Sickle cell disease cuts HIV risk in U.S. Blacks: 400,000-person review
By Mark Mascolini
Sickle cell disease lowers the odds of HIV infection about 70 percent, according to analysis of 423,431 records of adult African-Americans admitted to the hospital from 1997 through 2009. In contrast, sickle cell disease raised chances of infection with hepatitis B or C virus (HBV or HCV).
Sickle cell disease, often called sickle-cell anemia, is an inheritable disorder in which oxygen-carrying red blood cells assume a sickle shape instead of the normal disk shape. Sickle cell disease is more common in people of African and Mediterranean descent. It causes painful “crises” that affect back bones, long bones, and the chest.
Research suggests that HIV infection progresses more slowly in people with sickle cell disease. To get a better understanding of the relation between sickle cell disease and HIV infection, researchers analyzed National Hospital Discharge Survey data on adult African Americans, using multiple regression analysis to test for an association between sickle cell disease and HIV.
The analysis involved 423,431 hospital records divided into two periods: 1997-2003 (53 percent of records) and 2004-2009 (47 percent of re-cords). An HIV diagnosis was less common among people with than without sickle cell disease—1.5 percent versus 3.3 percent.
Logistic regression determined that HIV infection lowered the odds of sickle cell disease 76 percent in 1997-2003 (odds ratio [OR] 0.24, 95 percent confidence interval [CI] 0.18 to 0.32) and 69 percent in 2004-2009 (OR 0.31, 95 percent CI 0.22 to 0.42).
In contrast, having sickle cell disease doubled the odds of HCV infection (OR 2.01, 95 percent CI 1.56 to 2.59, in 1997-2003 and OR 2.12, 95 percent CI 1.71 to 2.63, in 2004-2009). Sickle cell disease also inflated the odds of HBV infection, though significantly only in the second period (OR 1.15, 95 percent CI 0.72 to 1.83, in 1997-2003 and OR 1.82, 95 percent CI 1.24 to 2.68, in 2004-2004).
The authors propose that “the lower risk of HIV comorbidity, but not HCV and HBV, with sickle cell disease is consistent with the possibility that sickle cell disease has a unique effect in altering the risk of HIV infection or progression.”
“Investigation of how the haemolytic and immunological changes of sickle cells disease influence HIV,” the researchers suggest, “might lead to new therapeutic or preventive approaches.”
Source: Mehdi Nouraie, Sergei Nekhai, Victor R Gordeuk. Sickle cell disease is associated with decreased HIV but higher HBV and HCV comorbidities in US hospital discharge records: a cross-sectional study. Sexually Transmitted Infections. 2012; 88: 528-533.