Pathogenesis and pathophysiology of anemia in HIV infection

Abstract

Anemia occurs frequently among patients seropositive for human immunodeficiency virus (HIV), but its multifactorial origin complicates its differential diagnosis and adequate treatment. In addition, the etiology of anemia in HIV infection often remains unclear. In recent years several attempts have been undertaken to elucidate the mechanisms leading to HIV-associated anemia. Direct infection of erythroid progenitors has been discussed, but could not be proven. Furthermore, soluble factors like HIV proteins and cytokines have been suggested to inhibit growth of hematopietic cells in the bone marrow of HIV-infected patients. However, so far no statements can be made whether these factors are directly involved in myelosuppression or mediate their effect by inhibiting growth-factor synthesis. Opportunistic complications represent the underlying cause for anemia in a large number of HIV-infected patients. Next to this rather obvious reason for anemia, iatrogenic anemia induced by myelosuppressive drugs is also very common. It is of note, however, that modern dosages of < 600 mg zidovudine (ZDV) daily rarely cause anemia. Instead, other drugs that can induce anemia itself or by enhancing ZDV plasma concentrations must be considered important contributing factors. Deficiency of vitamin B12, folate and iron are frequently reported in HIV patients. However, specific investigations revealed appropriate storage amounts of these micronutrients. Supplementation may be beneficial in some patients, but often fails to reverse anemia in this population. In anemic HIV patients reticulocytopenia is a consistent finding. Additionally, inadequately low endogenous erythropoietin concentrations have been repeatedly reported. Thus, it is speculated that a blunted erythropoietin feedback mechanism contributes substantially to the pathogenesis of anemia in HIV patients.

Human immunodeficiency virus seropositivity and malaria as risk factors for third-trimester anemia in asymptomatic pregnant women in western Kenya.

“…The need for more frequent doses of sulfadoxine-pyrimethamine to prevent malaria in HIV-seropositive pregnant women, the concern that iron supplementation may be less useful in the presence of HIV infection, and the reported beneficial effects of multivitamin supplementation among HIV-seropositive pregnant women on Tcell counts points to the need for further evaluation of prevention strategies in areas of high HIV prevalence. 25,[43][44][45][46][47] This study confirms the importance of anemia in late pregnancy as a common problem in sub-Saharan Africa. In this study, anemia was associated with malaria parasitemia in first and second pregnancies.…”

Assessment of iron status using plasma transferrin receptor in pregnant women with and without human immunodeficiency virus infection in Malawi

“…Among anemic women seen in antenatal clinics in Dar-es-Salaam, Tanzania, iron de®-ciency and malaria were the two leading causes of anemia (Massawe et al, 1999). During HIV infection, the etiology of anemia is often dif®cult to determine, as HIV infection itself, malnutrition, malignancies, infections and hemolysis have all been identi®ed as factors which may contribute to anemia (Kreuzer & Rockstroh, 1997). Malaria is endemic in the study population, and a limitation of this study is that blood smears were not taken in all women to assess possible malaria parasitemia.…”

Determinants of Anemia Among Human Immunodeficiency Virus-Positive Adults at Care and Treatment Clinics in Dar es Salaam, Tanzania

“…9 The most obvious cause of anemia is blood loss, which may be associated with opportunistic complications such as neoplastic disease or gastrointestinal lesions that accompany Cytomegalovirus infection. 9,10 Other mechanisms including nutritional deficiencies, genetic disorders, and anemia due to chronic diseases are also important in this setting.…”