T cells isolated from both cured and asymptomatic PBMC activate autologous macrophages to kill intracellular amastigotes. IFN-γ activates macrophages to kill intracellular parasites so its role in VL has been studied extensively and IFN-γ production is often used as a marker of protective immunity. Cured PBMC generally secrete less IFN-γ and more interleukin 10 (IL-10) in response to Leishmania antigens than asymptomatic PBMC. IL-12 is important in the development and maintenance of Type 1 T helper cell responses and protective immunity so its role in VL has also been studied. Addition of IL-12 to some VL PBMC increases proliferation and IFN-γ secretion in response to Leishmania antigens and anti-IL-12 inhibits proliferation and IFN-γ secretion by some cured PBMC. Other cytokines also appear to be important in immunity to Leishmania but their roles are not as well characterized.Leishmania antigen stimulation of PBMC from cured patients show a mixed T helper cell and regulatory T cell response. Both CD4+ and CD8+ T cells contributed to IFN-γ production. Studies of Leishmania antigen specific T cell clones from cured patient PBMC confirm that cured patients have a mixed T cell response that involves both CD4+ helper T cells and CD4+ and CD8+ regulatory T cells. Two studies of asymptomatic T cell clones show that most have Type 1 profiles and secrete more IFN-γ than T cell clones from cured patients. Neither study revealed the presence of Type 2 or regulatory T cells.
Generally, the symptoms of NPD also impair the persons psychological abilities to function socially, either at work or at school, or within important societal settings. The DSM-5 indicates that, in order to qualify as symptomatic of NPD, the persons manifested personality traits must substantially differ from social norms. ICD-11 and ICD-10
In the International Statistical Classification of Diseases and Related Health Problems, 11th Edition ICD-11 of the World Health Organization (WHO), all personality disorders are diagnosed under a single title called "personality disorder". The criteria for diagnosis are mainly concerned with assessing dysfunction, distress and maladaptive behavior as opposed to attributing specific personality traits. In the previous edition, the ICD-10, narcissistic personality disorder (NPD) is listed under the category of "other specific personality disorders". This means similarly to the ICD-11, the ICD-10 required that cases otherwise described as NPD in the DSM-5 would only need to meet a general set of diagnostic criteria. Associated features
People with NPD exaggerate their skills, accomplishments, and their degree of intimacy with people they consider high-status. A sense of personal superiority may lead them to monopolize conversations, look down on others or to become impatient and disdainful when other persons talk about themselves. This behavior correlates to an overall worse functioning in areas of life like work and intimate romantic relationships.People with NPD have been observed to use psychosocial strategies, such as the tendency to devalue and derogate and to insult and blame other people, usually with anger and hostility towards peoples responses to their anti-social behavior.