Patients infected with human immunodeficiency virus (HIV) have been shown to constitute as many as 36% of patients with ferritin levels. 1000 ng/mL in previous studies [7, 8], and such patients account for 55% of our patient population. Baseline serum ferritin levels seem to be higher in HIV-positive patients [9], and levels reflect the degree of immune activation [10]. Levels. 10,000 ng/mL have been advocated by some authors as being a highly specific marker for DH [11]. Subsequent reports have suggested that ferritin levels. 10,000 ng/mL should actually be interpreted as a nonspecific indicator of superimposed infection and should not be associated with a specific disease entity [6]. All patients for whom serum ferritin measurement was performed from

January 2009 through July 2010 at the Steve Biko Academic Hospital (Pretoria, South Africa) were evaluated. A total of 19 patients had ferritin levels. 10,000 ng/mL (Table 1). Histoplasmosis was not diagnosed in any of the patients, and disseminated infection due to Mycobacterium tuberculosis seemed to be the most common infectious cause of elevated ferritin levels, accounting for 42% of all cases. Hyperferritinemia has been strongly associated with the presence of hemophagocytic syndrome [5, 12], although this phenomenon was not directly demonstrated in any of our clinical cases [5, 12]. We therefore concluded that, in our clinical setting, disseminated tuberculosis was the most important cause of severe hyperferritinemia, especially among HIV-positive patients.