immunopharmacology Flashcards
calcineurin inhibitors
cyclosporin A
Tacrolimus (FK506),
(Pimecrolimus)
mTOR inhibitor
Sirolimus (rapamycin)
(everolimus
temsirolimus)
JAK kinase inhibitors
Tofacinitib
(Baricitinib
Ruxolitinib
Upadacitinib)
inhibitors of purin or pyrimidine synthesis
methotraxate
leflunomide
Azathioprine
Myclophenolate Mofetil
alkylating agents
cyclophoyphamide
BLOCKING T CELL SURFACE MOLECULES INVOLVED IN SIGNALING OF IMMUNOGLOBULINS
ANTITHYMOCYTE GLOBULIN (ATG)
Rho (D) immunoglobulin; Antilymphocyte globulins (ALG)
ANTIBODIES AGAINST T CELLS
not on the list
Basiliximab
Muromonab-CD3
ANTIBODIES AGAINST B CELLS
RITUXIMAB
ANTIBODIES AGAINST TNFa
INFLIXIMAB; ADALIMUMAB
ANTIBODIES AGAINST IL-1ß
NOT ON THE LIST
Canakinumab, Rilonacept
ANTIBODIES AGAINST Il-6R
TOCILIZUMAB
Sarilumab
ANTIBODIES AGAINST IL-17
not on the list
Secukinumab, Ixekizumab
ANTIBODIES AGAINST IL-12/23
USTEKINUMAB
ANTIBODIES AGAINST alpha4-integrin
NATALIZUMAB
ANTIBODIES AGAINST IL-13R and IL-4alpha-R
DUPILUMAB
CTLA 4/Fc fusionprotein
ABATACEPT (betalacept)
calcineurin function
Tcell receptor activation results in Ca+2 influx, activation of calcineurin by Ca+2 (phosphatase), dephosphorylation of NFAT results in its movement to the nucleus, in concert with other nuclear factors -> activation of genes encoding cytokines ( IL-2) r-> release -> cell mediated immune response
cyclosporin A
calcineurin inhibitor, blocks IL1+2
inhibits secondarily macrophage-T-cell-interaction, T-cell responsiveness, T-cell-dependen-B-cell function
forms a complex with cyclophylline
blocks cellular immunity ,
IV solvent can cause anaphylaxis, oral bioavailabilty is 20-50 % , grapefruit juice increases bioavailability by as much as 63%, CYP3A4
SE: nephrotoxicity, hepatotoxicity, hypertension, hyperglycemia, gingival hyperplasia, hirsutism, CNS disorders,stirelity, cardiotoxicity, neurotoxicity, neutropenia, (anemia), thrombocytopenia,
Bladder cancer is rare but must be looked for every 5 years
Indication: RA, (SLE, polymyositis, dermatomyositis, JCA, Behcet disease, Wegener granulomatosis)
isolated from polypocladium inflatum
Tacrolimus
Pimercrolimus
(isolated from Streptomyces tsubaensis).
It binds to FKBP 12 (FK Binding Protein,
macrophyllin) (peptidylprolyl) . The complex blocks calcineurin
more potent than cyclosporin A
Pimercrolimus is a local drug
Use: transplants, Auto-Immune-diseases, GVH, creme for atopic dermatitis + psoriasis
SE: no gingival hyperplasia, more psychological problems,
nephrotoxicity, hepatotoxicity, hypertension, hyperglycemia, neurotoxicity , hyperkalemia´GTI problems
hirsutism
T-cell immunosuppression
(image)
SIROLIMUS
(rapamycin)
(Everolimus,Temsirolimus)
similiar to Tacrolimus, binds FKBP 12, but the complex binds mTOR, mTOR has a central role in the IL2 activation pathway in lymphocytes, inhibit T-cell proliferation and maybe also B-cell proliferation and immunoglobulin production
Everolimus
and Temsirolimus are semisynthetic variants
They block T AND B cell function
sirolimus and everolimus are orally administered, temsirolimus iv.
Oral
availability of sirolimus is very variable and has a very long half-life (60h).
metabolized by CYP3A4
Use: kidney transplant and GVH. coronary stents(drug eluting stents),
Everolimus is used for breast cancer, kidney cc., neuroendocrine tumors, astrocytoma and sclerosis tuberosa,
temsirolismus for mantle-cell lymphoma and kidney cc.
SE: BM supression (thrombocytopenia!), hepatotoxicity, pneumonitis, hyperglycemia, hyperlipidemia, GI disturbance, headache
JAK signaling
two waves mediated by STAT5, JAK1+3 work in concert after IL-2-R is activated. if we block JAK 1+3 both waves are inhibited, if we block JAK 3 ( and PI3K+ mTOR partially) just the second wave is inhibited
TOFACITINIB
BARICITINIB, UPADACITINIB
(RUXOLITINIB)
Tofacitinib mostly inhibits JAK 1 and 3 – it blocks IL2 (4, 6, 7, 9, 15 and 21) mediated
pathways in T cells . reduces NK-cells, serum immunoglobulins and CRP
JAK1/JAK3 complex mediates signal from IL2-R-> Tofacitinib blocks IL (…) production ans secondary B-cell activation etc. …
JAK1 controls signal transduction of IL6 and interferon receptor
Baricitinib blocks JAK 1 and 2.
(Ruxolitinib JAK 2)
upadacitinib- JAK-1
They are low molecular weight drugs
Kinetics: Orally administered, good bioavailability 74%.
Tofacitinib has a short half-life
(prolonged release forms are available),
baricitinib and upadacitinib have longer halflife. Tofacitinib is mostly metabolized by CYP3A4 and lesser extend CYP2C19, baricitinib is mostly eliminated by kidney.
Use: they are used for RA. They can be used alone or in combination with MTX. The monotherapy is similarly effective as a MTX + antiTNFα combination. Other indications are under investigation (UC, CD, psoriasis, PsA, JIA, spondyloarthritis?).
(Ruxolitinib: polycytemia vera, myelofibrosis)
Also Organ allograft rejection,
Adverse effects: infections (airway)+ UTI, hyperlipidemia, CK elevation, liver enzyme elevation, BM suppression. , virus reactivation (HZV), TBC, LDL-level,
malignancies (e.g. lymphomas, lung, breast etc.), thromboembolism, hepatotoxicity,
anemia, thrombocytosis (baricitinib), neutropenia, GI perforations,
intersticial lung disease (tofacitinib)
(MTX combination is more dangerous)
black box warning for malgnancies and infections
Inhibitors of cytokine gene expression
Corticosteroids Prednisone Prednisolone Methylprednisolone Dexamethasone
They have both anti-inflammatory
action and immunosuppressant
effects
Mechanism of action
Binds to glucocorticoid receptors and the complex interacts with DNA to inhibit
gene transcription of inflammatory genes.
Decreased production of inflammatory mediators as prostaglandins,
leukotrienes, histamine, PAF, bradykinin.
Decreased production of cytokines IL-1, IL-2, interferon, TNF.
Stabilizes lysosomal membranes.
-Decrease generation of IgG, nitric oxide and histamine.
Inhibit antigen processing by macrophages.
Suppress T-cell helper function.
Decrease T lymphocyte proliferation
First line therapy for solid organ allografts & haematopoietic stem cell
transplantation.
Autoimmune diseases as refractory rheumatoid arthritis, systemic lupus
erythematosus (SLE), asthma.
Acute or chronic rejection of solid organ allografts.
Often used locally in dermatology
Adverse Effects Adrenal suppression Osteoporosis Hypercholesterolemia Hyperglycemia Hypertension Cataract Infection etc....
Methotrexate
Mech. of action: antimetabolite, Inhibition of DHF-reductase and depletion of folic acid leads to the blockade of DNA synthesis. The anti-inflammatory mechanism is likely the inhibition of AICAR transformilase by MTX-polyglutamates
◦ Inhibits several enzymes, including:
◦ dihydrofolate-reductase
◦ 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) formyltransferase (ATIC)
-AICAR inhibits competitively AMP deaminase - AMP accumulation, AMP is converted extracellular to adenosine which is a potent inhibitor of inflammation
- thymidylate synthase
accumulation of AICAR intracellularly and adenosine extracellularly
inhibition of both B and T-cell activation (interestingly TNF) macrophages and dendritic cells
secondary effects on PMC chemotaxis
-stimulates apoptosis in inflamatory cells
-inhibits proinflammatory cytokines linked to rheumatoid synovitis
upregulates adenosine receptors)
The polyglutamates of MTX persist in cells longer
In autoimmune diseases (RA, psoriasis – and other dermatological diseases, SLE, IBDs, JCA, PA, AS, POLYMYOSITIS, Dermatomyositis, Wegeners granulomatosis, giant cell arteritis, vasculitis)
If it is needed it can be given sc. as well.
oral bioavailability is 70%
hydroxychloroguin can reduce the excretion and increase the tubular reabsorption
30%bile excretion but primarily in kidney
Adverse effects:
#alopecia
#leukopenia, anemia
Liver enzyme elevation, hepatotoxocity
Fibrotic pneumonitis (hypersensitivity reaction)
Infection
GI problems (mucositis, stomatitis, diarrhea, ulcer, nausea)
(BM suppression)
Liver toxicity can be alleviated by leucovorin administration (next day after) or folic acid - reduce efficacy 10%
teratogenic
LEFLUNOMIDE
Teriflunomide
Mech. of action: They are inhibitors of dihydroorotate-dehydrogenase – this blocks
the pyrimidin synthesis. Arrest in G1 -phase. Teriflunomid is the activ metabolite of leflunomide.
They block T-cell proliferation and AB production of B-cells
secondarily increase in IL-10receptor mRNA; decrease in IL-8 receptor mRNA, an decrreased NF-kB activation (TNFa dependent)
Leflunomide is registered for RA and similarly as effective as MTX. Teriflunomide is
the active metabolite of leflunomide, it is used for remitting-relapsing MS
They are orally given
T1/2 is 2 weeks , enterohepaticcirculation also of active metabolite
Cholestyramine can accelerate the excretion
Adverse effects: liver enzyme elevation (up to sever liver dysfunction) diarrhea, skin exanthemas, alopecia, mild hypertension, weight gain increased BP, leukopenia and thrombocytopenia occur rarely
Azathioprine
It is transformed in the body to 6-mercaptopurine (6-MP) (book: 6-thioguanine). 6-MP turns to thio-IMP: it
blocks AMP and GMP synthesis.
◦ Inhibit phosphoribosyl-pyrophosphate-amido-transferase
(purine synthesis)
◦ Inhibit purine-base salvage
◦ Incorporates into nucleic acids
It is not known why azathioprin is a more specific immunosuppressive agent than 6-MP (better uptake or transformation in lymphocytes?)
blocks IL-2 secretion
Kinetic: Azathiopron is given orally or parenterally, Thio-IMP is catabolized by xanthin-oxydase.
(Cave allopurinol!)
rapid metabolizeres metabolise the drug 4x faster (bimodal metabolism in humans)
It mainly blocks cellular immunity
Use: kidney transplantations, IBDs, SLE, vasculitis diseases, (RA), PA, polymyositis, behcet disease, vasculitius
Adverse effects: BM suppression, liver toxicity (rarely: liver vein occlusion syndrome) GI disturbances, infection risk, lymphomas, allergic reaction
mycophenolate mofetil
It is isolated from Penicillium sp.
Mycophenolate is converted to mycophenolic acid (active form), blocks inosine-monophosphate-dehydrogenase (de novo GMP
synthesis). Lymphocyte (b-cell +T-cell) cannot use salvage-way for nucleotide uptake (they are
extremely sensitive to de-novo blockade), blocks proliferation
interferes with leukocyte adhesion downstream by inhibiting E-selectin and P-selectin, and intracellular adhesion molecule 1
Use: organ transplantations (1st of choice for heart, liver and kidney). Off label: GVH, SLE, RA, nephritis, myasthenia, psoriasis, wegeners granulomatosisa ) prevent chronic allograft vasculopathy in cardiac recioient patients (1st line), acute and chronic GVH,
generally an alternative to cyclosporin and tacrolimus for patients who do not tolerate those
Adverse effects: BM suppression, GI disorders, hypertension, nausea, dyspepsia, hepatotoxicity , infection and rarely malignancy, prevent chronic
CYCLOPHOSPHAMIDE
Derived from mustard gas, the group called bis(chlorethyl)amine
Prodrug: it turns in more steps in the body into phosphoramide mustard (the
active form) and into acrolein (inactive but toxic)
Phosphoramide mustard is a bifunctional alkytating agent. It alkylates DNA mostly on N7 of guanosine. It forms cross-links inside of DNA chain or between the two chains to prevent cell replication
It inhibits both T and B cells by 30-40%
Used: in SLE, systemic sclerosis,
vasculitis diseases, wegeners granulomatosis autoimmune glomerulonephritis, AI hemolytic anemia,
Transplant stem cell procedures, but does not prevent GVH disease,
Adverse effects: BM suppression (pancytopenia), oligospermia, ovarian dysfunction, GI, cardiac toxicity, hemorrhagic cystitis (akrolein), teratogenity and possible mutagenity, may cause hemorrhagic cystitis (treated with mesna), electrolyte disturbances
HIGH DOSE IMMUNGLOBULIN MIX
IVIG
It is isolated from the blood of healthy donors and iv. given.
The IG mix can be used for the treatment of IG deficit. It can also be used as an immune modulator: to neutralize superantigens and autoantibodies, to block Fc receptors of macrophages, to inhibit the complement and immuncomplex mediated tissue destruction.
Use: ITP, Kawasaki-Sy., Guillain-Barre Sy., Polymyositis, Vasculitis, SLE and IG deficit
Adverse effects: allergic reactions
Anti Rh0
(D): concentrated solution from human source. It must be given after delivery of
Rh+ baby of Rh- mother to suppress own antibody generation
POLYCLONAL ANTIBODIES
ANTI-LYMPHOCYTE AND ANTI-TYMOCYTE
GLOBULINS (ALG AND ATG)
They are isolated from blood of rabbits or horses immunized by human lymphocytes or thymocytes. It kills and blocks lymphocytes in the body.
Use: it is the most effective agents against acute rejection of grafts after transplantation. It is used if the possibility of rejection is high. In BM transplantation
the pretreatment of the graft by ALG reduces the possibility of GVH.
Adverse effects: dyspnoe, serumdisease, fever, GI disturbances
(Hyperimmunglobulins (human or animal) are used against viral infections (passive immunization for CMV, VZV, HBV, Rabies) or for toxicology (dioxin, snake venoms etc.). For RSV (palivizumab) and against B toxin of C. difficile (bezlotoxumab) monoclonal AB are available. )
-momab
100% murine
Mouse
-ximab
75% human
25% murine
Chimera
-zumab
95% human
5 % murin
Humanized
-umab
100% human
Human