In the 1970s, patients with sickle cell disease (SCD) were not expected to live into adulthood, but today, patients may live into their 40s and 50s. In a report published in Blood, Samir K. Ballas, MD, from the Department of Medicine at Jefferson Medical College at Thomas Jefferson University, and authors described outcomes for an even rarer population – patients with SCD who have survived into their 80s – to determine if there are any demographic or clinical features related to their longevity.
"Major strides in the management of SCD have been achieved during the last 45 to 50 years," Dr. Ballas told ASH Clinical News. "With the advent of stem cell transplantation and gene therapy, cure of SCD is probable."
Dr. Ballas and colleagues identified four female patients with SCD – three U.S. citizens enrolled at the Sickle Cell Center of Thomas Jefferson University, and one from Brazil – who were between 82 and 86 years of age. Two patients were African American, one was Italian American, and the other was African Brazilian.
"All described patients are women," the authors wrote. "The reason why adult females with SCD live longer than males is not known. One possibility is relatively lower blood viscosity due to lower hemoglobin (Hb) and hematocrit levels in women."
The patients also had "excellent" family support and adherence to medication intake, appointments, and referrals. See TABLE 1 for other demographic information related to longevity.
"Providers who take care of patients with SCD should determine certain risk factors that are often associated with the outcome of their disease," Dr. Ballas said. "Women who never had a stroke, never had recurrent acute chest syndrome (ACS), had infrequent painful crises, and have high fetal hemoglobin usually – but not always – have relatively mild disease, longer survival, and better quality of life." Other features related to good prognosis included infrequent vaso-occlusive crises that required hospitalization, low white blood cell counts, low Hb level, and normal biochemical parameters. See TABLE 2 for an overview of the patients' laboratory data.
None of the patients were being treated with hydroxyurea – the only approved therapy for SCD treatment – because none of them met the inclusion criterion of having at least three veno-occlusive crises that required hospitalization in the immediate previous year.
Despite the longevity of these patients, they still experienced disease-related complications and comorbidities that typically emerge in older patients, such as ACS.
The patients described in this study had different ancestries, cultures, and countries, but similar "desirable" features of SCD, the authors noted. "Their lifestyle of no smoking, no or occasional alcohol, normal body mass index, compliance, and excellent family support were, most likely, important contributors to their longevity. … These four women may provide a blueprint of how to live a long life despite having a serious medical condition like SCD," they concluded.
The study is limited by its small sample size, and entirely descriptive nature. "Only two patients had sickle cell anemia, which is the most severe type of SCD," Dr. Ballas added. "Another limitation is that we do not really know why all the patients described were women. The environmental factors should be applicable to men as well."
Reference
Ballas SK, Pulte ED, Lobo C, Riddick-Burden G. Case series of octogenarians with sickle cell disease. Blood. 2016 October 4. [Epub ahead of print]
TABLE 1. Demographic and Clinical Data | ||||
Patient A | Patient B | Patient C | Patient D | |
VOC/year | 1-2 | 0-1 | 0-3 | 0-1 |
Smoking | No | No | No | No |
Alcohol | No | Occasional | No | Occasional |
BMI | 21.6 | 20.4 | 24.8 | 23.1 |
Comorbidities | · Complete heart block· Glaucoma
· OU · Mild Parkinson's disease |
· Paroxysmal AFIB· IBS
· MVP · Osteoporosis |
· Osteoma of mandible· Depression | · Type 2 diabetes |
Status | Alive | Deceased | Deceased | Deceased |
Cause of death | N/A | Cardiac complications | Unknown | ACS plus septicemia |
VOC = veno-occlusive crises; BMI = body mass index; OU = oculus uterque; AFIB = atrial fibrillation; IBS = irritable bowel syndrome; MVP = mitral valve prolapse; N/A = not applicable; ACS = acute chest syndrome |
TABLE 2. Laboratory Data Collected | ||||
Test | Patient A | Patient B | Patient C | Patient D |
Hemoglobin | 8.1 g/dL | 8.6 g/dL | 9.4 g/dL | 7.8 g/dL |
Hematocrit | 24.4% | 26.4% | 27.3% | 23.2% |
MCV | 90 fL | 93 fL | 81 fL | 82 fL |
Reticulocytes | 11.2% | 9.1% | 5.8% | 2.4% |
WBC | 8.6×109/L | 7.8×109/L | 6.8×109/L | 6.5×109/L |
Platelets | 243×109/L | 238×109/L | 229×109/L | 125×109/L |
Hb F | 12% | 8.8% | 1.8% | 2% |
Ferritin | 2,660 ng/mL | 464 ng/mL | 101 ng/mL | 1,250 ng/mL |
α-genes | 3 | 3 | 4 | ND |
ß-haploytpe | BEN/BEN | BEN/BEN | BEN/CTYPE 1 | ND |
MCV = mean corpuscular volume; WBC = white blood cell count; Hb F = fetal hemoglobin; ALT = alanine aminotransaminase; AST = aspartate aminotransferase; ND = not done; LDH = lactate dehydrogenase; ALK = alkaline phosphatase; UA = uric acid; BEN = benin |