A. Patrick MacPhail

The ratio of serum transferrin receptor and serum ferritin in the diagnosis of iron status

Laboratory tests used in the diagnosis of iron status lack specificity in defining iron deficiency anaemia (IDA) and anaemia of inflammation (AI). The serum transferrin receptor (sTfR) may provide more information in this regard. The iron status of 561 pre‐school children was determined and classified using the conventional measurements. The value of the concentration of sTfR, the ratio of sTfR (µg/ml) to LogSF (µg/l) (TfR‐Index), and the Log of the ratio of sTfR (µg/l) to SF (µg/l) − (LogTfR:Fer ratio), in the classification of the iron status were determined by comparing their distributions across the classification of iron status. Although there were significant differences in sTfR and TfR‐Index across the categories of iron status, there was considerable overlap. All subjects with iron deficiency had LogTfR:Fer ratio > 2·55, whereas in all subjects classified as AI it was < 2·55, thus clearly separating the two. The LogTfR:Fer ratio was not able to exclude IDA in the presence of inflammation. However, in cases of combined IDA and AI the LogTfR:Fer ratio was < 2·55 but increased to > 2·55 after resolution of the inflammation. This novel method of calculating the LogTfR:Fer ratio may provide a more precise classification of the iron status of children.

Cohort Profile: The Themba Lethu Clinical Cohort, Johannesburg, South Africa

The Themba Lethu Clinical Cohort was established in 2004 to allow large patient-level analyses from a single HIV treatment site to evaluate National Treatment Guidelines, answer questions of national and international policy relevance and to combine an economic and epidemiologic focus on HIV research. The current objectives of the Themba Lethu Clinical Cohort analyses are to: (i) provide cohort-level information on the outcomes of HIV treatment; (ii) evaluate aspects of HIV care and treatment that have policy relevance; (iii) evaluate the cost and cost-effectiveness of different approaches to HIV care and treatment; and (iv) provide a platform for studies on improving HIV care and treatment. Since 2004, Themba Lethu Clinic has enrolled approximately 30,000 HIV-positive patients into its HIV care and treatment programme, over 21,000 of whom have received anti-retroviral therapy since being enrolled. Patients on treatment are typically seen at least every 3 months with laboratory monitoring every 6 months to 1 year. The data collected include demographics, clinical visit data, laboratory data, medication history and clinical diagnoses. Requests for collaborations on analyses can be submitted to our data centre.

Gender differences in mortality and CD4 count response among virally suppressed HIV-positive patients.

BACKGROUND Treatment outcomes for antiretroviral therapy (ART) patients may vary by gender, but estimates from current evidence may be confounded by disease stage and adherence. We investigated the gender differences in treatment response among HIV-positive patients virally suppressed within 6 months of treatment initiation. METHODS We analyzed data from 7,354 patients initiating ART between April 2004 and April 2010 at Themba Lethu Clinic, a large urban public sector treatment facility in South Africa. We estimated the relations among gender, mortality, and mean CD4 response in HIV-infected adults virally suppressed within 6 months of treatment initiation and used inverse probability of treatment weights to correct estimates for loss to follow-up. RESULTS Male patients had a 20% greater risk of death at both 24 months and 36 months of follow-up compared to females. Older patients and those with a low hemoglobin level or low body mass index (BMI) were at increased risk of mortality throughout follow-up. Men gained fewer CD4 cells after treatment initiation than did women. The mean differences in CD4 count gains made by women and men between baseline and 12, 24, and 36 months were 28.2 cells/mm(3) (95% confidence interval [CI] 22.2-34.3), 60.8 cells/mm(3) (95% CI 71.1-50.5 cells/mm(3)), and 83.0 cells/mm(3) (95% CI 97.1-68.8 cells/mm(3)), respectively. Additionally, patients with a current detectable viral load (>400 copies/mL) and older patients had a lower mean CD4 increase at the same time points. CONCLUSIONS In this initially virally suppressed population, women showed consistently better immune response to treatment than did men. Promoting earlier uptake of HIV treatment among men may improve their immunologic outcomes.

Ferroportin (Q248H) mutations in African families with dietary iron overload

Background:  Dietary iron overload found in sub‐Saharan Africa might be caused by an interaction between dietary iron and an iron‐loading gene. Caucasian people with ferroportin gene mutations have iron overload histologically similar to that found in African patients with iron overload. Ferroportin is also implicated in the hypoferremic response to inflammation. The prevalence of the ferroportin Q248H mutation, unique to African people, and its association with dietary iron overload, mean cell volume (MCV) and C‐reactive protein (CRP) were examined in 19 southern African families.

Poorer ART Outcomes with Increasing Age at a Large Public Sector HIV Clinic in Johannesburg, South Africa

Background: As the current HIV-positive population ages, the absolute number of patients >50 years on treatment is increasing. Methods: We analyze the differences in treatment outcomes by age category (18-29, 30-39, 40-49, 50-59, and ≥60) among 9139 HIV-positive adults initiating ART in South Africa. Results: The adjusted hazard ratios (HRs) for all-cause mortality increased with increasing age, with the strongest association in the first 12 months of follow-up among patients 50 to 59 years (HR 1.67; 95% confidence interval [CI]: 1.24-2.23) versus those <30 years. However, patients 50 to 59 years were less likely to be lost during 24 months on antiretroviral therapy ([ART] HR 0.75; 95% CI: 0.59-0.94) versus patients <30 years. By 6 and 12 months on treatment, older patients were less likely to increase their CD4 count by ≥50 cells/mm3. Conclusion: Although older patients are at higher risk of mortality and have poorer immunological responses than their younger counterparts, they are more likely to adhere to care and treatment in the first 24 months on ART.

Prevalence and predictors of kaposi sarcoma herpes virus seropositivity: a cross-sectional analysis of HIV-infected adults initiating ART in Johannesburg South Africa.

BackgroundKaposi sarcoma (KS) is the most common AIDS-defining tumour in HIV-infected individuals in Africa. Kaposi sarcoma herpes virus (KSHV) infection precedes development of KS. KSHV co-infection may be associated with worse outcomes in HIV disease and elevated KSHV viral load may be an early marker for advanced HIV disease among untreated patients. We examined the prevalence of KSHV among adults initiating antiretroviral therapy (ART) and compared immunological, demographic and clinical factors between patients seropositive and seronegative for KSHV.ResultsWe analyzed cross-sectional data collected from 404 HIV-infected treatment-naïve adults initiating ART at the Themba Lethu Clinic, Johannesburg, South Africa between November 2008 and March 2009. Subjects were screened at ART initiation for antibodies to KSHV lytic K8.1 and latent Orf73 antigens. Seropositivity to KSHV was defined as positive to either lytic KSHV K8.1 or latent KSHV Orf73 antibodies. KSHV viremia was determined by quantitative PCR and CD3, 4 and 8 lymphocyte counts were determined with flow cytometry. Of the 404 participants, 193 (48%) tested positive for KSHV at ART initiation; with 76 (39%) reactive to lytic K8.1, 35 (18%) to latent Orf73 and 82 (42%) to both. One individual presented with clinical KS at ART initiation. The KSHV infected group was similar to those without KSHV in terms of age, race, gender, ethnicity, smoking and alcohol use. KSHV infected individuals presented with slightly higher median CD3 (817 vs. 726 cells/mm3) and CD4 (90 vs. 80 cells/mm3) counts than KSHV negative subjects. We found no associations between KSHV seropositivity and body mass index, tuberculosis status, WHO stage, HIV RNA levels, full blood count or liver function tests at initiation. Those with detectable KSHV viremia (n = 19), however, appeared to present with signs of more advanced HIV disease including anemia and WHO stage 3 or 4 defining conditions compared to those in whom the virus was undetectable.ConclusionsWe demonstrate a high prevalence of KSHV among HIV-infected adults initiating ART in a large urban public-sector HIV clinic. KSHV viremia but not KSHV seropositivity may be associated with markers of advanced HIV disease.

Anemia among HIV-Infected Patients Initiating Antiretroviral Therapy in South Africa: Improvement in Hemoglobin regardless of Degree of Immunosuppression and the Initiating ART Regimen

Among those with HIV, anemia is a strong risk factor for disease progression and death independent of CD4 count and viral load. Understanding the role of anemia in HIV treatment is critical to developing strategies to reduce morbidity and mortality. We conducted a prospective analysis among 10,259 HIV-infected adults initiating first-line ART between April 2004 and August 2009 in Johannesburg, South Africa. The prevalence of anemia at ART initiation was 25.8%. Mean hemoglobin increased independent of baseline CD4. Females, lower BMI, WHO stage III/IV, lower CD4 count, and zidovudine use were associated with increased risk of developing anemia during follow-up. After initiation of ART, hemoglobin improved, regardless of regimen type and the degree of immunosuppression. Between 0 and 6 months on ART, the magnitude of hemoglobin increase was linearly related to CD4 count. However, between 6 and 24 months on ART, hemoglobin levels showed a sustained overall increase, the magnitude of which was similar regardless of baseline CD4 level. This increase in hemoglobin was seen even among patients on zidovudine containing regimens. Since low hemoglobin is an established adverse prognostic marker, prompt identification of anemia may result in improved morbidity and mortality of patients initiating ART.

Kaposi sarcoma-associated herpes virus and response to antiretroviral therapy: a prospective study of HIV-infected adults

Background: The possible impact of coinfection with the Kaposi sarcoma–associated herpes virus (KSHV) on the response to antiretroviral therapy (ART) is unknown. Prospective studies are rare, particularly in Africa. Methods: We enrolled a prospective cohort of HIV-infected adults initiating ART in Johannesburg, South Africa. The subjects were defined as seropositive to KSHV if they were reactive to either KSHV lytic K8.1 or latent Orf73 antigen or to both. The subjects were followed from ART initiation until 18 months of treatment. HIV viral load and CD4 counts were tested 6 monthly. Linear generalized estimating and log-binomial regression models were used to estimate the effect of KSHV infection on immunologic recovery and response and HIV viral load suppression within 18 months after ART initiation. Results: Three hundred eighty-five subjects initiating ART from November 2008 to March 2009 were considered to be eligible including 184 (48%) KSHV+. The KSHV+ group was similar to the KSHV− in terms of age, gender, initiating CD4 count, body mass index, tuberculosis, and hemoglobin levels. The KSHV+ group gained a similar number of cells at 6 [difference of 10 cells per cubic millimeter, 95% confidence interval (CI): −11 to 31], 12 (3 cells per cubic millimeter, 95% CI: −19 to 25), and 18 months (24 cells per cubic millimeter, 95% CI: −13 to 61) compared with that gained by the KSHV− group. Adjusted relative risk of failure to suppress viral load to <400 copies per milliliter (1.03; 95% CI: 0.90 to 1.17) were similar for KSHV+ and KSHV− by 6 months on treatment. Conclusions: In a population with a high KSHV prevalence, HIV-positive adults coinfected with KSHV achieved similar immunologic and virologic responses to ART early after treatment initiation compared with those with KSHV−.

The feasibility of using screening criteria to reduce clinic visits for stable patients on antiretroviral therapy in South Africa.

Objectives:South African HIV care providers are exploring ways to reduce the intensity of patient visits while maintaining high quality of care. We used routinely collected data to model whether a simple screening tool could identify stable patients who would not need to see a doctor during a scheduled medical visit. Design:We identified stable and nonstable visits from January 2007 to September 2011 at a large HIV clinic in Johannesburg, SA. Stable medical visits were defined as having all of the following: stable CD4 count, undetectable viral load, stable weight, not pregnant, no comorbidity, no regimen change within three months, and normal laboratory results for hemoglobin, alanine aminotransferase, and creatinine clearance. Methods:We assessed the sensitivity and specificity of nonstable visits at predicting indicators of disease progression or needing additional care: (1) ART regimen change and (2) follow-up visits in <2 and <4 weeks from previous visit. Results:Stable visits had a sensitivity of 88.9% (95% confidence interval: 88.2 to 89.7) and a specificity of 44.8% (44.5 to 44.1) at predicting ART therapy changes, and a sensitivity of 72.6% (71.8 to 73.4) and specificity of 45.1% (44.8 to 45.4) for predicting a follow-up visit interval of <2 weeks and similar results for predicting a follow-up visit interval of <4 weeks. Conclusions:Our retrospective analysis suggests an approach to potentially reduce the number of medical visits while missing few visits in which changes in regimen or additional care would be needed. Evaluation of our criteria in a primary care setting is needed to determine whether they could safely reduce visits.

Basal endocrine status in African dietary iron overload.

Endocrine disturbances, notably diabetes, have been well described as a complication of iron overload due to hereditary hemochromatosis and β-thalassemia. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has also been well documented. The pattern of iron loading in African iron overload with saturated transferrin is similar to that seen in hereditary hemochromatosis. In addition, many symptoms ascribed to pituitary dysfunction are common to both conditions. The present study was undertaken to assess whether a similar pattern of endocrine dysfunction occurs in African iron overload. Thirty subjects with African iron overload and transferrin saturation >50%, plus 30 age and sex matched normal controls were studied. An iron profile, fasting plasma glucose, cortisol, DHEA-S, LH, FSH, growth hormone, prolactin, TSH, and FT4 levels were measured in all 60 subjects as well as testosterone in the males and estradiol in the females. Iron loading in the subjects with increased transferrin saturation ranged from moderate to severe. No significant differences were found in the mean testosterone, estradiol, LH, DHEA-S, growth hormone, prolactin, or TSH levels between the subjects and normal controls. In female subjects, although within the normal range, the mean FSH level was significantly higher, probably due to their being somewhat older and in a more advanced stage of menopause than the control females. Mean cortisol concentrations were increased in both genders in the patient group, significantly so in the females; however, values were within the reference range. We conclude therefore that there appears to be no major impairment of endocrine function in the basal state in African iron overload subjects with moderate to severe degrees of iron loading.