Transcript Cryptococcal IRIS in Africa: clinical

Cryptococcal IRIS in Africa: clinical
manifestations and pathogenesis
Paul R. Bohjanen, M.D., Ph.D.
Associate Professor of Microbiology and Medicine
University of Minnesota
Minneapolis, MN, USA
Professor in Residence
Infectious Diseases Institute
Makerere University
Kampala, Uganda
Outline:
1. Role of immune activation in HIV pathogenesis.
2. Use of microarrays to assess immune activation in HIVinfected Ugandan patients before and after initiation of
antiretroviral therapy.
3. Outcomes of cryptococcal meningitis in Uganda in the
era of antiretroviral therapy (ART).
4. Clinical features of HIV Immune Reconstitution
Inflammatory Syndrome (IRIS) in patients with recent
cryptococcal meningitis after initiation of ART.
5. Use of microarrays to assess biomarkers of IRIS after
initiation of ART in patients with or without recent
cryptococcal meningitis.
Primary HIV Infection
Viral Dissemination
Partial Immune Containment
Chronic Immune Activation
Destruction of Lymphoid Tissue
Decreased Circulating CD4 T Cells
AIDS
Immune Reconstitution
• Potent ARV therapy blocks viral replication and prevents
the destruction of CD4 T cells.
• This shifts the balance toward CD4 T cell regeneration and
improvement in immune function.
• CD4 T cell counts increase.
• Antigen-specific immune responses are restored.
Immune Reconstitution
• The bottom line is that patients who respond
to ART have improved immune function and
are at lower risk for the development of
opportunistic infections.
Is immune reconstitution always
beneficial?
Immune Reconstitution Inflammatory
Syndromes (IRIS):
• Immune Reconstitution Paradox: Recovery in the
function of the immune system with ART can
promote an inflammatory reaction to antigens that
were previously not recognized by the immune
system.
• This inflammatory reaction can sometimes lead to
worsening of a current or latent opportunistic
infection.
• The onset of IRIS often occurs 2-8 weeks after
initiation of ARV therapy but can occur earlier or
later.
IRIS: Triggering Antigens
• In IRIS, the flaring of specific immune responses to
microbial antigens occurs in the setting of improving
immunity after the initiation of effective ART.
• IRIS may represent either an appropriate inflammatory
response that was previously masked by severe immune
deficiency or a pathological exaggerated inflammatory
reaction.
• Inciting antigens may be from an active infection
(replicating microorganisms) or from the remnants of a
treated infection (microbial debris) or latent infection.
• IRIS is also associated with autoimmune disorders or
malignancies such as Kaposi’s sarcoma and lymphoma.
Pathogens associated with IRIS
Mycobacterium avium
Mycobacterium tuberculosis
Mycobacterium leprae
Cryptococcus neoformans
Pneumocystis jiroveci
Histoplasma capsulatum
Hepatitis B virus
Hepatitis C virus
Varicella-zoster virus
Cytomegalovirus
BK Virus
Parvovirus B19
JC virus
Papilloma virus
HHV-8 (KS)
Clinical Presentation
• IRIS can occur as early as a few days after starting ARV
therapy. In patients with baseline CD4+ T-cell counts below
50 cells/mm3, most events will happen within the first 8
weeks of therapy. Late IRIS with symptom onset after more
than 1 year of ARVs have been described.
• Patients typically become ill in the setting of improving
virologic and immunological measures.
• IRIS may be mistaken for a new opportunistic infection, but
it can sometimes be distinguished by an atypical
manifestation, such as localized inflammation where one
would expect disseminated disease.
• IRIS may also present as paradoxical worsening of a known
opportunistic infection.
• Depending on the site and activity of the immunologic
response, the severity of clinical symptoms can vary widely
from mild to life-threatening events.
IRIS Case Definition
• Evidence of clinical response to ART with:
– On ART
– >1 log10 copies/mL decrease in HIV RNA (if available)
• Infectious or Inflammatory condition within 6 months of ART
initiation
• Symptoms can not be explained by either:
– Newly acquired infection
– Expected clinical course of a previously recognized and
successfully treated infectious agent
– Treatment failure
– Side effects of ART.
– Complete ART non-compliance
IRIS Associated with Crytococcal
Meningitis
• IRIS may be associated with cryptococcal
meningitis following initiation of ART.
• Upon initiation of ART, ≈25% of CM patients
experience IRIS with increases in headache,
intracranial pressure, signs of inflammation,
and in ≈25%, serious complications include
loss of vision, cranial nerve palsies, reduced
cognition and death.
IRIS Management
• Evidence-based treatment recommendations are
lacking.
• Identify the inciting pathogen and treat it.
• Most cases of IRIS are managed without stopping
ARVs.
• In severe cases, treatment options include
stopping ARVs, steroids, NSAIDS, and surgical
treatment (for example drainage of abscesses).
Why is so much IRIS seen in Africa?
• IRIS occurs most often in patients with advanced HIV disease
and severe immunosuppression. Because of limited
availability of ART in Africa, treatment is often reserved only
for patients with advanced disease.
• Opportunistic infections associated with IRIS, such as
tuberculosis and cryptococcal meningitis, occur frequently in
Africa.
• Limited diagnostic capabilities in resource poor regions may
impair the diagnosis of alternative etiologies, such as a
second opportunistic infection. The diagnosis of IRIS is often
invoked when no other definitive diagnosis is found.
Research Questions
• What is the incidence of IRIS?
• How often is IRIS associated with significant
morbidity and mortality?
• Who is at greatest risk?
• How should IRIS be treated?
• Can the immune system be modulated to prevent
IRIS?
• In patients with IRIS-associated infections, such as
TB or CM, is it better to treat the OI first and then
start ART?
IRIS Study Design
Development of two pilot cohorts:
24 patients in each
Timing of IRIS after ART
Incidence Rate: 35%
Response to ART in Cohort 1 (24 patients):
Baseline:
CD4: 58 ± 60 cells/uL
viral load: 5.5 ± 5.4 log
At 3 months:
CD4: 192 ±133 cells (P < .001) with 23 of 24 individuals having
a >50 CD4 cell/uL increase.
viral load: undetectable among 19 of 24 patients (Range of
five detectable subjects: 431-1,657 HIV RNA copies/mL).
20 of 24 patients have been followed for > 6 months with 8
study visits, and 100% follow up has occurred.
IRIS Events (Cohort 1)
RNA
done
Study ID
Event
Timing (weeks)
X
01
HSV
4
X
01
VZV zoster
29
X
13
HSV
4
X
14
HPV - New genital warts
24
X
17
Tongue Cryptococcoma
20
024
VZV
22
028
Prurigo event
18
A patient without prior cryptococcal disease and negative serum
CRAG at enrollment, developed progressive tongue swelling. Biopsy
revealed encapsulated yeast consistent with a cryptococcoma which
regressed with two weeks of fluconazole therapy.
Cryptococcal Meningitis Outcomes
Suspected
Meningitis
N=71
Non-CM meningitis
N=22
Cryptococcal Meningitis
N=49
On ART, IRIS
Event
N=5
Survived
Hospitalization
N=36
Died during
hospitalization
N=8
Lost prior to
ART
N=5
Died prior to
ART
N=7
Started ART
N=24
37%
Alive at 6
months
N=18
Died after ART
start
N=6
Response to ART in Cohort 2 (24 patients):
Baseline:
CD4: 29 ± 27 cells/uL
viral load: 350,000 ± 258,000 copies/mL
At 3 months:
CD4: 80 ± 63 cells
viral load: 846 ± 1340 copies/mL
IRIS Events in Cohort 2
ID
IRIS Event
Timing
(weeks)
X
1018
Meningitis Relapse
Aseptic Meningitis – mania, India Ink Pos, Cx
neg.
12
20
X
1020
Pulmonary TB unmasking
32
1029
CNS Cryptococcoma v. Toxoplasmosis
14
1029
VZV
19
X
1030
Generalized lymphadenopathy; Died
6
X
1032
RLL Pneumonitis
12
X
1046
Blurred vision; CMV Retinitis. Died @ 13wk
4
1058
Aseptic Meningitis, Died
18
X
1059
Bilateral Blindness
20
X
1065
Aseptic meningitis
2
1073
Bronchopneumonia, pneumonitis. Died
6.5
Six patients have died since enrollment.
Immune activation in peripheral blood
of HIV-infected patients in Uganda
before and after initiation of ART
Most of the transcripts that were down-regulated
after ART are T cell activation genes.
Multiple components of TNF and Interferon response
pathways were down-regulated following initiation of ART
Immune activation in peripheral blood
of HIV-infected patients in Uganda
who do or do not develop IRIS after
initiation of ART
Expression patterns of hundreds of genes
are altered in patients with CM
Baseline Gene Expression that Predicts IRIS
P=0.005
Gene Expression Predictors of IRIS
(Aim 1)
• Cell Signaling Pathways
– Chemokine Signaling
– PI3Kinase/AKT Signaling
• Cell Death Pathways
• Glycolysis/Gluconeogenesis Pathways
• Drug Metabolism Pathways
– PGK1; metabolism of lamivudine
Gene Expression Predictors of CM IRIS
(Aim 2)
• Cell Signaling Pathways
– NF-B Signaling
– Toll-like Receptor Signaling
– Death Receptor Signaling
• Cell Death Pathways
• Cell Cycle Pathways
• Transcription Factors
Biomarkers (signatures)
of IRIS
and CM IRIS
Biomarkers (signatures) of IRIS
Biomarkers (signatures) of CM and CM IRIS
*
*
No OI Controls
CM IRIS
**
CM Controls
* IRIS, non-CM events
** TB at 6½ months
Gene Expression Associated with CM IRIS
Conclusions
1. HIV IRIS occurs frequently in sub-Saharan Africa, appearing in
more than 1/3 of the patients in our study.
2. IRIS has a diverse spectrum of clinical presentations and a
wide range of severity.
3. Mortality is high among patients with CM both prior to initiation
of ART and after ART is initiated.
4. IRIS occurs frequently in patients with CM with manifestations
related to CM as well as other OIs that may be present.
5. The normal response to ART is characterized by a decrease in
immune activation that can be measured in peripheral blood
using microarrays.
6. Immune activation in IRIS can be measured in peripheral blood
using microarrays and specific biomarkers or patterns of
biomarkers (signatures) may be useful to diagnose IRIS.
7. Even prior to initiation of ART, the expression of biomarkers in
peripheral blood may be useful for predicting patients’ risk for
subsequent development of IRIS.
Research Trainees
Fellows:
David Meya MBChB (ID-IDI)
David Boulware, MD (ID-U of MN)
Irina Vlasova MD,PhD (Postdoc- U of MN)
Students:
Joshua Rhein (4th year Med)
Sam Goblirsch (4th year Med)
Jack Staddon (Combined MD/PhD)
Darlisha Williams (MPH student)
Sarah Lee (Combined MD/MPH)
Residents:
Brett Handel-Paterson, MD (Med-Peds)
Erin Huiras, MD (Dermatology)
Faculty Collaborators
IDI/Makerere Univ:
Andrew Kambugu (co-PI)
Keith McAdam
Harriet Mayanja-Kizza
Moses Kamya
Univ of Manitoba:
Allan Ronald
Univ of CO:
Edward Janoff (co-PI)
Univ of WA:
Merle Sande
Univ of MN:
Paul Bohjanen (co-PI)
Tim Behrens
Phil Peterson
James Neaton
Tracy Bergemann
Institute of Tropical
Medicine, Antwerp:
Bob Colebunders
Luc Kestens
Duke Univ:
John Perfect