Iron, haptoglobin phenotype, and HIV-1 viral load: a cross-sectional study among pregnant Zimbabwean women.
BACKGROUND
Viral load is a determinant of HIV-1 progression and transmission. Iron status and the phenotype of haptoglobin, a heme-binding acute phase reactant, may be determinants of viral load. We aimed to describe the effect of iron status, haptoglobin phenotype (Hp), and other predictors on HIV-1 viral load.


METHODS
Based on a cross-sectional study among 1669 antenatal care attenders (22-35 weeks) in Zimbabwe, 526 (31.5%) were found to be HIV infected. The role of season, age, gravidity, gestational age, malaria parasitemia, Hp, and elevated serum alpha(1)-antichymotrypsin (ACT) as well as serum ferritin, folate, retinol, and beta-carotene on HIV viral load among the 526 HIV-infected women was assessed using multiple linear regression analysis.


RESULTS
The distribution of Hp 1-1 (32%), Hp 2-1 (48%), and Hp 2-2 (20%) was not different from that of 53 uninfected women. Mean viral load was 3.85 log(10) (95% CI: 3.77-3.93) genome equivalents (geq)/mL, ranging from 3.77 (95% CI: 3.64-3.90) geq/mL in women with Hp 1-1 to 4.05 (95% CI: 3.81-4.21) geq/mL in women with Hp 2-2. With elevated serum ACT controlled for, women with Hp 2-2 had viral loads twice (95% CI: 1.4-4.0, p =.002) that of women with Hp 1-1, whereas those with serum ferritin <6 micro g/L had viral loads less than one third (95% CI: 0.13-0.53, p =.013) that of women with serum ferritin >24 micro g/L. Viral loads were also higher in women enrolled in the early rainy season compared with the dry season, in gravidae 4+ compared with gravidae 1 through 3, and in those with moderately elevated compared with low serum alpha(1)-antichymotrypsin, but neither age, gestational age, serum folate, serum retinol, nor serum beta-carotene were predictors.


CONCLUSIONS
Storage iron, Hp 2-2, and elevated ACT are independent positive predictors of HIV-1 viral load. The positive relationship between serum ferritin and viral load was not the result of an acute phase response or iron accumulation with advanced HIV infection. A possible detrimental role of iron in HIV infection would have serious public health implications.
Friis
Henrik
H
Department of Human Nutrition, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark. h.friis@pubhealth.ku.dk
Gomo
Exnevia
E
Nyazema
Norman
N
Ndhlovu
Patricia
P
Krarup
Henrik
H
Madsen
Poul H
PH
Michaelsen
Kim F
KF
D005260:Female; D005293:Ferritins / Q000097:blood; D005492:Folic Acid / Q000097:blood; D015658:HIV Infections / Q000097:blood* / Q000235:genetics / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D007501:Iron / Q000097:blood*; D018977:Micronutrients / Q000097:blood; D010641:Phenotype; D011247:Pregnancy; D019562:Viral Load; D014801:Vitamin A / Q000097:blood; D015030:Zimbabwe; D000514:alpha 1-Antichymotrypsin / Q000097:blood; D019207:beta Carotene / Q000097:blood
D006242:Haptoglobins; D018977:Micronutrients; D000514:alpha 1-Antichymotrypsin; D019207:beta Carotene; D014801:Vitamin A; D005293:Ferritins; D005492:Folic Acid; D007501:Iron