Inadequate PTH Response to Hypocalcemia in People Living with HIV.

BACKGROUND: Small experimental studies suggest that PTH-secretion following hypocalcemia might be blunted in people living with HIV. OBJECTIVE: The aim of the study was to estimate the frequency of inadequately low concentrations of parathyroid hormone in the presence of hypocalcemia in people living with HIV. METHODS: This was a retrospective study that was conducted among PLWH enrolled in the ongoing ArcHIV study between 2016 and 2017. PLWH with routine measurements for both calcium and parathyroid hormone levels were included in this analysis. The proportion of patients with a combination of low levels of both calcium and parathyroid hormone was the primary endpoint of this analysis. RESULT: 496 PLWH were included (mean age 47.1 (± 10.2) years, 393 (79.2 %) men). In 14 (2.8 %) PLWH, low calcium levels with low levels of PTH were observed in the assessment conducted in both years. Undergoing a tenofovir disoproxil-containing treatment in both years was the only explanatory variable significantly associated with inadequately low levels of PTH in the presence of hypocalcemia in both years (OR 4.3 [CI95: 1.4; 16.0]). CONCLUSION: The combination of low levels of both calcium and PTH was found more frequent in our study sample when compared to what is expected from the general population. Interestingly, undergoing a tenofovir disoproxil-containing therapy was associated with this combination throughout both the years.

Humoral response to SARS-CoV-2 vaccines in people living with HIV.

PURPOSE: To describe the humoral immune response to COVID-19 vaccines in people living with HIV and identify factors associated with the magnitude of anti-SARS-CoV-2 antibody concentrations. METHODS: Retrospective analysis of electronic patient files in a big single HIV center in Munich, Germany. Non-parametric methods were used for descriptive and comparative statistics. Generalized linear models were used to analyze associations of general and HIV-specific variables with anti-SARS-CoV-2 antibody concentrations after standard vaccination. RESULT: Overall, 665 people living with HIV were included into the analysis (median age: 53 [IQR: 43; 59]), 560 [84.2%] males). Median concentration of anti-SARS-CoV-2-antibodies was 1400 (IQR 664; 2130) BAU/mL. In 18 (2.7%) subjects, antibody concentrations below the threshold of 34 BAU/mL were found. Among PLWH with CD4 cell count < 200 cells/µL, median anti-SARS-CoV-2-Abs were 197 (IQR 44.6; 537.2) as compared to 1420 (IQR 687; 2216) for the group ≥ 200 cells/µL (p < 0.001). In a cumulative logit model, a vaccination scheme including an mRNA vaccine [OR: 4.64 (3.58; 6.02)], being female [OR: 2.14 (1.76; 2.61)], and having higher CD4 cells [OR per 100 cells/µL: 1.06 (1.04; 1.08)] were significantly associated with anti-SARS-CoV-2 antibody concentrations in higher quartiles, when adjusted for the time after vaccination. CONCLUSION: We found a robust antibody response in people living with HIV undergoing standard vaccination against SARS-CoV-2. mRNA-containing vaccination schemes, being female, and having a higher CD4 cell count was associated with a higher concentration of antibodies in people living with HIV in our study sample. Particularly in the subgroup with CD4 cell counts < 200 cells/µL, antibody response was poor.

Monthly or Weekly Supplementation with Cholecalciferol 20,000 IU in People Living with HIV: Results from a Nested Cohort Study.

BACKGROUND: There is still considerable uncertainty in handling vitamin D deficiency in people living with HIV (PLWH), due to a lack of comparative data and the wide range of recommended daily intake. Nondaily supplementation might be preferred in many PLWH, but recommendation on dosing has not been established. We aimed to compare the efficacy of weekly versus monthly supplementation with cholecalciferol 20,000 IU in a group of PLWH with vitamin D deficiency in Western Europe. STUDY DESIGN: Longitudinal, retrospective nested cohort study of PLWH from two large clinical care centers in Munich, Germany. RESULTS: Of 307 patients with vitamin D deficiency, 124 patients received vitamin D supplementation (weekly supplementation in 84 (67.7%)). 46.4% and 22.5% of patients achieved 25(OH)D levels ≥30 ng/mL after 12 months of weekly and monthly supplementation with cholecalciferol 20,000 IU, respectively (p=0.011). Dosing interval as well as 25(OH)D baseline levels >15 ng/mL were associated with the normalization of 25(OH)D. CONCLUSION: A higher rate of 25(OH)D level normalization can be achieved via weekly supplementation. For several PLWH, even a weekly dose of cholecalciferol 20,000 IU might not be adequate to maintain 25(OH)D levels >30 ng/mL without an initial "loading" dose. The response to supplementation is poorly predictable at an individual level.

Secondary Hyperparathyroidism in HIV-Infected Patients in Central Europe.

Secondary hyperparathyroidism (sHPT) might be a contributor to increased risk of osteoporosis in adult HIV patients but there is little data available on this issue in this particular population. The aim of the study was to investigate the prevalence of sHPT in an HIV-infected population with normal kidney function and to evaluate its risk factors in HIV patients. This cross-sectional study was carried out in a single HIV center in Germany using routine data from patients with normal kidney function attending the clinic between January 1st and December 31st, 2016. In total, 1263 patients were included [998 (79.0%) male, median age 48 (IQR 38-54) years]. In 214 patients (16.9%) elevated PTH levels with low or normal calcium levels were found. Multivariate logistic regression modeling showed significant associations with elevated PTH for African ethnicity [OR: 2.12 (95% CI: 1.42-3.16); p<0.001], low 25-hydroxyvitamin D levels [OR: 1.82 (95% CI: 1.32-2.51); p<0.001], low calcium levels [OR 1.69 (95% CI: 1.22-2.33); p=0.001], and use of tenofovir disoproxil fumarate [OR 2.33 (95% CI: 1.62-3.36); p<0.001]. Additional to common risk factors like vitamin D insufficiency and hypocalcemia, we found a significant association between the use of TDF and sHPT. Prospective data are needed to ascertain whether PTH-mediated bone loss is the underlying mechanism of TDF bone-toxicity. Additional screening of PTH even in HIV-infected patients with normal or low calcium levels may help to identify patients at increased risk of bone mineral density loss.

Tenofovir Disoproxil Fumarate Is Associated with a Set-Point Variation in the Calcium-Parathyroid Hormone-Vitamin D Axis: Results from a German Cohort.

BACKGROUND: Higher levels of parathyroid hormone have been associated with the use of tenofovir disoproxil fumarate (TDF) in people with and without HIV infection. Yet, alterations in calcium levels have never been elucidated in detail. OBJECTIVE: To compare the association of parathyroid hormone with serum calcium levels and other markers of calcium and bone metabolism in people living with HIV on TDF- and non-TDF-containing antiretroviral therapy. PATIENTS AND METHODS: A retrospective single center cohort study in Munich, Germany. Median and interquartile ranges and absolute and relative frequencies were used to describe continuous and categorical variables, respectively. The Mann-Whitney U test and chi2-test were used for comparisons. Multivariate median regression was performed in a stepwise backward approach. RESULTS: 1,002 patients were included (786 (78.4%) male; median age 48 (40-55) years). 564 patients (56.3%) had a TDF-containing ART regimen. PTH concentrations were 46.9 (33.0-64.7) pg/mL and 35.2 (26.4-55.4) pg/mL (P=0.001), 43.3 (30.8-59.8) pg/mL and 31.8 (22.3-49.6) pg/mL (P < 0.001), 46.1 (29.5-65.4) pg/mL and 33.4 (22.6-50.1) pg/mL (P < 0.001), and 37.8 (25.3-57.9) pg/mL and 33.8 (20.1-45.3) pg/mL (P=0.012) within the first, second, third, and fourth quartile of corrected calcium levels for patients with and without TDF-containing ART, respectively. In multivariate median regression, PTH concentration was significantly associated with Cacorr. (-32.2 (-49.8 to -14.8); P < 0.001), female sex (5.2 (1.2-9.2); P=0.010), 25(OH)D (-0.4 (-0.5 to -0.3); P < 0.001), and TDF-use (9.2 (6.0-12.5); P < 0.001). DISCUSSION: Higher levels of PTH seem to be needed to maintain normal calcium levels in PLWH on TDF-containing ART compared to non-TDF-containing ART. Optimal concentrations for 25-hydroxy vitamin D and calcium might therefore be different in people using TDF than expected from general populations but also people living with HIV with non-TDF-containing antiretroviral therapy. This might require different supplementation strategies but warrants further investigation.

Patterns of vitamin D, parathyroid hormone and c-terminal telopeptide of collagen type 1 in Caucasian and African descent HIV-infected populations in Central Europe.

Risk factors for bone loss in HIV patients might differ or have a different impact in African descent compared to Caucasian populations. The aim of the paper is to analyze the relevance of risk factors on surrogate markers of bone metabolism in HIV-infected African descent and Caucasian patients. This is a cross-sectional study in a single HIV-specialized research and clinical care center in Munich, Germany. We included 889 patients in the study, among them 771 Caucasians (86.7%). Only in Caucasians lower vitamin D levels [OR: 2.5 (95CI: 1.6-3.7)], lower calcium levels [OR: 1.8 (1.2-2.8)], and the use of tenofovir disoproxil fumarate [OR: 2.8 (1.8-4.4)] were significantly associated with elevated PTH in multivariate analysis. Likewise, only in Caucasians elevated PTH was significantly associated with elevated markers of c-terminal telopeptides of collagen type 1 (ß-CTX) [OR: 1.7 (1.0-3.0)]. Effects of traditional risk factors for secondary hyperparathyroidism and increased markers of bone turn-over seem to be less distinct in African descent HIV patients. The clinical impact and generalizability of this finding as well as the significance of vitamin D supplementation in African descent patients therefore warrants further investigation.

Dolutegravir monotherapy as treatment de-escalation in HIV-infected adults with virological control: DoluMono cohort results.

BACKGROUND: The potential toxicity of long-term antiretroviral therapy (ART) requires ongoing investigation of novel strategies for treatment of HIV-infected patients. Monotherapy with the integrase inhibitor (INSTI) dolutegravir (DTG) may offer a favourable safety profile. Additionally, DTG has a high barrier of resistance, crucial for successful maintenance of virological control. However, published data is sparse. METHODS: Retrospective, single-centre cohort study. We enrolled patients on suppressive ART who were switched to DTG monotherapy in routine clinical practice and fulfilled the following inclusion criteria: HIV RNA level <50 copies/ml for ≥6 months at time of switch (one blip <200 copies/ml with re-suppression accepted), no known INSTI resistance or prior INSTI failure, no replicative HBV infection and no history of AIDS. RESULTS: We identified 31 patients with 24-weeks of follow-up data. Previous ART included a non-nucleoside reverse transcriptase inhibitor, a boosted protease inhibitor or an INSTI in 32%, 6% and 61% of patients, respectively. At week 24, HIV RNA remained <50 copies/ml in all but two patients (94%). One patient chose to discontinue DTG monotherapy and another developed confirmed virological failure (HIV RNA 538 copies/ml) with new INSTI mutations (Q148H/G140S). Immune status and renal and metabolic function showed no statistically significant changes, apart from a significant decrease in gamma-glutamyl transferase. CONCLUSIONS: De-escalating to DTG monotherapy in selected patients might be a safe and feasible option. However, in one case evolution of INSTI resistance was observed. Further studies should assess particular risk factors for DTG monotherapy failure. In the meanwhile, caution is warranted.