Pancreatic INI1-deficient undifferentiated rhabdoid carcinoma achieves complete clinical response on gemcitabine and nab-paclitaxel following immediate progression on FOLFIRINOX: a case report

INTRODUCTION

INI1-deficient undifferentiated rhabdoid carcinoma is a rare pancreatic carcinoma for which the optimal treatment is unknown. Pancreatic ductal adenocarcinoma, the most common histology of pancreas cancer, is treated with combination chemotherapy in the advanced setting, a strategy supported by strong evidence in well powered studies. In patients with excellent performance status, first-line treatment usually consists of the three-drug regimen FOLFIRINOX, with the combination of gemcitabine with nab-paclitaxel, typically less toxic than the three-drug regimen, reserved for second-line therapy. Given the lack of published reports describing treatment outcomes for patients with rare forms of pancreatic cancer, the same treatment approach used for pancreatic ductal adenocarcinoma is typically employed.

OBSERVATION

This case describes a patient with metastatic pancreatic INI1-deficient undifferentiated rhabdoid carcinoma who was primarily resistant to FOLFIRINOX therapy but who then achieved an immediate, marked and sustained response to gemcitabine with nab-paclitaxel.

CONCLUSION

Given the lack of data informing on optimal management of INI1-deficient pancreatic undifferentiated rhabdoid carcinoma, and the exceptional response achieved by gemcitabine with nab-paclitaxel, this case report highlights a surprising and potentially informative anecdote. Additional studies are needed to confirm responses observed in this report which when taken together may strongly influence first-line therapy choice for this rare malignancy. Given the difficult in acquiring sufficient numbers of these rare histologies in any one institution, multi-institution collaboration in studying outcomes of rare pancreatic malignancies is likely essential.

Association of Viral Persistence and Atherosclerosis in Adults With Treated HIV Infection

IMPORTANCE

Persons living with HIV (PLWH) have increased risk for cardiovascular disease, and inflammation is thought to contribute to this excess risk. Production of HIV during otherwise effective antiretroviral therapy (ART) has been associated with inflammation.

OBJECTIVE

To determine whether higher levels of viral persistence are associated with atherosclerosis as assessed by changes in carotid artery intima-media thickness (IMT) over time.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, intima-media thickness, a validated marker of atherosclerosis, was assessed over time in a cohort of treated PLWH with viral suppression. Cell-associated HIV DNA and RNA and change in IMT, adjusted for demographics, cardiovascular risk factors, and HIV-related factors, were examined, as well as which factors were associated with viral persistence. One hundred fifty-two PLWH with undetectable viral loads for at least 6 months before study enrollment were recruited from HIV clinics affiliated with 2 hospitals in San Francisco, California, from January 1, 2003, to December 31, 2012. Data were analyzed from February 7, 2018, to May 12, 2020.

EXPOSURES

Cell-associated HIV RNA and DNA were measured using enriched CD4+ T cells from cryopreserved peripheral blood mononuclear cells.

MAIN OUTCOMES AND MEASURES

Carotid IMT was measured at baseline and the last visit, with a mean (SD) follow-up of 4.2 (2.7) years, using high-resolution B mode ultrasonography. The main study outcomes were baseline IMT, annual IMT progression, and incident plaque, defined as a focal region of carotid IMT of greater than 1.5 mm.

RESULTS

The analysis included 152 PLWH (140 [92.1%] male; median age, 48.5 [interquartile range {IQR}, 43.3-53.7] years). Older age, smoking, medications for hypertension, higher low-density lipoprotein levels, and higher interleukin 6 levels were associated with higher baseline mean IMT, whereas cell-associated HIV DNA (estimate, -0.07% [95% CI, -6.1% to 6.4%]; P = .98), and HIV RNA levels (estimate, -0.8% [95% CI, -5.9% to 4.4%]; P = .75) were not. Levels of HIV RNA (0.017 [95% CI, 0.000-0.034] mm/y; P = .047) and HIV DNA (0.022 [95% CI, 0.001-0.044] mm/y; P = .042) were significantly associated with annual carotid artery IMT progression in unadjusted models only. Both HIV RNA (incidence risk ratio [IRR], 3.05 [95% CI, 1.49-6.27] per IQR; P = .002) and HIV DNA (IRR, 3.15 [95% CI, 1.51-6.57] per IQR; P = .002) were significantly associated with incident plaque, which remained significant after adjusting for demographics, cardiovascular risk factors, and HIV-related factors (IRR for HIV RNA, 4.05 [95% CI, 1.44-11.36] per IQR [P = .008]; IRR for HIV DNA, 3.35 [95% CI, 1.22-9.19] per IQR [P = .02]). Higher C-reactive protein levels were associated with higher cell-associated HIV RNA (estimate, 20.7% [95% CI, 0.9%-44.4%] per doubling; P = .04), whereas higher soluble CD14 levels were associated with HIV DNA (estimate, 18.6% [95% CI, 3.5%-35.8%] per 10% increase; P = .01). Higher soluble CD163 levels were associated with a higher HIV RNA:DNA ratio (difference, 63.8% [95% CI, 3.5%-159.4%]; P = .04).

CONCLUSIONS AND RELEVANCE

These findings suggest that measurements of viral persistence in treated HIV disease are independently associated with incident carotid plaque development. The size and transcriptional activity of the HIV reservoir may be important contributors to HIV-associated atherosclerosis.

Carnitine Is Associated With Atherosclerotic Risk and Myocardial Infarction in HIV -Infected Adults

Background

People living with HIV (PLWH) have an increased risk of myocardial infarction (MI). Changes in the gut microbiota that occur with chronic HIV infection could play a role in HIV‐associated atherosclerosis. Choline, carnitine, betaine, and trimethylamine N‐oxide are small molecules that are, in part, metabolized or produced by the gut microbiome. We hypothesized that these metabolites would be associated with carotid artery intima‐media thickness and MI in PLWH.

Methods and Results

Carotid artery intima‐media thickness was measured at baseline and at a median interval of 4 years in 162 PLWH from the SCOPE (Study of the Consequences of the Protease Inhibitor Era) cohort in San Francisco, CA. Separately, 105 PLWH (36 cases with type I adjudicated MI and 69 controls without MI) were selected from the Center for AIDS Research Network of Integrated Clinical Systems, a multicenter clinic‐based cohort. Controls were matched by demographics, CD4 cell count, and duration of viral suppression. In the SCOPE cohort, higher carnitine levels had a significant association with presence of carotid plaque and greater baseline and progression of mean carotid artery intima‐media thickness after adjusting for traditional cardiovascular disease risk factors. In the treated and suppressed subgroup, these associations with carnitine remained significant after adjustment for cardiovascular disease risk factors. In the Center for AIDS Research Network of Integrated Clinical Systems cohort, the risk of MI was significantly increased in subjects with carnitine levels in the highest quartile after adjustment for cardiovascular disease risk factors.

Conclusions

In PLWH, including the treated and suppressed subgroup, carnitine is independently associated with carotid artery intima‐media thickness, carotid plaque, and MI in 2 separate cohorts. These results emphasize the potential role of gut microbiota in HIV‐associated atherosclerosis and MI, especially in relation to carnitine metabolism.

Analysis of the Thiocapsa pfennigii polyhydroxyalkanoate synthase: subcloning, molecular characterization and generation of hybrid synthases with the corresponding Chromatium vinosum enzyme

The PHA synthase structural gene of Thiocapsa pfennigii was identified and subcloned on a 2.8-kbp BamHI restriction fragment, which was cloned recently from a genomic 15.6-kbp EcoRI restriction fragment. Nucleotide sequence analysis of this fragment revealed three open reading frames (ORFs), representing coding regions. Two ORFs encoded for the PhaE (Mr 40,950) and PhaC (Mr 40,190) subunits of the PHA synthase from T. pfennigii and exhibited high homology with the corresponding proteins of the Chromatium vinosum (52.8% and 85.2% amino acid identity) and the Thiocystis violacea (52.5% and 82.4%) PHA synthases, respectively. This confirmed that the T. pfennigii PHA synthase was composed of two different subunits. Also, with respect to the molecular organization of phaE and phaC, this region of the T. pfennigii genome resembled very much the corresponding regions of C. vinosum and of Thiocystis violacea. A recombinant strain of Pseudomonas putida, which overexpressed phaE and phaC from T. pfennigii, was used to isolate the PHA synthase by a two-step procedure including chromatography on Procion Blue H-ERD and hydroxyapatite. The isolated PHA synthase consisted of two proteins exhibiting the molecular weights predicted for PhaE and PhaC. Hybrid PHA synthases composed of PhaE from T. pfennigii and PhaC from C. vinosum and vice versa were constructed and functionally expressed in a PHA-negative mutant of P. putida; and the resulting PHAs were analyzed.