Diagnosis patterns of sickle cell disease in Ghana: a secondary analysis.

BACKGROUND: Despite having the highest prevalence of sickle cell disease (SCD) in the world, no country in Sub-Saharan Africa has a universal screening program for the disease. We sought to capture the diagnosis patterns of SCD (age at SCD diagnosis, method of SCD diagnosis, and age of first pain crisis) in Accra, Ghana. METHODS: We administered an in-person, voluntary survey to parents of offspring with SCD between 2009 and 2013 in Accra as a part of a larger study and conducted a secondary data analysis to determine diagnosis patterns. This was conducted at a single site: a large academic medical center in the region. Univariate analyses were performed on diagnosis patterns; bivariate analyses were conducted to determine whether patterns differed by participant's age (children: those < 18 years old whose parents completed a survey about them, compared to adults: those > = 18 years old whose parents completed a survey about them), or their disease severity based on SCD genotype. Pearson's chi-squared were calculated. RESULTS: Data was collected on 354 unique participants from parents. Few were diagnosed via SCD testing in the newborn period. Only 44% were diagnosed with SCD by age four; 46% had experienced a pain crisis by the same age. Most (66%) were diagnosed during pain crisis, either in acute (49%) or primary care (17%) settings. Children were diagnosed with SCD at an earlier age (74% by four years old); among the adults, parents reflected that 30% were diagnosed by four years old (p < 0.001). Half with severe forms of SCD were diagnosed by age four, compared to 31% with mild forms of the disease (p = 0.009). CONCLUSIONS: The lack of a robust newborn screening program for SCD in Accra, Ghana, leaves children at risk for disease complications and death. People in our sample were diagnosed with SCD in the acute care setting, and in their toddler or school-age years or thereafter, meaning they are likely being excluded from important preventive care. Understanding current SCD diagnosis patterns in the region can inform efforts to improve the timeliness of SCD diagnosis, and improve the mortality and morbidity caused by the disease in this high prevalence population.

Forced TR2/TR4 expression in sickle cell disease mice confers enhanced fetal hemoglobin synthesis and alleviated disease phenotypes.

Sickle cell disease (SCD) is a hematologic disorder caused by a missense mutation in the adult ß-globin gene. Higher fetal hemoglobin (HbF) levels in red blood cells of SCD patients have been shown to improve morbidity and mortality. We previously found that nuclear receptors TR2 and TR4 repress expression of the human embryonic ε-globin and fetal γ-globin genes in definitive erythroid cells. Because forced expression of TR2/TR4 in murine adult erythroid cells paradoxically enhanced fetal γ-globin gene expression in transgenic mice, we wished to determine if forced TR2/TR4 expression in a SCD model mouse would result in elevated HbF synthesis and thereby alleviate the disease phenotype. In a "humanized" sickle cell model mouse, forced TR2/TR4 expression increased HbF abundance from 7.6% of total hemoglobin to 18.6%, accompanied by increased hematocrit from 23% to 34% and reticulocyte reduction from 61% to 18%, indicating a significant reduction in hemolysis. Moreover, forced TR2/TR4 expression reduced hepatosplenomegaly and liver parenchymal necrosis and inflammation in SCD mice, indicating alleviation of usual pathophysiological characteristics. This article shows that genetic manipulation of nonglobin proteins, or transcription factors regulating globin gene expression, can ameliorate the disease phenotype in a SCD model animal. This proof-of-concept study demonstrates that modulating TR2/TR4 activity in SCD patients may be a promising therapeutic approach to induce persistent HbF accumulation and for treatment of the disease.