Clinical and genetic factors are associated with pain and hospitalisation rates in sickle cell anaemia in Cameroon

Br J Haematol. 2018 Jan;180(1):134-146. doi: 10.1111/bjh.15011. Epub 2017 Dec 3.

Abstract

We aimed to investigate the clinical and genetic predictors of painful vaso-occlusive crises (VOC) in sickle cell disease (SCD) in Cameroon. Socio-demographics, clinical variables/events and haematological indices were acquired. Genotyping was performed for 40 variants in 17 pain-related genes, three fetal haemoglobin (HbF)-promoting loci, two kidney dysfunctions-related genes, and HBA1/HBA2 genes. Statistical models using regression frameworks were performed in R® . A total of 436 hydoxycarbamide- and opioid-naïve patients were studied; median age was 16 years. Female sex, body mass index, Hb/HbF, blood transfusions, leucocytosis and consultation or hospitalisation rates significantly correlated with VOC. Three pain-related genes variants correlated with VOC (CACNA2D3-rs6777055, P = 0·025; DRD2-rs4274224, P = 0·037; KCNS1-rs734784, P = 0·01). Five pain-related genes variants correlated with hospitalisation/consultation rates. (COMT-rs6269, P = 0·027; FAAH-rs4141964, P = 0·003; OPRM1-rs1799971, P = 0·031; ADRB2-rs1042713; P < 0·001; UGT2B7-rs7438135, P = 0·037). The 3·7 kb HBA1/HBA2 deletion correlated with increased VOC (P = 0·002). HbF-promoting loci variants correlated with decreased hospitalisation (BCL11A-rs4671393, P = 0·026; HBS1L-MYB-rs28384513, P = 0·01). APOL1 G1/G2 correlated with increased hospitalisation (P = 0·048). This first study from Africa has provided evidence supporting possible development of genetic risk model for pain in SCD.

Keywords: Africa; Cameroon; acute vaso-occlusive painful crises; genetics; sickle cell disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Alleles
  • Anemia, Sickle Cell / blood
  • Anemia, Sickle Cell / complications*
  • Anemia, Sickle Cell / epidemiology*
  • Anemia, Sickle Cell / genetics
  • Cameroon / epidemiology
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Erythrocyte Indices
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease*
  • Genetic Variation
  • Haplotypes
  • Hemoglobins, Abnormal / genetics
  • Hospitalization* / statistics & numerical data
  • Humans
  • Kidney Function Tests
  • Male
  • Middle Aged
  • Mutation
  • Pain / epidemiology*
  • Pain / etiology*
  • Patient Acceptance of Health Care
  • Polymorphism, Single Nucleotide
  • Prospective Studies
  • Quantitative Trait Loci
  • Young Adult

Substances

  • Hemoglobins, Abnormal