A unified pathogenesis for kidney diseases, including genetic diseases and cancers, by the protein-homeostasis-system hypothesis

Common immunopathogenesis of central nervous system diseases: the protein-homeostasis-system hypothesis

There are hundreds of central nervous system (CNS) diseases, but there are few diseases for which the etiology or pathogenesis is understood as well as those of other organ-specific diseases. Cells in the CNS are selectively protected from external and internal insults by the blood–brain barrier. Thus, the neuroimmune system, including microglia and immune proteins, might control external or internal insults that the adaptive immune system cannot control or mitigate. The pathologic findings differ by disease and show a state of inflammation that reflects the relationship between etiological or inflammation-inducing substances and corresponding immune reactions. Current immunological concepts about infectious diseases and infection-associated immune-mediated diseases, including those in the CNS, can only partly explain the pathophysiology of disease because they are based on the idea that host cell injury is caused by pathogens. Because every disease involves etiological or triggering substances for disease-onset, the protein-homeostasis-system (PHS) hypothesis proposes that the immune systems in the host control those substances according to the size and biochemical properties of the substances. In this article, I propose a common immunopathogenesis of CNS diseases, including prion diseases, Alzheimer’s disease, and genetic diseases, through the PHS hypothesis.

Etiological and pathophysiological enigmas of severe coronavirus disease 2019, multisystem inflammatory syndrome in children, and Kawasaki disease

During the coronavirus disease 2019 (COVID-19) pandemic, a novel multisystem inflammatory syndrome in children (MIS-C) has been reported worldwide since the first cases were reported in Europe in April 2020. MIS-C is temporally associated with severe acute respiratory syndrome coronavirus 2 infection and shows Kawasaki disease (KD)-like features. The epidemiological and clinical characteristics in COVID-19, KD, and MIS-C differ, but severe cases of each disease share similar clinical and laboratory findings such as a protracted clinical course, multiorgan involvement, and similar activated biomarkers. These findings suggest that a common control system of the host may act against severe disease insult. To solve the enigmas, we proposed the protein-homeostasis-system hypothesis in that every disease involves etiological substances and the host's immune system controls them by their size and biochemical properties. Also, it is proposed that the etiological agents of KD and MIS-C might be certain strains in the microbiota of human species and etiological substances in severe COVID-19, KD, and MIS-C originate from pathogen-infected cells. Since disease severity depends on the amounts of inflammation-inducing substances and corresponding immune activation in the early stage of the disease, an early proper dose of corticosteroids and/or intravenous immunoglobulin (IVIG) may help reduce morbidity and possibly mortality among patients with these diseases. Corticosteroids are low cost and an analogue of host-origin cortisol among immune modulators. This study's findings will help clinicians treating severe COVID-19, KD, and MIS-C, especially in developing countries, where IVIG and biologics supplies are insufficient.

“Machine-Dependent”: The Lived Experiences of Patients Receiving Hemodialysis in Pakistan

This study aimed to explore the lived experiences of patients receiving maintenance hemodialysis in Pakistan. Purposive sampling was used to recruit 24 patients and six healthcare professionals, each participated in a semi-structured interview. Interpretive Phenomenological Analysis was used to analyze interviews’ data. Two superordinate themes, “The experience of hemodialysis” and “The conceptualizations of hemodialysis” as well as six sub-themes were identified. The experience of hemodialysis was related to, the implications of HD procedure on everyday life, social, cognitive, emotional, financial, and occupational influences. While all participants recognized the importance of hemodialysis for their survival, their conceptualizations of the treatment varied. Despite facing multiple challenges, optimism and independence were observed among participants. Stigma related to hemodialysis, and role adaptation, which appear unique to the Pakistani context, highlight a need for tailored interventions designed to enhance and maintain the mental health of patients receiving hemodialysis in Pakistan.

The solution on enigmas in COVID-19: the protein-homeostasis-system hypothesis

Infectious diseases, including coronavirus disease 2019 (COVID-19), are representative, of which etiology is known in all human diseases. However, many enigmas persist in relation to COVID-19, including different clinical phenotypes and incubation periods across individuals, species-specificity, appearance of cytokine storm and lymphopenia, and the mechanism of damage to organ cells. Current immunological concepts have limitations to explain these unsolved issues. Meanwhile, results of clinical, pathological, and animal studies have suggested that the virus itself is not a direct cause of acute injury to the lung or other organ cells. For better understanding of COVID-19, a presumed immunopathogenesis of COVID-19 is presented under the protein-homeostasis-system hypothesis; every disease, including COVID-19, has associated etiological substances, and the host immune system controls these diverse substances according to the size and biochemical property. These etiological substances, inducing inflammation and subsequent tissue injury, are smaller substances derived from virus-infected cells. Initially acting nonspecific adaptive immune reaction with cytokine imbalance may be responsible for target cell injury. Furthermore, substances from initial target cell injury and secondary bacterial invasion can induce further inflammation if released from local or systemic circulation. COVID-19 patients with pneumonia show hypercytokinemia with lymphocytopenia corresponding to the severity of pneumonia at early stages. Thus, early immune-modulator treatment, including corticosteroids and intravenous immunoglobulin, has an immunological rationale. It could help reduce the morbidity and possibly mortality of older patients with underlying conditions.

Immunopathogenesis of COVID-19 and early immunomodulators

The novel coronavirus disease 2019 (COVID-19) is spreading globally. Although its etiologic agent is discovered as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), there are many unsolved issues in COVID-19 and other infectious diseases. The causes of different clinical phenotypes and incubation periods among individuals, species specificity, and cytokine storm with lymphopenia as well as the mechanism of damage to organ cells are unknown. It has been suggested that in viral pneumonia, virus itself is not a direct cause of acute lung injury; rather, aberrant immune reactions of the host to the insults from viral infection are responsible. According to its epidemiological and clinical characteristics, SARS-CoV-2 may be a virus with low virulence in nature that has adapted to the human species. Current immunological concepts have limited ability to explain such unsolved issues, and a presumed immunopathogenesis of COVID-19 is presented under the proteinhomeostasis-system hypothesis. Every disease, including COVID-19, has etiological substances controlled by the host immune system according to size and biochemical properties. Patients with severe pneumonia caused by SARS-CoV-2 show more severe hypercytokinemia with corresponding lymphocytopenia than patients with mild pneumonia; thus, early immunomodulator treatment, including corticosteroids, has been considered. However, current guidelines recommend their use only for patients with advanced pneumonia or acute respiratory distress syndrome. Since the immunopathogenesis of pneumonia may be the same for all patients regardless of age or severity and the critical immune-mediated lung injury may begin in the early stage of the disease, early immunomodulator treatment, including corticosteroids and intravenous immunoglobulin, can help reduce morbidity and possibly mortality rates of older patients with underlying conditions.

Kawasaki Disease Following Severe Sunburn Injury

Background: Although an etiology of Kawasaki disease (KD) is unknown, an aberrant innate immune system in predisposed individuals has been proposed to play a key role in the development of KD vasculitis. Various etiological pathogens have been proposed as the trigger of KD and a scaled injury preceding symptom onset has been reported as one of them. Here, we report a 17-month-old Japanese female who was hospitalized due to high fever lasting for 4 days with infection ruled out as a cause. On admission, she displayed severe sunburn all over her body following a prolonged period of outdoor play 5 days ago. On the 5 day of illness, she developed complete KD. Serum levels of high mobility group box 1, a representative for damage-associated molecular patterns (DAMPs), were elevated during acute phase and continued to decrease during subacute phase. This unique course suggested the inflammatory process of KD involving innate immunity via DAMPs.

White Blood Cell and Neutrophil Counts and Response to Intravenous Immunoglobulin in Kawasaki Disease

We explored parameters to predicting the efficacy of intravenous immunoglobulin (IVIG) therapy for patients with Kawasaki disease (KD). We retrospectively analyzed the laboratory data of 77 children with KD treated with IVIG. Data obtained before and within 24 hours after IVIG therapy were compared between responders and nonresponders. The white blood cell (WBC) and neutrophil counts were significantly lower in responders than nonresponders within 24 hours after IVIG. The areas under the receiver operating characteristics curves of the WBC and neutrophil counts were 0.846 and 0.754, respectively. The WBC and neutrophil counts differed significantly between responders and nonresponders (the latter developed recurrent pyrexia after transient fever resolution). In conclusion, WBC and neutrophil counts within 24 hours after IVIG usefully predict the efficacy of IVIG therapy for those with KD, and identify nonresponders to such therapy.

Alterations in Lipid Profile of the Aging Kidney Identified by MALDI Imaging Mass Spectrometry

During aging, the kidney undergoes functional and physiological changes that are closely affiliated with chronic kidney disease (CKD). There is increasing evidence supporting the role of lipid or lipid-derived mediators in the pathogenesis of CKD and other aging-related diseases. To understand the role of lipids in various metabolic processes during kidney aging, we conducted matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) analysis in kidneys harvested from young (2 months old, n = 3) and old mice (24 months old, n = 3). MALDI-IMS analysis showed an increase in ceramide level and a decrease in sphingomyelin (SM) and phosphatidylcholine (PC) levels in kidneys of old mice. The increased expression of cPLA2 and SMPD1 protein in aged kidney was confirmed by immunohistochemistry and Western blot analysis. Our MALDI-IMS data showed the altered distribution of lipids in aged kidney as indicative of aging-related functional changes of the kidney. Combined analysis of MALDI-IMS and IHC confirmed lipidomic changes and expression levels of responsible enzymes as well as morphological changes.

A Presumed Etiology of Kawasaki Disease Based on Epidemiological Comparison With Infectious or Immune-Mediated Diseases

Background: Kawasaki disease (KD) may be associated with infection of unknown pathogen(s). For predicting of the etiology of KD, we evaluated epidemiological characteristics in KD, common infectious diseases and immune-mediated diseases in childhood. Methods: We respectively, reviewed the data of patients with KD, influenza, aseptic meningitis, exanthem subitum (ES), Mycoplasma pneumoniae (MP) pneumonia, acute pyelonephritis (APN), Henoch-Schönlein purpura (HSP), acute poststreptococcal glomerulonephritis (APSGN), and childhood asthma. We compared and interpreted epidemiological data across the groups. Results: In age distribution, KD, APN, and ES showed a similar pattern in that majority of patients were infants or young children, and other diseases showed a relatively even age-distribution which had a peak age, mainly 5-6 years, with bell-shape patterns. In annual-case pattern, there were epidemic years in aseptic meningitis and MP pneumonia, and the fluctuated annual cases were seen in other diseases. The trends of decreasing cases were seen in APSGN, HSP, and childhood asthma in recent years. In seasonal frequency, influenza or aseptic meningitis occurred in mainly winter or summer season, respectively. HSP and APSGN cases had less in summer, and KD, APN, and ES showed relatively even occurrence throughout a year without significant seasonal variations. Conclusions: Our results suggest that KD agents may be associated with normal flora that are influenced by environmental changes, since pathogens of APN and ES could be regarded as normal flora that originate from the host itself or ubiquitously existing human reservoirs.

Dialysis: A Review of the Mechanisms Underlying Complications in the Management of Chronic Renal Failure

Chronic renal failure (CRF) is the most prevalent, worldwide public health problem of the elderly population. The main cause of CRF is a damaged kidney. There are five stages of CRF based on the glomerular filtration rate (GFR), and stage 5 (GFR < 15 ml/min/1.73m²) is often called an end-stage renal disease (ESRD). In CRF, there is an accumulation of toxins and excess water due to compromised renal function. Dialysis is the preferred way to treat ESRD and remove accumulated toxins from the body. The cardiovascular risk associated with dialysis is 10 to 20 times higher in patients undergoing dialysis than in normal people. The inflamed kidneys and the process of dialysis also affect endothelial function, aggravating the risk of hypertension and cardiac problems. Therefore, both physicians and patients should be aware of the consequences of undergoing dialysis. There is an urgent need to educate CRF patients regarding facts about the disease, medications, dietary habits, and various measures required to manage the condition and lead a normal life. This paper attempts to delineate the mechanisms that could result in cardiovascular and other complications among CRF patients undergoing dialysis.