Advancing HIV Drug Resistance Technologies and Strategies: Insights from South Africa's Experience and Future Directions for Resource-Limited Settings

Monitoring of HIV drug resistance (HIVDR) remains critical for ensuring countries attain and sustain the global goals for ending HIV as a public health threat by 2030. On an individual patient level, drug resistance results assist in ensuring unnecessary treatment switches are avoided and subsequent regimens are tailored on a case-by-case basis, should resistance be detected. Although there is a disparity in access to HIVDR testing in high-income countries compared to low- and middle-income countries (LMICS), more LMICs have now included HIVDR testing for individual patient management in some groups of patients. In this review, we describe different strategies for surveillance as well as where HIVDR testing can be implemented for individual patient management. In addition, we briefly review available technologies for HIVDR testing in LMICs, including Sanger sequencing, next-generation sequencing, and some point-of-care options. Finally, we describe how South Africa has implemented HIVDR testing in the public sector.

Resistance is common in paediatric patients failing ART in South Africa

BACKGROUND

Minimal data exist on HIV drug resistance patterns and prevalence among paediatric patients failing ART in resource-limited settings. We assessed levels of HIV drug resistance in children with virological failure.

METHODS

This cross-sectional study, performed from March 2017 to March 2019 in South Africa, enrolled HIV-positive children aged ≤19 years, receiving ART through public health facilities with recent evidence suggestive of virological failure (at least one viral load ≥1000 copies/mL), across 45 randomly selected high-volume clinics from all nine provinces. Resistance genotyping was performed using next-generation sequencing technologies. Descriptive analysis taking into account survey design was used to determine outcomes.

RESULTS

Among 899 participants enrolled, the adjusted proportion of HIV drug resistance among children with virological failure was 87.5% (95% CI 83.0%-90.9%). Resistance to NNRTIs was detected in 77.4% (95% CI 72.5%-81.7%) of participants, and resistance to NRTIs in 69.5% (95% CI 62.9%-75.4%) of participants. Overall, resistance to PIs was detected in 7.7% (95% CI 4.4%-13.0%) of children.

CONCLUSIONS

HIV drug resistance was highly prevalent in paediatric patients failing ART in South Africa, with 9 in 10 patients harbouring resistance to NNRTIs and/or NRTIs. PI-based regimens are predicted to be highly efficacious in achieving virological suppression amongst patients failing NNRTI-based regimens. Scaling up resistance testing amongst patients would facilitate access to second- and third-line regimens in South Africa.

HIV drug resistance profile in South Africa: Findings and implications from the 2017 national HIV household survey

BACKGROUND

HIV drug resistance (HIVDR) testing was included in the 2017 South African national HIV household survey. We describe the prevalence of HIVDR by drug class, age, sex and antiretroviral drugs (ARV) status.

METHODS

Dried blood were spots tested for HIV, with Viral load (VL), exposure to ARVs and HIVDR testing among those HIV positive. HIVDR testing was conducted on samples with VL ≥1000 copies/ml using Next Generation Sequencing. Weighted percentages of HIVDR are reported.

RESULTS

697/1,105 (63%) of HIV positive samples were sequenced. HIVDR was detected in samples from 200 respondents (27.4% (95% confidence interval (CI) 22.8-32.6)). Among these 130 (18.9% (95% CI 14.8-23.8)), had resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) only, 63 (7.8% (95% CI 5.6-10.9)) resistance to NNRTIs and nucleoside reverse transcriptase inhibitors, and 3 (0.5% (95% CI 0.1-2.1)) resistance to protease inhibitors. Sixty-five (55.7% (95% CI 42.6-67.9) of ARV-positive samples had HIVDR compared to 112 (22.8% (95% CI 17.7-28.7)), in ARV-negative samples. HIVDR was found in 75.6% (95% CI 59.2-87.3), n = 27, samples from respondents who reported ARV use but tested ARV-negative, and in 15.3% (95% CI 6.3-32.8), n = 7, respondents who reported no ARV use and tested ARV-negative. There were no significant age and sex differences in HIVDR.

CONCLUSION

27% of virally unsuppressed respondents had HIVDR, increasing to 75% among those who had discontinued ARV. Our findings support strengthening first-line ARV regimens by including drugs with a higher resistance barrier and treatment adherence strategies, and close monitoring of HIVDR.

High levels of HIV drug resistance among adults failing second-line antiretroviral therapy in Namibia

To support optimal third-line antiretroviral therapy (ART) selection in Namibia, we investigated the prevalence of HIV drug resistance (HIVDR) at time of failure of second-line ART. A cross-sectional study was conducted between August 2016 and February 2017. HIV-infected people ≥15 years of age with confirmed virological failure while receiving ritonavir-boosted protease inhibitor (PI/r)-based second-line ART were identified at 15 high-volume ART clinics representing over >70% of the total population receiving second-line ART. HIVDR genotyping of dried blood spots obtained from these individuals was performed using standard population sequencing methods. The Stanford HIVDR algorithm was used to identify sequences with predicted resistance; genotypic susceptibility scores for potential third-line regimens were calculated. Two hundred thirty-eight individuals were enrolled; 57.6% were female. The median age and duration on PI/r-based ART at time of enrolment were 37 years and 3.46 years, respectively. 97.5% received lopinavir/ritonavir-based regimens. The prevalence of nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), and PI/r resistance was 50.6%, 63.1%, and 13.1%, respectively. No significant association was observed between HIVDR prevalence and age or sex. This study demonstrates high levels of NRTI and NNRTI resistance and moderate levels of PI resistance in people receiving PI/r-based second-line ART in Namibia. Findings underscore the need for objective and inexpensive measures of adherence to identify those in need of intensive adherence counselling, routine viral load monitoring to promptly detect virological failure, and HIVDR genotyping to optimize selection of third-line drugs in Namibia.

Lower frequency of NPM1 and FLT3-ITD mutations in a South African adult de novo AML cohort

INTRODUCTION

Acute myeloid leukemia (AML) is a heterogeneous clonal disorder of hemopoietic progenitor cells diagnosed in individuals of any age, but with a median age of 67 years at presentation in adults. Assessment of the mutation status of nucleophosmin protein-1 (NPM1) and FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) is essential for the prognosis, and treatment of AML.

METHODS

A total of 160 de novo AML cases, both cytogenetically normal and abnormal, were analyzed for the presence of NPM1 and FLT3-ITD mutations, and the results assessed in conjunction with epidemiological, clinical, and laboratory findings.

RESULTS

Nucleophosmin protein-1 mutations were found in 7.5%, while FLT3-ITD was present in 12% of these cases. Both of these were lower than expected. The median age at diagnosis of AML was 41 years, and for the FLT3-ITD only cases, median age was 33 years; these ages were younger than expected.

CONCLUSION

The lower reported frequencies and younger median age at diagnosis of AML and these specific mutations may be contributed to by a number of factors including effects of race on age of presentation, inclusion of patients diagnosed with de novo AML only, and a generally younger median age of the South African population.

[Selective laser trabeculoplasty]

The prospective clinical study of the selective laser trabeculoplasty (SLT) by means the Coherent Selecta 7000 laser (wave length 532 nm) was conducted. Totally 108.7 +/- 18.3 laser non-overlapping spots (mean energy level 1.04 +/- 0.22 mJ) along the whole circle of the trabecular meshwork in the anterior chamber angle were applied. The study included 258 eyes of 146 patients (50 of them were men) with glaucoma. The mean age of the whole group was 55.9 +/- 13.7 years. The group of unsuccessfully treated patients (30 patients, 41 eyes) in whom the intraocular pressure (IOP) elevated from 23.2 +/- 3.7 mm Hg in 4.7% (measured 493 +/- 474 days after the treatment) during the follow up, was removed from the study. In the group with good response to the SLT, 116 patients (217 eyes) were evaluated 650 +/- 405 days after treatment. Before treatment, in this group the IOP was 23.9 +/- 3.0 mm Hg, at the end of the study the IOP was lowered by 4.5 +/- 2.9 mm Hg, in total by 18.6%. IOP decrease was more pronounced in patients with higher level of IOP at the beginning. Immediately after SLT, no significant rising of the IOP level was recorded. Selective laser trabeculoplasty preserves the integrity of the trabecular meshwork of the anterior chamber angle, and is a safe and clinically effective method of treatment of different forms of glaucoma and ocular hypertension.

[Refractive lensectomy with intraocular lens implantation in hypermetropia gravis]

The objective of the study was to evaluate the results of refractive lensectomy with implantation of an IOL in patients with hypermetropia gravis. The authors included in the group patients operated at the Ophthalmological Clinic in Hradec Králové between May 1995 and April 1997 with a refraction of +7.2 +/- 1.76 D and axial length of 19.91 +/- 1.23 mm. The mean value of IOL was 32 +/- 1.8 (+30.0 to +35.0 D). The group comprised 124 men and 23 women (range 21-67 years, mean age 45.8 +/- 10.5 years). From the total number of 94 eyes 22 were operated, while the patients were hospitalized, 72 were operated at the out-patient department. Visus of 6/12 and better with supplementary correction was achieved in 73 eyes, i.e. 77% during the last check up. Before operation thist was the case in 70 eyes, i.e. 75.3%. The mean refraction after operations was -0.25 +/- 1.05 D. Lensectomy in hypermetropia gravis with implantation of an intraocular lens is according to the achieved functional results a fully justified method for resolving the problem of severe far-sightedness.

[Implantation of intraocular lenses in myopia]

The objective of the investigation was to evaluate implantation of an intraocular lens in patients with cataract and myopia. Posterior chamber intraocular lenses (IOL)+15 D and lens with a length of the axis of 25.00 mm and more were implanted after ECCE or phacoemulsification in the year 1994 in 81 eyes of 71 patients with mean age of 69 years (range 45 - 81 years). The mean length of the axis was 27.05 mm +/- 1.49 mm, the mean value of the IOL was +11.2 +/- 2.83 diopters. Vision of 6/12 and better with supplementary correction was achieved in 62.7% of the eyes during the last check-up examination. The mean refraction value after surgery was -2.11 +/- 1.63 diopters with a range from +2.0 to -6.0 diopters. Surgery of cataract in myopia gravis with implantation of a posterior chamber intraocular lens is fully justified and makes it possible to achieve excellent functional results.

[Dynamics of retinal changes in relation to treatment of Waldenström's macroglobulinemia]

Authors document with the aid of fluorescent angiography of the retina pathological changes on the retina resulting from hyperviscous syndrome of Waldenstrom macroglobulinemia and their regulation after combined treatment with plasmapheresis and cytostatics.