Oxyphil cells in primary hyperparathyroidism: a clinicopathological study

BACKGROUND

The role of oxyphil cells (OxC) in primary hyperparathyroidism (PHPT) still remains controversial. Historically, they were believed to be involuted cells. However, they could play an important role in hormone secretion. The clinical behavior of OxC-rich adenomas and preoperative PHPT localization tests have been widely studied. The aim of this study is to analyze the implications of OxC in PHTP.

METHODS

A retrospective cohort study of patients undergoing parathyroidectomy for PHPT was conducted. Additionally, we included normal glands removed in the context of PHPT or inadvertently during a thyroidectomy. All glands were reviewed independently by three researchers, performing a semi-quantitative analysis of the percentage of OxC. Groups with < 25% OxC and > 75% OxC were compared.

RESULTS

In the period 2010-2017, 238 patients and 261 removed glands were included (8.8% OxCA > 75%). There were no differences in symptomatology and levels of preoperative calcium, parathormone, or 25-OH vitamin. Patients with OxCA > 75% had worse preoperative glomerular filtration rate (81.2 vs. 69.7 mL/min/1.73 m²; p = 0.043). They also had a trend towards larger size and weight (17 vs. 20 mm, p = 0.135 and 562 vs. 875 mg, p = 0.495), while ultrasound was found to have better accuracy (48.3% vs. 73.7%; p = 0.035). There were no normal glands with a content of OxC > 75%.

CONCLUSIONS

Our study suggests that phosphocalcic metabolism is not influenced by the presence of a high content of OxC in the parathyroid glands. A high content of OxC seems to be exclusive to pathologic glands and could be related to the deterioration of renal function in patients with PHPT.

Integrated miRNA and mRNA expression profiling identifies novel targets and pathological mechanisms in autoimmune thyroid diseases

Background

The mechanisms underlying autoimmune thyroid disease (AITD) remain elusive. Identification of such mechanisms would reveal novel and/or better therapeutic targets. Here, we use integrated analysis of miRNAs and mRNAs expression profiling to identify potential therapeutic targets involved in the mechanisms underlying AITD.

Methods

miRNA and mRNA from twenty fresh-frozen thyroid tissues (15 from AITD patients and 5 from healthy controls) were subjected to next-generation sequencing. An anti-correlated method revealed potential pathways and disease targets, including proteins involved in the formation of primary cilia. Thus, we examined the distribution and length of primary cilia in thyroid tissues from AITD and controls using immunofluorescence and scanning electron microscopy, and parsed cilia formation in thyroid cell lines in response to inflammatory stimuli in the presence of miRNA mimics.

Findings

We found that the expression of miR-21-5p, miR-146b-3p, miR-5571-3p and miR-6503-3p was anti-correlated with Enolase 4 (ENO4), in-turned planar cell polarity protein (INTU), kinesin family member 27 (KIF27), parkin co-regulated (PACRG) and serine/threonine kinase 36 (STK36) genes. Functional classification of these miRNA/mRNAs revealed that their differential expression was associated with cilia organization. We demonstrated that the number and length of primary cilia in thyroid tissues was significantly lower in AITD than in control (frequency of follicular ciliated cells in controls = 67.54% vs a mean of 22.74% and 21.61% in HT and GD respectively p = 0.0001, by one-way ANOVA test). In addition, pro-inflammatory cytokines (IFNγ and TNFα) and specific miRNA mimics for the newly identified target genes affected cilia appearance in thyroid cell lines.

Interpretation

Integrated miRNA/gene expression analysis has identified abnormal ciliogenesis as a novel susceptibility pathway that is involved in the pathogenesis of AITD. These results reflect that ciliogenesis plays a relevant role in AITD, and opens research pathways to design therapeutic targets in AITD.

Funding

Instituto de Salud Carlos III, Comunidad de Madrid, Grupo Español de Tumores Neuroendocrinos y Endocrinos, Ministerio de Economía y Empresa and FEDER.