People can get Type 2 as a child and T1 as an octogenarian. However we don't all fit in 2 little boxes
The fact that you had DKA at diagnosis suggests that you had very high glucose levels and a relative lack of insulin, hence the DKA .
If you don't have autoimmune markers then you probably don't have autoimmune T1. Nevertheless, if you look at any studies, even of childhood onset T1, there is always a proportion of people who seem to have T1 but don't have autoimmune antibodies. This might mean that the antibodies haven't been detected or that there aren't any.
The World Health organisation categorisation actually has a category for this Type 1b this is idiopathic T1 ie T1 of no known origin. (Type 1a is autoimmune)
Just to demonstrate that definition/ diagnosis isn't always easy
(not saying that you have this; just showing that 2 boxes don't always cover it!)
There is at least one form of diabetes which is not auto immune . It is ketosis prone and needs insulin at diagnosis. It goes under a variety of labels (Type1b, ketosis prone T2, Flatbush diabetes) . Where it differs from T1a (autoimmune T1) is that It may go into remission and can sometimes be treated by oral tablets or even diet alone . Unfortunately the remission is not always permanent and the person can develop DKA again. (and also go into remission again)
This form was first discovered in Americans with an African ancestry and people directly from N and W Africa have been found to have it. There are also American 'Hispanics' with it. However there are reports of people from other areas of the world who seem to have a similar form of diabetes.
Michael Barker, a blogger with ketosis prone diabetes lists some papers here (I haven't gone through them so don't know how valid it is)
http://www.tudiabetes.org/profiles/blog ... people-get
Academic paper about this form of diabetes:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2528854/
There are also other 'types'
Type 1.5 usually refers to LADA (latent autoimmune diabetes in adults) which is a form of Type 1 but the autoimmune destruction of beta cells is more gradual than 'classic' type 1.
Occasionally T1.5 refers to MODY (misnamed as Maturity onset diabetes of the young). This is a genetic form of diabetes and so 'runs' in families.
http://en.wikipedia.org/wiki/Maturity_o ... _the_young
A type 2 who has lost beta cell function is still a type 2 .