Biology Reference
In-Depth Information
in falciparum-associated AKI, or acute cortical necrosis, as reported in one
series (
Kute et al., 2012b
), requires further study.
With the increasing reports of thrombotic microangiopathy in vivax-
associated AKI (
Sinha et al., 2012
;
Saharan et al., 2008
;
Sharma et al., 1993
),
the extent to which thrombotic microangiopathy underlies vivax-associ-
ated AKI also requires further prospective studies. Elevated VWF and low
levels of the VWF-cleaving protein ADAMTS-13 are known to occur in
vivax malaria (
de Mast et al., 2009
) and are linked to disease severity in fal-
ciparum malaria (
Larkin et al., 2009
); these processes may underlie throm-
botic microangiopathy in these patients. Autopsy studies will also be useful.
Although six of the 17 fatal Manaus autopsy cases had AKI (as part of mul-
tiorgan dysfunction), renal histopathology was not included in the initial
histopathology report from this series (
Lacerda et al., 2012
).
11.2.4. Coma
The aetiology of the coma associated with
P. vivax
is not known and the
role of co-infections remains unclear (see
Lampah et al., 2011
;
Anstey
et al., 2009
for review). One case of coma associated with microscopy-
diagnosed
P. vivax-P. falciparum
mixed infection reported accumulation of '
P.
vivax
-infected' red cells within retinal and choroidal blood vessels (
Biswas
et al., 1996
), however, these are likely to have been
P. falciparum
. The rarity
of coma in
P. vivax
relative to
P. falciparum
and its absence in
Plasmodium
knowlesi
(
William et al., 2011
;
Daneshvar et al., 2009
) make it unlikely that
the cerebrovascular sequestration of parasitized red cells characteristic of
P.
falciparum
occurs to a significant degree with these other parasites. This con-
tention is supported by the absence of
P. vivax
DNA, albeit post-treatment,
in both the single Brazilian autopsy case of coma attributed to
P. vivax
(
Lacerda et al., 2012
) and the post-mortem brain aspirates from three PNG
children with coma associated with mixed
P. falciparum
-
P. vivax
infection
(
Manning et al., 2012
).
While coma has been described in one of nine patients with throm-
botic microangiopathy-associated AKI (
Sinha et al., 2012
), none of the
cases of PCR-confirmed vivax-associated coma in Papua had renal impair-
ment, or significant anaemia or thrombocytopenia to suggest a systemic
thrombotic microangiopathy in these patients (
Lampah et al., 2011
). Nev-
ertheless, prospective evaluation of these parameters in other series of vivax-
associated coma, as well as schistocytes, plasma concentrations of VWF
and ADAMTS-13, are needed to investigate the potential contribution of
thrombotic microangiopathy in vivax-associated coma.
