Does Monocyte Chemoattractant Protein-1 Levels determine the prognosis of COVID-19 disease in kidney transplant recipients?

Background

In the normal population, a high MCP-1 level is an important biomarker for the progression of COVID-19 disease. This study aimed to investigate whether MCP-1 level can determine the disease prognosis in kidney transplant (KT) patients with COVID-19.

Methods

A total of 89 patients, including 49 KT patients (Group 1) diagnosed with COVID-19 who required hospitalization, and 40 KT patients who did not have COVID-19 disease (Group 2), were included. Demographic characteristics and laboratory results of the patients were recorded. The serum reserved for MCP-1 was stored at -80 degrees and studied blindly by a single microbiologist at the end of the study.

Results

While the mean age of the patients was 51.0 (40.0-59.50) years in Group 1, it was 48.0 (40.75-54.75) years in Group 2(P>0.05). In terms of the female gender, it was 36 (73.5%) and 27 (67.5%) in Group 1 and Group 2, respectively (P>0.05). Similarly, there was no significant difference between the two groups regarding primary disease and basal graft function (p>0.05). There was a statistically significant difference in inflammation indicators in Group 1 compared to Group 2(P<0.05). A correlation was found between inflammation indicators and COVID-19(P<0.05). However, no significant correlation was detected between COVID-19 disease and MCP-1 levels in both groups (P>0.05). Also, according to basal MCP-1 levels, we did not find a significant difference between survival and non-survival patients (164,0pg/mL (146,0-202,0) vs 156,0 pg/mL (143,0-173,0), respectively  (p>0.05).

Conclusion

MCP-1, an indicator of inflammation, was not found to be a predictor of prognosis of COVID-19 disease in kidney recipients.

In utero infection with porcine reproductive and respiratory syndrome virus modulates leukocyte subpopulations in peripheral blood and bronchoalveolar fluid of surviving piglets

It is well known that piglets congenitally infected with porcine reproductive and respiratory syndrome virus (PRRSV) can be viremic at birth, and that preweaning mortality due to secondary infections often increases during acute outbreaks of PRRS. Therefore, an immunosuppressive effect of in utero infection has been suggested. The aim of the present study was to characterise the changes of leukocyte populations in piglets surviving in utero infection with PRRSV. A total of 27 liveborn uninfected control piglets and 22 piglets infected transplacentally with a Danish strain of PRRSV were included. At 2 and 4 weeks of age, 21 of 22 (96%) and 7 of 14 (50%) examined infected piglets were still viremic, whereas PRRSV could not be detected in the six infected piglets examined at 6 weeks of age. Flow cytometry analysis was used to determine the phenotypic composition of leukocytes in peripheral blood and bronchoalveolar lavage fluid (BALF) of 2-, 4- and 6-week-old infected piglets and age-matched uninfected controls. The key observation in the present study is that high levels of CD8(+) cells constitute a dominant feature in peripheral blood and BALF of piglets surviving in utero infection with PRRSV. In BALF, the average high level of CD8(+) cells in 2-week-old infected piglets (33.4 +/- 12.6%) was followed by a decline to 7.3 +/- 3.0 and 11.1 +/- 3.0% at 4 and 6 weeks of age. BALF of control piglets contained 1.6 +/- 0.9, 2.3 +/- 1.8 and 1.9 +/- 0.5% CD8(+) cells, only. In peripheral blood, however, the average number of CD8(+) cells remained at high levels in the infected piglets throughout the post-natal experimental period (2.8 +/- 1.9, 2.9 +/- 1.8 and 3.2 +/- 1.7 x 10(6) CD8(+) cells/ml at 2, 4 and 6 weeks, respectively). In the controls, the average levels of CD8(+) cells were 0.9+/-0.2, 1.9 +/- 1.7 and 1.6 +/- 0.5 x 10(6)/ml, respectively. Furthermore, the numbers of CD2(+) , CD4(+)CD8(+) and SLA-classII(+) cells, respectively, in peripheral blood, together with the levels of CD2(+) and CD3(+) cells in BALF were increased in the infected piglets infected in utero compared to the uninfected controls. The kinetic analyses carried out in the present study reflect that in utero infection with PRRSV modulates immune cell populations in peripheral blood and BALF of surviving piglets. The observed changes are characterised by high levels of CD8(+) cells supporting an important role of these cells in PRRSV infection. The present results, however, do not support the existence of post-natal immunosuppression following in utero infection with PRRSV.

Immune responses in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV)

In three successive experiments, the immune functions of pigs persistently infected with the porcine reproductive and respiratory syndrome virus (PRRSV) have been evaluated. Non-specific immune responses were analyzed over a period of 12 weeks post-infection (PI). In addition, the capacity of PRRSV-infected pigs to develop an efficient immune response against pseudorabies virus (PRV) glycoproteins and to resist to a subsequent virulent challenge was investigated. Our results demonstrate that PRRSV produced minor effects on the immune system of pigs. The skin delayed type hypersensitivity (DTH) in response to phytohemagglutinine injection was slightly diminished one week after challenge, but was restored thereafter. However, three weeks after the infection, the total white blood cell count, and the number of CD2+, CD8+ and IgM+ cells were enhanced. The increase in numbers of CD8+ cells persisted for three consecutive weeks. Serum immunoglobulins in infected pigs also increased by week 3 PI and up to 8 weeks PI. These results show that PRRSV may have stimulating effects on the pig immune system during the phase of long-lasting infection. After immunization with PRV glycoproteins, the production of anti-PRV antibodies and skin DTH response against PRV glycoproteins were not affected. On the contrary, following a virulent PRV challenge, PRRSV-infected pigs developed a better secondary antibody response and their resistance to the infection was as effective as in control pigs. Taken together, our data do not support a systemic immunosuppressive effect of PRRSV, during the persistent phase of infection. Other mechanisms may therefore apply to explain the emergence of secondary infections in endemically infected herds.