC (2009). Sickle cell anemia and other sickling syndromes. In JP Greer et al., eds., Wintrobe's Clinical Hematology, 12th ed., pp. 1038-1082. Philadelphia: Lippincott Williams and Wilkins.
5. Charache S, Terrin ML, Moore RD. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med 1995; 332:1317-22.
6.  Schechter A, Rodgers G. Sickle cell anemia: basic research reaches the clinic. New Engl J Med 1995; 332:1372-4.
7.  Halsey C, Roberts I. The role of hydroxyurea in sickle cell disease. Br Haematol 2003;120:177-86
8. Manwani D, Frenette PS. Vaso-occlusion in sickle cell disease: Pathophysiology and novel targeted therapies. Blood. 122(24): 3892-8, 2013
9.  Platt OS, Brambilla DJ, Rosse WF, et al. Mortality in sickle cell disease - Life expectancy and risk factors for early death. N Engl J Med. 1994; 330(23):1639–1644.
10. Lobo CL, Pinto JF, Nascimento EM, Moura PG, Cardoso GP, Hankins JS. The effect of hydroxcarbamide therapy on survival of children with sickle cell disease. Br J Haematol 2013; 161(6):852-860.
11. Thornburg CD, Files BA,Luo Z, Miller ST, Kalpatthi R, Iyer R, Seaman P, Lebensburger J, Alvarez O, Thompson B, Ware RE, Wang WC, BABY HUG Investigators. Impact of hydroxyurea on clinical events in the BABY HUG trial. Blood 120: 4304–4310, 2012
12. Wang WC, Wynn LW, Rogers ZR, Scott JP, Lane PA, Ware RE.  A two-year pilot trial of hydroxyurea in very young children with sickle-cell anemia. J Pediatr 2001;139(6):790-796.
13. Zimmerman SA, Schultz WH, Davis JS. Sustained long-term hematologic efficacy of hydroxyurea at maximum tolerated dose in children with sickle cell disease. Blood 2004; 103(6):2039-2045.
14.  Heeney MM, Ware RE. Hydroxyurea for children with sickle cell disease. Pediatr Clin North Am 2008; 55(2):483-501.
15. Kinney TR, Helms RW, O'Branski EE, et al Safety of hydroxyurea in children with sickle cell anemia: results of the HUG-KIDS study, a phase I/II trial. Blood. 1999;94:1550-1554
16. Adegoke SA, Kuti BP. Evaluation of clinical severity of sickle cell anaemia in Nigerian children. Journal of Applied Haematology. 2013; 4(2): 58-64.
17. Jekel JF, Katz DL, Elmore JG. Sample size randomization and probability theory. In: Epidemiology, biostatistics and preventive medicine. Philadelphia: WB Saunders; 2^nd edition 2001. p.199.
18. Olusanya O, Okpere E, Ezimokhai M. The importance of social class involuntary fertility control in a developing country. W Afr J Med. 1985; 4:205-206.
19. Plan for Protection of Human Subjects.

Risks/benefits to participants

This research will be done at minimal risk to the patients and all procedures will be painstakingly explained to the parents/ patients in a language they understand. The benefits to the subjects will be the availability of drugs and potential improvement in the clinical condition occasioned by the drug. All investigations will be at no cost to the subjects. The possible side effects will also be explained to them and they will be adequately managed if any such occurs.

Method of collecting informed consent

Subjects would be counseled repeatedly during the entire study period. The risks and the benefits of the study will be explained to them in a language they can understand.  They would also be educated about their rights to be treated with respect, including respect for their decision whether or not they want to be part of the study. Specifically they will be told that their choice of not being in the study will not result in any penalty or loss of any benefit for which they are entitled including their right to seek routine medical care at the centre.

Plans to safeguard the patient’s information

Confidentiality of the subjects’ personal information will be assured. However, they would be informed that participating in the study implies that they have given consent for their personal information and medical histories to be included in the study results and that these may be used for teaching, publications or presentation at scientific meetings. They will also be made to understand that their identities will not be disclosed during such use.

1. Project Mentor:

Associate Professor E.S Okpe a Consultant Paediatrician (Haematology/Oncology)

8.         IRB Approval

Ethical approval will be obtained from the JUTH Ethics and Research Committee.

     g.         Appendix

 SCA Disease Severity Scoring System in Nigeria

This was introduced by Adegoke and Kuti¹⁶ as a simple and reproducible tool for scoring the severity of SCA in Nigerian children. The scoring system employed clinico-laboratory parameters and related these to socio-demographic factors that may influence the clinical course of the disease. Based on the parameters, subjects were divided into those with mild (total score <8), moderate (8-17) and severe disease (>17) groups. The scoring system took into consideration the present state of the children, their past medical history in the previous 12months and the life time cumulative incidence of complications of SCA.

 SCA Disease Severity Scoring System¹⁶

 

PARAMETERS	SCORE
1. Number of painful episodes( warranting parenteral analgesia) in the previous 12 months: a. 0 b. 1 c. 2 or 3 d. > 3	0 1 2 3
2. Number of blood transfusions in the previous 12months: a.  0 b. 1 c. 2 or 3 d. > 3	0 1 2 3
3. Number of hospitalizations in the previous 12 months: a. 0 b. 1 c. 2 or 3 d. > 3	0 1 2 3
4. Liver enlargement: a. < 2 cm b. 2 to 5 cm c. > 5 cm	0 1 2
5. Splenic enlargement: a. < 5 cm b. 5 to 10 cm c. > 10 cm	0 1 2
6. Packed cell volume: a.  ≥ 0.24 b. 0.18–0.23 c.  < 0.18	0 1 2
7. White blood cell count: a.  < 11x109/L b. 11-15x109/L c. >15x109/L	0 1 2
8.  For lifetime cumulative incidence of specific complications, score: CVD is/was present CVD absent ACS is/was present       ACS absent c. pneumococcal meningitis is/was present,     pneumococcal meningitis absent d. AVN is present     AVN absent e. Gall stone, chronic leg ulcer, osteomyelitis, or priapism is/was present    when absent	5 0 3 0 3 0 2 0 1   0